[ { "text": "Right-Chiral Sneutrino LSP in mSUGRA: Event characteristics of NLSP at\n the LHC: We study a supersymmetric scenario where the lighter tau-sneutrino is the\nlightest supersymmetric particle, while the lighter stau-state is the next\nlightest. Such a scenario can be motivated within the framework of minimal\nsupergravity, with just the addition of a right-chiral neutrino superfield.\nSuch a spectrum leads to rather unusual signals of supersymmetry, showing\nstable tracks of the stau in the muon chambers. We study the event\ncharacteristics of the long-lived staus at the LHC and demonstrate that the\nstau tracks can be distinguished from the muonic ones through proper kinematic\ncuts which also enable one to remove all standard model backgrounds.", "category": "hep-ph" }, { "text": "Higgs Production and Decay via $e^+e^-\\rightarrow Z^0 H^0 \\rightarrow\n b\\bar bW^+W^-$ and Irreducible Backgrounds at the Next Linear Collider: The complete matrix element for $e^+e^-\\ar b\\bar bW^+W^-$ has been computed\nat tree--level and applied to $Z^0H^0$ production followed by $Z^0\\ar b\\bar b$\nand $H^0\\ar W^+W^-$, keeping into account all irreducible backgrounds, which\nare dominated by \\ttb production, at the Next Linear Colliders. We find that,\ndepending on the center of mass energies and on the search strategies, this\nchannel can be useful for the study of the parameters of the Standard Model\nHiggs boson over the most part of the heavy mass range.", "category": "hep-ph" }, { "text": "Evolution of transverse-momentum-dependent densities: We discuss different operator definitions of the transverse-momentum\ndependent (TMD) parton densities from the point of view of their\nrenormalization-group (RG) properties and UV evolution. We also consider the\nstructure of the gauge links (Wilson lines) in these operator definitions and\nexamine the role of the soft factor in the factorization formula within the TMD\napproach to semi-inclusive processes.", "category": "hep-ph" }, { "text": "Pair production of doubly heavy baryons: We analytically calculate the total and differential cross sections for the\npair production of doubly heavy baryons in the framework of diquark model. The\nprocesses of electron-positron and quark-antiquark annihilations are\nconsidered. The fractions of doubly heavy baryons in the yields of heavy quarks\nare evaluated numerically.", "category": "hep-ph" }, { "text": "Current-Target Correlations as a Probe of Delta_G/G in Polarized Deep\n Inelastic Scattering: The measurement of the polarized gluon distribution function Delta_G/G using\ncurrent-target correlations in the Breit frame of deep inelastic scattering is\nproposed. The approach is illustrated using a Monte Carlo simulation of\npolarized $ep$-collisions for HERA energies.", "category": "hep-ph" }, { "text": "Effects of non-standard interaction on microscopic black holes from\n ultra-high energy neutrinos: If the universe has more than 4-dimensions, the TeV scale gravity theories\npredict formation of microscopic black holes due to interaction of ultra high\nenergy neutrinos coming from some extragalactic origin with the nucleons\npresent in the Earth's atmosphere. The decay of these black holes can generate\nhigh multiplicity events which can be detected through neutrino telescopes.\nUltra high energy neutrinos can also produce events without the formation of\nblack holes which can be distinguished from the black hole events depending on\ntheir topological structure. In this work we study the effects of non-standard\ninteraction on the production of these shower events. We find that new physics\nhas inconsequential impact on the number of events produced through the\ngeneration of black holes. For events produced without the formation of black\nholes, new physics can only provide a marginal deviation. Therefore a large\nenhancement in the number of shower events over the standard model prediction\ncan provide unambiguous signatures of TeV scale gravity in the form of\nmicroscopic black hole production.", "category": "hep-ph" }, { "text": "Cosmological Axion and Quark Nugget Dark Matter Model: We study a dark matter (DM) model offering a very natural explanation of two\n(naively unrelated) problems in cosmology: the observed relation $\\Omega_{\\rm\nDM}\\sim\\Omega_{\\rm visible}$ and the observed asymmetry between matter and\nantimatter in the Universe, known as the \"baryogenesis\" problem. In this\nframework, both types of matter (dark and visible) have the same QCD origin,\nform at the same QCD epoch, and both proportional to one and the same\ndimensional parameter of the system, $\\Lambda_{\\rm QCD}$, which explains how\nthese two, naively distinct, problems could be intimately related, and could be\nsolved simultaneously within the same framework. More specifically, the DM in\nthis model is composed by two different ingredients: the (well- studied) DM\naxions and (less-studied) the quark nuggets made of matter or antimatter. The\nfocus of the present work is the quantitative analysis of the relation between\nthese two distinct components contributing to the dark sector of the theory\ndetermined by $\\Omega_{\\rm DM}\\equiv [\\Omega_{\\rm DM}(\\rm nuggets)+ \\Omega_{\\rm\nDM}(\\rm axion)]$. We argue that the nugget's DM component always traces the\nvisible matter density, i.e. $\\Omega_{\\rm DM}(\\rm nuggets)\\sim\\Omega_{\\rm\nvisible}$ and this feature is not sensitive to the parameters of the system\nsuch as the axion mass $m_a$ or the misalignment angle $\\theta_0$. It should be\ncontrasted with conventional axion production mechanism due to the misalignment\nwhen $\\Omega_{\\rm DM}(\\rm axion)$ is highly sensitive to the axion mass $m_a$\nand the initial misalignment angle $\\theta_0$. We also discuss the constraints\non this model related to the inflationary scale $H_I$, non-observation of the\nisocurvature perturbations, $r_T < 0.12$, and also, varies axions search\nexperiments.", "category": "hep-ph" }, { "text": "The 14 TeV LHC Takes Aim at SUSY: A No-Scale Supergravity Model for LHC\n Run 2: The Supergravity model named No-Scale ${\\cal F}$-$SU(5)$, which is based upon\nthe flipped $SU$(5) Grand Unified Theory (GUT) with additional TeV-scale\nvector-like flippon multiplets, has been partially probed during the LHC Run 1\nat 7-8 TeV, though the majority of its model space remains viable and should be\naccessible by the 13-14 TeV LHC during Run 2. The model framework possesses the\nrather unique capacity to provide a light CP-even Higgs boson mass in the\nfavored 124-126 GeV window while simultaneously retaining a testably light\nsupersymmetry (SUSY) spectrum. We summarize the outlook for No-Scale ${\\cal\nF}$-$SU(5)$ at the 13-14 TeV LHC and review a promising methodology for the\ndiscrimination of its long-chain cascade decay signature. We further show that\nproportional dependence of all model scales upon the unified gaugino mass\n$M_{1/2}$ minimizes electroweak fine-tuning, allowing the $Z$-boson mass $M_Z$\nto be expressed as an explicit function of $M_{1/2}$, $M_Z^2 = M_Z^2\n(M_{1/2}^2)$, with implicit dependence upon a dimensionless ratio $c$ of the\nsupersymmetric Higgs mixing parameter $\\mu$ and $M_{1/2}$. Finally, we\nelucidate an empirical connection between recent scalar tensor measurements and\nNo-Scale Supergravity cosmological models that mimic the Starobinsky model of\ninflation.", "category": "hep-ph" }, { "text": "Dark top partner: Composite Higgs models with extended symmetries can feature mesonic dark\nmatter candidates. In fundamental CHMs, the origin of dark parity can be\nexplained in the UV theory. Combined with top partial compositeness, this leads\nto non-chiral Yukawa interaction connecting mesonic DM with one dark top\npartner and one SM top. We examine the DM phenomenology in SU(6)/SO(6) and\nSU(6)/Sp(6) CHMs with the presence of dark top partners. Phenomenological\nconstraints require the mass of top partner in even parity to be of the\nmulti-TeV order.", "category": "hep-ph" }, { "text": "Precision measurements of IVB parameters and bounds on new physics: The main purpose of this thesis is to discuss the impact of electroweak\nprecision measurements on the present knowledge of particle physics, both in\nthe framework of the Standard Model and of its most straightforward extensions.\nIn Chapter 1 we give a general overview of the electroweak sector of the SM and\nof SUSY phenomenology. In Chapter 2 we deal with different definitions of the\nelectroweak mixing angle, with particular attention to the relation between the\nphenomenological angle $\\theta$ and the MS parameter $\\hat\\theta$. In Chapter 3\nwe use results found in the previous chapter to discuss in detail how both the\ndecoupling and the non-decoupling approach to the running of coupling constants\nin the MS scheme produce the same numerical value of $m_{GUT}$, despite of the\ndifferent initial conditions. In Chapter 4 we derive simple analytical formulas\nfor the contribution of a chargino almost degenerate with the lightest\nneutralino to electroweak observables, showing that in the case of wino\ndomination the study of oblique corrections allows a concrete improvement of\nexperimental bounds on chargino mass. Finally, in Chapter 5 we consider the\npossibility of extra fermion generations, proving that they are strongly\ndisfavoured by the present experimental data if all particles are heavier that\nZ-boson, while for the specific case of the extra neutrino around 50 GeV in\nmass (still allowed by experimental data) the quality of the fit is not worse\nthan the SM.", "category": "hep-ph" }, { "text": "Search for neutrinoless double beta decay with enriched 76Ge in Gran\n Sasso 1990-2003: The results of the HEIDELBERG-MOSCOW experiment which searches with 11 kg of\nenriched 76Ge for double beta decay in the GRAN Sasso underground laboratory\nare presented for the full running period August 1990 - May 2003. The duty\ncycle of the experiment was ~80%, the collected statistics is 71.7 kg y. The\nbackground achieved in the energy region of the Q value for double beta decay\nis 0.11 events/ kg y keV. The two-neutrino accompanied half-life is determined\non the basis of more than 100 000 events. The confidence level for the\nneutrinoless signal has been improved to 4.2 sigma.", "category": "hep-ph" }, { "text": "Sum-rule constraints on possible diphoton resonances at LHC: The study of the forward scattering amplitude $V(k,\\lambda) V(k'\\lambda')\\to\nV(k,\\lambda) V(k',\\lambda')$ of real massless gauge bosons $V$, e.g. photons or\ngluons, leads to a sum-rule that can be used to investigate beyond the Standard\nModel signals at LHC in the $\\gamma\\gamma$ channel. The sum-rule only relies on\ngeneral properties such as analyticity, unitarity and crossing. We use the now\nburied 750 GeV diphoton resonance as a case of study to exemplify the\nconstraints that the forward sum-rule requires to any new physics candidate. In\nthe case of a large $\\gamma\\gamma$ or $gg$ partial width, of the order of 10\nGeV in our 750 GeV analysis, one finds that an infinite tower of states with\nspin $J_R=2$ and higher must be ultimately incorporated to the beyond Standard\nModel theory in order to fulfill the sum-rule. We expect these techniques may\nbe useful in next diphoton searches at LHC and future colliders.", "category": "hep-ph" }, { "text": "Little Higgs Model Discrimination at the LHC and ILC: We propose a means to discriminate between the two basic variants of Little\nHiggs models, the Product Group and Simple Group models, at the next generation\nof colliders. It relies on a special coupling of light pseudoscalar particles\npresent in Little Higgs models, the pseudoaxions, to the Z and the Higgs boson,\nwhich is present only in Simple Group models. We discuss the collider\nphenomenology of the pseudoaxion in the presence of such a coupling at the LHC,\nwhere resonant production and decay of either the Higgs or the pseudoaxion\ninduced by that coupling can be observed for much of parameter space. The full\nallowed range of parameters, including regions where the observability is\nlimited at the LHC, is covered by a future ILC, where double scalar production\nwould be a golden channel to look for.", "category": "hep-ph" }, { "text": "Muon transverse polarization in the $K_{l2\u03b3}$ decay in SM: The muon transverse polarization in the $K^+ \\to \\mu^+ \\nu \\gamma$ process\ninduced by the electromagnetic final state interaction is calculated in the\nframework of Standard Model. It is shown that one loop contributions lead to a\nnonvanihing muon transverse polarization. The value of the muon transverse\npolarization averaged over the kinematical region of $E_\\gamma \\geq 20$ MeV is\nequal to $5.63 \\times 10^{-4}$.", "category": "hep-ph" }, { "text": "Lifetime of quasiparticles in hot gauge theories: The perturbative calculation of the lifetime of charged excitations in\nultrarelativistic plasmas is plagued with infrared divergences which are not\neliminated by the screening corrections. The physical processes responsible for\nthese divergences are the collisions involving the exchange of longwavelength,\nquasistatic, magnetic gluons (or photons), which are not screened by plasma\neffects. In QED, the leading divergences can be resummed in a non-perturbative\ntreatement based on a generalization of the Bloch-Nordsieck model at finite\ntemperature. The resulting expression of the fermion propagator is free of\ninfrared problems, and exhibits a ``non-exponential'' damping at large times:\n$S_R(t)\\sim exp {-\\alpha T t ln\\omega_pt}$, where $\\omega_p=eT/3$ is the plasma\nfrequency and $\\alpha=e^2/4\\pi$.", "category": "hep-ph" }, { "text": "Coulomb-Nuclear Interference:the Latest Modification: We argue that the account of Coulomb-nuclear interference (CNI) in the\ndifferential cross-section of elastic $ pp $ scattering may be easily treated\nwithout introduction of intermediate IR regularization (\"photon mass\"). We also\nindicate that the parametrization used earlier misses some terms of the second\norder in $ \\alpha $ while it contains a superfluous term of the first order.", "category": "hep-ph" }, { "text": "Higgs Radiation off Top Quarks at the Tevatron and the LHC: Higgs bosons can be searched for in the channels $p\\bar p/pp\\to t\\bar tH+X$\nat the Tevatron and the LHC. We have calculated the QCD corrections to these\nprocesses in the Standard Model at next-to-leading order. The higher-order\ncorrections reduce the renormalization and factorization scale dependence\nconsiderably and stabilize the theoretical predictions for the cross sections.\nAt the central scale $\\mu=(2m_t+M_H)/2$ the properly defined $K$ factors are\nslightly below unity for the Tevatron ($K \\sim 0.8$) and slightly above unity\nfor the LHC ($K \\sim 1.2$).", "category": "hep-ph" }, { "text": "A Linear Sigma Model with Three Flavors and Vector and Axial-Vector\n Mesons: We outline the extension of the globally chirally invariant Nf = 2 linear\nsigma model with vector and axial-vector degrees of freedom to Nf=3. We present\npreliminary results concerning the scalar meson masses.", "category": "hep-ph" }, { "text": "Dark Photon Dark Matter from Cosmic Strings and Gravitational Wave\n Background: Dark photon dark matter may be produced by the cosmic strings in association\nwith the dark U(1) gauge symmetry breaking. We perform three-dimensional\nlattice simulations of the Abelian-Higgs model and follow the evolution of\ncosmic strings. In particular, we simulate the case of (very) light vector\nboson and find that such vector bosons are efficiently produced by the collapse\nof small loops while the production is inefficient in the case of heavy vector\nboson. We calculate the spectrum of the gravitational wave background produced\nby the cosmic string loops for the light vector boson case and find\ncharacteristic features in the spectrum, which can serve as a probe of the dark\nphoton dark matter scenario. In particular, we find that the current\nground-based detectors may be sensitive to such gravitational wave signals and\nalso on-going/future pulsar timing observations give stringent constraint on\nthe dark photon dark matter scenario.", "category": "hep-ph" }, { "text": "$\u03c0K$ sum rules and the SU(3) chiral expansion: A recently proposed set of sum rules, based on the pion-Kaon scattering\namplitudes and their crossing-symmetric conjugates are analysed in detail. A\nkey role is played by the $l=0$ $\\pi\\pi\\to K\\overline K$ amplitude which\nrequires an extrapolation to be performed. It is shown how this is tightly\nconstrained from analyticity, chiral counting and the available experimental\ndata, and its stability is tested. A re-evaluation of the $O(p^4)$ chiral\ncouplings $L_1$, $L_2$, $L_3$ is obtained, as well as a new evaluation of the\nlarge $N_c$ suppressed coupling $L_4$.", "category": "hep-ph" }, { "text": "Proposed Tests of CPT Symmetry Using D Mesons: Parameters describing CPT violation are extracted from a variety of rate\nasymmetries in the neutral-$D$ system. The precision to which these parameters\ncould be measured in present and planned machines is examined.", "category": "hep-ph" }, { "text": "Low scale quantum gravity in gauge-Higgs unified models: We consider the scale at which gravity becomes strong in linearized General\nRelativity coupled to the gauge-Higgs unified(GHU) model. We also discuss the\nunitarity of S-matrix in the same framework. The Kaluza-Klein(KK) gauge bosons,\nKK scalars and KK fermions in the GHU models can drastically change the strong\ngravity scale and the unitarity violation scale. In particular we consider two\nmodels GHU_SM and GHU_MSSM which have the zero modes corresponding to the\nparticle content of the Standard Model and the Minimal Supersymmetric Standard\nModel, respectively. We find that the strong gravity scale could be lowered as\nmuch as 10^13 (10^14) GeV in the GHU_SM (GHU_MSSM) for one extra dimension\ntaking 1 TeV as the compactification scale. It is also shown that these scales\nare proportional to the inverse of the number of extra dimensions d. In the\nd=10 case, they could be lowered up to 10^5 GeV for both models. We also find\nthat the maximum compactification scales of extra dimensions quickly converge\ninto one special scale M_O near Planck scale or equivalently into one common\nradius R_0 irrespectively of d as the number of zero modes increases. It may\nmean that all extra dimensions emerge with the same radius near Planck scale.\nIn addition, it is shown that the supersymmetry can help to remove the\ndiscordance between the strong gravity scale and the unitarity violation scale.", "category": "hep-ph" }, { "text": "Transverse momentum distributions of valence quark in light and heavy\n vector mesons: We study the leading-twist time-reversal even transverse momentum dependent\nparton distribution functions (TMDs) of light and heavy vector mesons, i.e.,\nthe $\\rho$, $J/\\psi$ and $\\Upsilon$. We employ the leading Fock-state light\nfront wave functions (LF-LFWFs) of $\\rho$ and $J/\\psi$ from our recent study,\nand supplement with $\\Upsilon$'s LF-LFWFs. These LF-LFWFs are extracted from\ndynamically solved Bethe-Salpeter wave functions. The vector meson TMDs are\nthen studied with the light front overlap representation at leading Fock-state.\nAll the obtained TMDs are non-vanishing and evolve with current quark mass, in\nparticular the tensor polarized TMDs $f_{1LT}$ and $f_{1TT}$ which undergo a\nsign flip. The $\\rho$ TMDs are compared with other model studies and agreement\nis found, aside from $f_{1LT}$ and $f_{1TT}$. Finally, the collinear PDFs of\nvector mesons are studied. The $\\rho$'s valence PDFs $f_{1,v}(x)$ and\n$g_{1L,v}(x)$ are evolved to the scale of 2.4 GeV, with their first three\nmoments compared to lattice QCD prediction. The qualitative behavior of tensor\npolarized PDF $f_{1LL}(x)$ in $\\rho$ at large $x$ is also discussed.", "category": "hep-ph" }, { "text": "The Friedberg-Lee model at finite temperature and density: The Friedberg-Lee model is studied at finite temperature and density. By\nusing the finite temperature field theory, the effective potential of the\nFriedberg-Lee model and the bag constant $B(T)$ and $B(T,\\mu)$ have been\ncalculated at different temperatures and densities. It is shown that there is a\ncritical temperature $T_{C}\\simeq 106.6 \\mathrm{MeV}$ when $\\mu=0 \\mathrm{MeV}$\nand a critical chemical potential $\\mu \\simeq 223.1 \\mathrm{MeV}$ for fixing\nthe temperature at $T=50 \\mathrm{MeV}$. We also calculate the soliton solutions\nof the Friedberg-Lee model at finite temperature and density. It turns out that\nwhen $T\\leq T_{C}$ (or $\\mu \\leq \\mu_C$), there is a bag constant $B(T)$ (or\n$B(T,\\mu)$) and the soliton solutions are stable. However, when $T>T_{C}$ (or\n$\\mu>\\mu_C$) the bag constant $B(T)=0 \\mathrm{MeV}$ (or $B(T,\\mu)=0\n\\mathrm{MeV}$) and there is no soliton solution anymore, therefore, the\nconfinement of quarks disappears quickly.", "category": "hep-ph" }, { "text": "Anomalous $Z'$ effects in the WW channel at NLC: We consider the virtual signals of a $Z'$ of very general type in the process\n$e^+e^-\\to W^+W^-$ at a future linear collider (NLC). We show that possible\ndeviations from the SM predictions in this channel are related to similar\ndeviations in the purely leptonic one in a way that is only characteristic of\nthis $Z'$ model, and not in general of possible competitor models with\nanomalous gauge couplings.", "category": "hep-ph" }, { "text": "Mass-degenerate Higgs bosons at 125 GeV in the Two-Higgs-Doublet Model: The analysis of the Higgs boson data by the ATLAS and CMS Collaborations\nappears to exhibit an excess of h --> gamma\\gamma events above the Standard\nModel (SM) expectations; whereas no significant excess is observed in h --> ZZ*\n--> {four lepton} events, albeit with large statistical uncertainty due to the\nsmall data sample. These results (assuming they persist with further data)\ncould be explained by a pair of nearly mass-degenerate scalars, one of which is\na SM-like Higgs boson and the other is a scalar with suppressed couplings to\nW+W- and ZZ. In the two Higgs doublet model, the observed \\gamma\\gamma and ZZ*\n--> {four lepton} data can be reproduced by an approximately degenerate CP-even\n(h) and CP-odd (A) Higgs boson for values of \\sin(\\beta-\\alpha) near unity and\n0.7 < \\tan\\beta < 1. An enhanced \\gamma\\gamma signal can also arise in cases\nwhere m_h ~ m_H, m_H ~ m_A, or m_h ~ m_H ~ m_A. Since the ZZ* --> {four lepton}\nsignal derives primarily from a SM-like Higgs boson whereas the \\gamma\\gamma\nsignal receives contributions from two (or more) nearly mass-degenerate states,\none would expect a slightly different invariant mass peak in the ZZ* --> {four\nlepton} and \\gamma\\gamma channels. The phenomenological consequences of such\nmodels can be tested with additional Higgs data that will be collected at the\nLHC in the near future.", "category": "hep-ph" }, { "text": "BEACH 2014 Theory Summary: I summarize key aspects of the quest for physics beyond the Standard Model in\nflavour physics as discussed at the BEACH 2014 conference in Birmingham.", "category": "hep-ph" }, { "text": "Probing the lightest new gauge boson $B_H$ in the littlest Higgs model\n via the processes $\u03b3\u03b3\\to f\\bar{f}B_H$ at the ILC: The neutral gauge boson $B_H$ with the mass of hundreds GeV, is the lightest\nparticle predicted by the littlest Higgs(LH) model, and such particle should be\nthe first signal of the LH model at the planed ILC if it exists indeed. In this\npaper, we study some processes of the $B_H$ production associated with the\nfermion pair at the ILC, i.e., $\\gamma\\gamma\\to f\\bar{f}B_{H}$. The studies\nshow that the most promising processes to detect $B_H$ among $\\gamma\\gamma\\to\nf\\bar{f}B_{H}$ are $\\gamma\\gamma\\to l'^+l'^-B_{H}(l'=e,\\mu)$, and they can\nproduce the sufficient signals in most parameter space preferred by the\nelectroweak precision data at the ILC. On the other hand, the signal produced\nvia the certain $B_H$ decay modes is typical and such signal can be easily\nidentified from the SM background. Therefore, $B_H$, the lightest gauge boson\nin the LH model would be detectable at the photon collider realized at the ILC.", "category": "hep-ph" }, { "text": "Uncovering the Root of LEFT in SMEFT: At energies below the electroweak scale, baryon number $B$ and lepton number\n$L$ violating processes are of significant importance in identifying the nature\nof UV extensions of the Standard Model. The imprint of UV theories on\nlow-energy measurements can be calculated to a high accuracy using the\ntheoretical framework of the Low Energy Effective Theory (LEFT). Using $B,\\; L$\nand the operators' dimensions as classifying characteristics, we construct a\nnetwork connecting operator classes of the LEFT with the Standard Model\nEffective Theory (SMEFT). Following the links of this network, the contact\ninteractions described by the effective operators of LEFT can be unambiguously\nembedded into those of SMEFT, which enables us to constrain the possible\nrealisations of UV theories. In turn, this can help to prioritise low energy\nmeasurements with the aim of comprehensively testing all classes of LEFT and\nSMEFT operators.", "category": "hep-ph" }, { "text": "Delta I=1/2 and epsilon'/epsilon in Large-Nc QCD: We present new results for the matrix elements of the Q_6 and Q_4 penguin\noperators, evaluated in a large-Nc approach which incorporates important\nO(N_c^2\\frac{n_f}{N_c}) unfactorized contributions. Our approach shows analytic\nmatching between short- and long-distance scale dependences within dimensional\nrenormalization schemes, such as MS-bar. Numerically, we find that there is a\nlarge positive contribution to the Delta I =1/2 matrix element of Q_6 and hence\nto the direct CP-violation parameter epsilon'/epsilon. We also present results\nfor the Delta I = 1/2 rule in K -> pi pi amplitudes, which incorporate the\nrelated and important ``eye-diagram'' contributions of O(N_c^2\\frac{1}{N_c})\nfrom the Q_2 operator (i.e. the penguin-like contraction). The results lead to\nan enhancement of the Delta I = 1/2 effective coupling. The origin of the large\nunfactorized contributions which we find is discussed in terms of the relevant\nscales of the problem.", "category": "hep-ph" }, { "text": "An improvement of the Moliere-Fano multiple scattering theory: In the framework of unitary Glauber approximation for particle-atom\nscattering, we develop the general formalism of the Moliere-Fano multiple\nscattering theory (M-F theory) on the basis of reconstruction of the\ngeneralized optical theorem in it. We present rigorous relations between some\nexact and first-order parameters of the Moliere multiple scattering theory,\ninstead of the approximate one obtained in the original paper by Moliere. We\nconsider the relative unitarity corrections and the Coulomb corrections to the\nquantities of the M-F theory. Also, we examine their Z dependence in the range\nof nuclear charge, from Z=4 to Z=92. Additionally, we show the difference\nbetween our results and those of Moliere over this Z range.", "category": "hep-ph" }, { "text": "Generalized Dirac-Pauli equation and spin light of neutrino in\n magnetized matter: We consider propagation of a massive neutrino in matter within the quantum\napproach based on the two equations for the neutrino field: the first one is\nthe Dirac-Pauli equation for a massive neutrino in an external magnetic field\ngeneralized on the inclusion of effects of the background matter; the second\none is the modified Dirac equation derived directly from the neutrino-matter\ninteraction Lagrangian. On the basis of these two equations the quantum theory\nof a neutrino moving in the background matter is developed (the exact solutions\nof these equations are found and classified over the neutrino spin states, the\ncorresponding energy spectra are also derived). Using these solutions we study\nwithin the quantum approach the spin light of neutrino ($SL\\nu$) in matter with\nthe effect of a longitudinal magnetic field being also incorporated. In\nparticular, the $SL\\nu$ radiation rate and total power are derived. The use of\nthe generalized Dirac-Pauli equation also enables us to consider the $SL\\nu$ in\nmatter polarized under the influence of strong magnetic field.", "category": "hep-ph" }, { "text": "A semi-analytic method to compute Feynman integrals applied to four-loop\n corrections to the $\\overline{\\rm MS}$-pole quark mass relation: We describe a method to numerically compute multi-loop integrals, depending\non one dimensionless parameter $x$ and the dimension $d$, in the whole\nkinematic range of $x$. The method is based on differential equations, which,\nhowever, do not require any special form, and series expansions around singular\nand regular points. This method provides results well suited for fast numerical\nevaluation and sufficiently precise for phenomenological applications. We apply\nthe approach to four-loop on-shell integrals and compute the coefficient\nfunction of eight colour structures in the relation between the mass of a heavy\nquark defined in the $\\overline{\\rm MS}$ and the on-shell scheme allowing for a\nsecond non-zero quark mass. We also obtain analytic results for these eight\ncoefficient functions in terms of harmonic polylogarithms and iterated\nintegrals. This allows for a validation of the numerical accuracy.", "category": "hep-ph" }, { "text": "Diquarks and antiquarks in exotics: a menage a trois and a menage a\n quatre: A menage a trois is very different from an ordinary family. Similarly, exotic\nhadrons with both qq and qbar q pairs have important color-space correlations\nthat are completely absent in ordinary mesons and baryons. The presence of both\ntypes of pairs requires attention to the basic QCD physics that the q qbar\ninteraction is much stronger than the qq interaction. This new physics in\nmultiquark systems produces color structures totally different from those of\nnormal hadrons, for example the ud system is utterly unlike the ud diquark in\nthe uds Lambda baryon. The color-space correlations produce unusual\nexperimental properties in tetraquarks with heavy quark pairs which may be\nrelevant for newly discovered mesons like the X(3872) resonance. Tetraquark\nmasses can be below the two-meson threshold for sufficiently high quark masses.\nA simple model calculation shows the b q bbar ubar and b q cbar qbar\ntetraquarks below the B Bbar and B Dbar thresholds. Some of these states have\nexotic electric charge and their decays might have striking signatures\ninvolving monoenergetic photons and/or pions.", "category": "hep-ph" }, { "text": "Spatial densities of momentum and forces in spin-one hadrons: Densities associated with the energy-momentum tensor are calculated for\nspin-one targets. These calculations are done in a light front formalism, which\naccounts for relativistic effects due to boosts and allows for arbitrary\nspatial localization of the target. These densities include the distribution of\nmomentum, angular momentum, and pressures over a two-dimensional plane\ntransverse to the light front. Results are obtained for both longitudinally and\ntransversely polarized targets, and the formalism is tailored to allow the\npossibility of massless targets. The momentum density and pressure\ndistributions are calculated for a deuteron target in a light cone convolution\nmodel, with which the properties of this model (such as helicity dependence of\nthe densities) is illustrated.", "category": "hep-ph" }, { "text": "Non-Hermitian Perturbations to the Fritzsch Textures of Lepton and Quark\n Mass Matrices: We show that non-Hermitian and nearest-neighbor-interacting perturbations to\nthe Fritzsch textures of lepton and quark mass matrices can make both of them\nfit current experimental data very well. In particular, we obtain \\theta_{23}\n\\simeq 45^\\circ for the atmospheric neutrino mixing angle and predict\n\\theta_{13} \\simeq 3^\\circ to 6^\\circ for the smallest neutrino mixing angle\nwhen the perturbations in the lepton sector are at the 20% level. The same\nlevel of perturbations is required in the quark sector, where the Jarlskog\ninvariant of CP violation is about 3.7 \\times 10^{-5}. In comparison, the\nstrength of leptonic CP violation is possible to reach about 1.5 \\times 10^{-2}\nin neutrino oscillations.", "category": "hep-ph" }, { "text": "NLO Corrections to Heavy Quark Production with Polarized Beams: We present a calculation of the NLO QCD corrections to heavy flavor\nphotoproduction with longitudinally polarized beams. We apply our results to\nstudy the spin asymmetry for total charm quark production which will be used\nfor a first direct determination of Delta g by the COMPASS experiment. We also\nbriefly discuss the main theoretical uncertainties inherent in this\ncalculation.", "category": "hep-ph" }, { "text": "Probing wrong-sign Yukawa couplings at the LHC and a future linear\n collider: We consider the two-Higgs-doublet model as a framework in which to evaluate\nthe viability of scenarios in which the sign of the coupling of the observed\nHiggs boson to down-type fermions (in particular, $b$-quark pairs) is opposite\nto that of the Standard Model (SM), while at the same time all other tree-level\ncouplings are close to the SM values. We show that, whereas such a scenario is\nconsistent with current LHC observations, both future running at the LHC and a\nfuture $e^+ e^-$ linear collider could determine the sign of the Higgs coupling\nto $b$-quark pairs. Discrimination is possible for two reasons. First, the\ninterference between the $b$-quark and the $t$-quark loop contributions to the\n$ggh$ coupling changes sign. Second, the charged-Higgs loop contribution to the\n$\\gamma \\gamma h$ coupling is large and fairly constant up to the largest\ncharged-Higgs mass allowed by tree-level unitarity bounds when the $b$-quark\nYukawa coupling has the opposite sign from that of the SM (the change in sign\nof the interference terms between the $b$-quark loop and the $W$ and $t$ loops\nhaving negligible impact).", "category": "hep-ph" }, { "text": "Strongly interacting matter from holographic QCD model: We introduce the 5-dimension dynamical holographic QCD model, which is\nconstructed in the graviton-dilaton-scalar framework with the dilaton\nbackground field $\\Phi$ and the scalar field $X$ responsible for the\ngluodynamics and chiral dynamics, respectively. We review our results on the\nhadron spectra including the glueball and light meson spectra, QCD phase\ntransitions and transport properties in the framework of the dynamical\nholographic QCD model.", "category": "hep-ph" }, { "text": "Twist-4 Matrix Elements of the Nucleon from Recent DIS Data at CERN and\n SLAC: We analyse the recent precision measurements of the lepton-hadron deep\ninelastic scattering at CERN and SLAC to extract model independent constraints\namong the nucleon matrix elements of the twist-4 operators. We also study a\nparameterization of these matrix elements and point out the possibility that\nthe matrix elements of the quark-gluon mixed operator has a negative value of\nthe order of $- (400 \\pm 100\\ {\\rm MeV})^2$ at 5 GeV$^2$ renormalization scale.", "category": "hep-ph" }, { "text": "Holographic Picture of Heavy Vector Meson Melting: The fraction of heavy vector mesons produced in a heavy ion collision, as\ncompared to a proton proton collision, serves as an important indication of the\nformation of a thermal medium, the quark gluon plasma. This sort of analysis\nstrongly depends on understanding the thermal effects of a medium like the\nplasma on the states of heavy mesons. In particular, it is crucial to know the\ntemperature ranges where they undergo a thermal dissociation, or melting.\nAdS/QCD models are know to provide an important tool for the calculation of\nhadronic masses, but in general are not consistent with the observation that\ndecay constants of heavy vector mesons decrease with excitation level. It has\nrecently been shown that this problem can be overcome using a soft wall\nbackground and introducing an extra energy parameter, through the calculation\nof correlation functions at a finite position of anti-de Sitter space. This\napproach leads to the evaluation of masses and decay constants of S wave\nquarkonium states with just one flavor dependent and one flavor independent\nparameters. Here we extend this more realistic model to finite temperatures and\nanalyse the thermal behavior of the states $1S, 2S$ and $ 3S$ of bottomonium\nand charmonium. The corresponding spectral function exhibits a consistent\npicture for the melting of the states where, for each flavor, the higher\nexcitations melt at lower temperatures. We estimate for these six states, the\nenergy ranges in which the heavy vector mesons undergo a transition from a well\ndefined peak in the spectral function to complete melting in the thermal\nmedium. A very clear distinction between the heavy flavors emerges, with\nbottomonium state $\\Upsilon (1S)$ surviving deconfinemet transition at\ntemperatures much larger than the critical deconfinement temperature of the\nmedium.", "category": "hep-ph" }, { "text": "Running Flavor Number and Asymptotic Freedom in the Normal Phase of QED: In the normal phase (where no dynamical fermion mass generation occurs) of\nthe D-dimensional quantum electrodynamics with $N_f$ flavors of fermions, we\nderive an integral equation which should be satisfied by (the inverse of) the\nwave function renormalization of the fermion in the Landau gauge. For this we\nuse the inverse Landau-Khalatnikov transformation connecting the nonlocal gauge\nwith the Landau gauge. This leads to a similar equation for the running flavor\nnumber in the framework of the $1/N_f$ resumed Schwinger-Dyson equation.\nSolving the equation analytically and numerically, we study the infrared\nbehavior and the critical exponent of the 3-dimensional QED (QED$_3$). This\nconfirms that the flavor number in QED$_3$ runs according to the $\\beta$\nfunction which is consistent with the asymptotic freedom as that in\n4-dimensional QCD.", "category": "hep-ph" }, { "text": "Quantitative Study of Geometrical Scaling in Deep Inelastic Scattering\n at HERA: We propose a method to assess the quality of geometrical scaling in Deep\nInelastic Scattering and apply it to the combined HERA data on $\\gamma^{\\ast}p$\ncross-section. Using two different approaches based on Bjorken $x$ binning and\nbinning in $\\gamma^{\\ast}p$ scattering energy $W$, we show that geometrical\nscaling in variable $\\tau\\sim Q^{2} x^{\\lambda}$ works well up to Bjorken $x$'s\n0.1. The corresponding value of exponent $\\lambda$ is 0.32 -- 0.34.", "category": "hep-ph" }, { "text": "Bounds on the Higgs-Boson Mass in the Presence of Non-Standard\n Interactions: The triviality and vacuum stability bounds on the Higgs-boson mass are\nrevisited in the presence of new interactions parameterized in a\nmodel-independent way by an effective lagrangian. When the scale of new physics\nis below 50 TeV the triviality bound is unchanged but the stability lower bound\nis increased by 40-60 GeV. Should the Higgs-boson mass be close to its current\nlower experimental limit, this leads to the possibility of new physics at the\nscale of a few TeV, even for modest values of the effective lagrangian\nparameters.", "category": "hep-ph" }, { "text": "The New Pentaquarks in the Diquark Model: Pentaquark baryons are a natural expectation of an extended picture of\nhadrons where quarks and diquarks are the fundamental units. The parity/mass\npattern observed, when compared to that of exotic mesons, appears as the\nfootprint of a compact five-quark structure. What has been learned from the\nX,Y,Z phenomenology informs about the newly found pentaquark structure and\nsuggests further experimental tests and directions to be explored.", "category": "hep-ph" }, { "text": "Heavy-Quark Mass and Heavy-Meson Decay Constants from QCD Sum Rules: We present a sum-rule extraction of heavy-meson decay constants from the\ntwo-point correlator of heavy-light pseudoscalar currents. Our main concern is\nto control the uncertainties of the decay constants, induced by both input QCD\nparameters and limited accuracy of the sum-rule method. Gaining this control is\npossible by applying our novel procedure for the extraction of hadron\nobservables utilizing Borel-parameter-depending dual thresholds. For the\ncharmed mesons, we obtain f_D = 206.2 \\pm 7.3 (OPE) \\pm 5.1 (syst) MeV and\nf_{D_s} = 245.3 \\pm 15.7 (OPE) \\pm 4.5 (syst) MeV. For the beauty mesons, the\ndecay constants prove to be extremely sensitive to the exact value of the\nb-quark MS-bar mass m_b(m_b). Matching our sum-rule prediction for f_B to the\nlattice findings, the very accurate b-mass value m_b(m_b) = 4.245 \\pm 0.025 GeV\nis found, which yields f_B = 193.4 \\pm 12.3 (OPE) \\pm 4.3 (syst) MeV and\nf_{B_s} = 232.5 \\pm 18.6 (OPE) \\pm 2.4 (syst) MeV.", "category": "hep-ph" }, { "text": "A Consistent Scenario for B to PS Decays: We consider B to PS decays where P stands for pseudoscalar and S for a heavy\n(~1500 MeV) scalar meson. We achieve agreement with available experimental data\n-- which includes a two orders of magnitude hierarchy -- assuming the scalars\nmesons are two quark states. The contribution of the dipolar penguin operator\nO_{11} is quantified.", "category": "hep-ph" }, { "text": "Structure of the sigma meson and the softening: We study the structure of the sigma meson, the lowest-lying resonance of the\npi pi scattering in the scalar-isoscalar channel, through the softening\nphenomena associated with the partial restoration of chiral symmetry. We build\ndynamical chiral models to describe the pi pi scattering amplitude, in which\nthe sigma meson is described either as the chiral partner of the pion or as the\ndynamically generated resonance through the pi pi attraction. It is shown that\nthe internal structure is reflected in the softening phenomena; the softening\npattern of the dynamically generated sigma meson is qualitatively different\nfrom the behavior of the chiral partner of the pion. On the other hand, in the\nsymmetry restoration limit, the dynamically generated sigma meson behaves\nsimilarly to the chiral partner.", "category": "hep-ph" }, { "text": "Search for muon-philic new light gauge boson at Belle II: Motivated by the long-lasting $3.5\\sigma$ discrepancy in the anomalous\nmagnetic moment of muon, we consider a new muon-specific force mediated by a\nlight gauge boson, $X$, with mass $m_X < 2m_\\mu$ and the coupling constant $g_X\n\\sim (10^{-4}, 10^{-3})$. We show that the Belle~II experiment has a robust\nchance to probe such a light boson in $e^+ e^- \\to \\mu^+ \\mu^- + X$ channel and\ncover the most interesting parameter space explaining the discrepancy with the\nplanned target luminosity, $\\int dt \\ {\\cal L}=50~{\\rm ab^{-1}}$. The clean\nsignal of muon-pair plus missing energy at Belle II can be a smoking gun for\nthe new gauge boson. We expect that the (invisibly decaying) muon-philic light\n($m_X \\leq 2 m_\\mu$) gauge boson can be probed down to $g_X \\geq 1.5 \\times\n10^{-4} \\ (4.6 \\times 10^{-4}, \\ 2.3 \\times 10^{-4})$ for 50 (1, 10)\nab${}^{-1}$ search.", "category": "hep-ph" }, { "text": "Selected Topics in Rapidity Gap Physics: This talk will review selected topics in rapidity gap physics. In particular\nI will discuss diffractive jet production and the possibility of searching for\nthe higgs boson using diffraction at the LHC; the dipole picture of diffraction\nand saturation; and those processes where a large momentum is transferred\nacross the rapidity gap, for which there has been recent progress both\nexperimentally and theoretically.", "category": "hep-ph" }, { "text": "On the Higher Moments of Particle Multiplicity, Chemical Freeze-Out and\n QCD Critical Endpoint: We calculate the first six non-normalized moments of particle multiplicity\nwithin the framework of the hadron resonance gas model. In terms of the lower\norder moments and corresponding correlation functions, general expressions of\nhigher order moments are derived. Thermal evolution of the first four\nnormalized moments and their products (ratios) are studied at different\nchemical potentials {\\mu}, so that it is possible to evaluate them at chemical\nfreeze out curve. It is found that a non-monotonic behavior, reflecting the\ndynamical fluctuation and strong correlation of particles starts to appear from\nthe normalized third order moment. We introduce novel conditions for describing\nthe chemical freeze out curve. Although the hadron resonance gas model does not\ncontain any information on the criticality related to the chiral dynamics and\nsingularity in some physical observables, we are able find out the location of\nthe QCD critical endpoint at $\\mu\\sim 350 $MeV and temperature $T \\sim 162\n$MeV.", "category": "hep-ph" }, { "text": "TMD evolution of the Sivers asymmetry: The energy scale dependence of the Sivers asymmetry in semi-inclusive deep\ninelastic scattering is studied numerically within the framework of TMD\nfactorization that was put forward in 2011. The comparison to previous results\nin the literature shows that the treatment of next-to-leading logarithmic\neffects is important for the fall-off of the Sivers asymmetry with energy in\nthe measurable regime. The TMD factorization based approach indicates that the\npeak of the Sivers asymmetry falls off with energy scale Q to good\napproximation as 1/Q^{0.7}, somewhat faster than found previously based on the\nfirst TMD factorization expressions by Collins and Soper in 1981. It is found\nthat the peak of the asymmetry moves rather slowly towards higher transverse\nmomentum values as $Q$ increases, which may be due to the absence of\nperturbative tails of the TMDs in the presented treatments. We conclude that\nthe behavior of the peak of the asymmetry as a function of energy {\\it and}\ntransverse momentum allows for valuable tests of the TMD formalism and the\nconsidered approximations. To confront the TMD approach with experiment, high\nenergy experimental data from an Electron-Ion Collider is required.", "category": "hep-ph" }, { "text": "Mass and CKM Matrices of Quarks and Leptons, the Leptonic CP-phase in\n neutrino oscillations: A general approach for construction of quark and lepton mass matrices is\nformulated. The hierarchy of quarks and charged leptons (\"electrons\") is large,\nit leads using the experimental values of mixing angles to the hierarchical\nmass matrix slightly deviating from one's suggested earlier by Stech and\nincluding naturally the CP-phase.\n The same method based on the rotation of generation numbers in the diagonal\nmass matrix is used in the electron-neutrino sector of theory, where neutrino\nmass matrix is determined by the Majorano see-saw approach. The hierarchy of\nneutrino masses, much smaller than for quarks, was used including all existing\n(even preliminary) experimental data on neutrinos mixing.\n The leptonic mass matrix found in this way includes not known value of the\nleptonic CP-phase. It leads to a large $\\nu_\\mu \\nu_\\tau$ oscillations and\nsuppresses the $\\nu_e\\nu_\\tau$ and also $\\nu_e \\nu_\\mu$ oscillations. The\nexplicit expressions for the probabilities of neutrino oscillation were\nobtained in order to specify the role of leptonic CP-phase. The value of time\nreversal effect (proportional to $\\sin\\delta'$) was found to be small $\\sim\n1%$. However, a dependence of the values of $\\nu_e \\nu_\\mu, \\nu_e \\nu_\\tau$\ntransition probabilities, averaged over oscillations, on the leptonic CP-phase\nhas found to be not small - of order of tens percent.", "category": "hep-ph" }, { "text": "Ratios of Fluctuation Observables in the Search for the QCD Critical\n Point: The QCD critical point can be found in heavy ion collision experiments via\nthe non-monotonic behavior of many fluctuation observables as a function of the\ncollision energy. The event-by-event fluctuations of various particle\nmultiplicities are enhanced in those collisions that freeze out near the\ncritical point. Higher, non-Gaussian, moments of the event-by-event\ndistributions of such observables are particularly sensitive to critical\nfluctuations, since their magnitude depends on the critical correlation length\nto a high power. We present quantitative estimates of the contribution of\ncritical fluctuations to the third and fourth moments of the pion and proton,\nas well as estimates of various measures of pion-proton correlations, all as a\nfunction of the same five non-universal parameters. We show how to use\nnontrivial but parameter independent ratios among these more than a dozen\nfluctuation observables to discover the critical point. We also construct\nratios that, if the critical point is found, can be used to overconstrain the\nvalues of the non-universal parameters.", "category": "hep-ph" }, { "text": "Probing feebly interacting dark matter with monojet searches: Dark matter may consist of feebly interacting massive particles (FIMPs) that\nnever thermalized with the cosmic plasma. Their relic density is achieved via\nfreeze-in for a wide range of masses, significantly expanding the model space\nthat can be tested compared to other production mechanisms. However, testing\nthe tiny couplings required by freeze-in is challenging. We show that FIMPs can\nbe probed by LHC searches for new physics in mono-jet events with large missing\nenergy. We study a $Z'$ portal model in which gluon annihilation produces FIMPs\nin the early universe and today at colliders. Monojet searches by LHC Run 3\nmight discover new physics accounted for by FIMPs with mass in the MeV-TeV\nrange.", "category": "hep-ph" }, { "text": "Pentaquark Magnetic Moments In Different Models: We calculate the magnetic moments of the pentaquark states from different\nmodels and compare our results with predictions of other groups.", "category": "hep-ph" }, { "text": "Fermion dispersion in axion medium: The interaction of a fermion with the dense axion medium is investigated for\nthe purpose of finding an axion medium effect on the fermion dispersion. It is\nshown that axion medium influence on the fermion dispersion under astrophysical\nconditions is negligible small if the correct Lagrangian of the axion-fermion\ninteraction is used.", "category": "hep-ph" }, { "text": "Cerenkov radiation by neutrinos in a supernova core: Neutrinos with a magnetic dipole moment propagating in a medium with a\nvelocity larger than the phase velocity of light emit photons by the Cerenkov\nprocess. The Cerenkov radiation is a helicity flip process via which a\nleft-handed neutrino in a supernova core may change into a sterile right-handed\none and free-stream out of the core. Assuming that the luminosity of such\nsterile right-handed neutrinos is less than $10^{53}$ ergs/sec gives an upper\nbound on the neutrino magnetic dipole moment $\\mu_\\nu < 0.2 \\times 10^{-13}\n\\mu_B$. This is two orders of magnitude more stringent than the previously\nestablished bounds on $\\mu_\\nu$ from considerations of supernova cooling rate\nby right-handed neutrinos.", "category": "hep-ph" }, { "text": "The same-sign top probe for baryon number violation at the LHC: Despite strong experimental evidences for their conservation at low energies,\nthe baryon $B$ and lepton $L$ numbers are not expected to be absolute\nsymmetries. Already violated in the Standard Model (SM) by non-perturbative\neffects (tiny at low temperatures and energies) and not justified by any\nfundamental principle, $B$ and $L$ appear naturally violated in beyond the\nStandard Model (BSM) scenarios, e.g. in supersymmetry (SUSY). The fact that any\nviolation remained unobserved at low energies can nonetheless be explained,\nwithout pushing the associated characteristic sale beyond the TeV, by using SM\nflavour symmetries implemented BSM thanks to the Minimal Flavour Violation\n(MFV) prescription. Violation effects could therefore be observable at the LHC.\nSame-sign (anti-)tops, sometimes leading to a distinctive predominance of\nnegatively charged lepton pairs over positively charged ones, is a clean\nsignature that is for instance generically present in R-parity violating\nsupersymmetry.", "category": "hep-ph" }, { "text": "Sphaleron portal baryogenesis: Nontrivial topological vacua of non-Abelian gauge symmetry $SU(3)\\times\nSU(2)_{L}$ of the Standard Model play an important role in baryogenesis. In\nparticular, the baryon (and lepton) number violation from $SU(2)_{L}$ sphaleron\nis a crucial ingredient for baryogenesis at weak scale or higher. In this work,\nwe point out that generically, a baryon asymmetry is induced by an asymmetry\ngenerated in the new sector through strong $SU(3)$ and/or weak $SU(2)_{L}$\nsphaleron portals and vice versa. In the standard radiation-dominated early\nUniverse, due to phenomenological constraints, the sphaleron portal\nbaryogenesis has to take place at cosmic temperature $T\\gtrsim10^{6}-10^{8}$\nGeV together with a $(B-L)$-violating source. As an example, we show an\nexplicit model where strong sphaleron portal baryogenesis occurs at the scale\nof Peccei-Quinn breaking to solve the strong CP problem and this coincides\nnicely with the scale where the Weinberg operator responsible for Majorana\nneutrino mass is in equilibrium.", "category": "hep-ph" }, { "text": "Flavor Changing Supersymmetry Interactions in a Supernova: We consider for the first time R-parity violating interactions of the Minimal\nStandard Supersymmetric Model involving neutrinos and quarks (``flavor changing\nneutral currents'', FCNC's) in the infall stage of stellar collapse. Our\nconsiderations extend to other kinds of flavor changing neutrino reactions as\nwell. We examine non-forward neutrino scattering processes on heavy nuclei and\nfree nucleons in the supernova core. This investigation has led to four\nprincipal original discoveries/products: (1) first calculation of neutrino\nflavor changing cross sections for spin one half (e.g. free nucleon) and spin\nzero nuclear targets; (2) discovery of nuclear mass number squared (A squared)\ncoherent amplification of neutrino-quark FCNC's; (3) analysis of FCNC-induced\nalteration of electron capture and weak/nuclear equilibrium in the collapsing\ncore; and (4) generalization of the calculated cross sections (mentioned in 1)\nfor the case of hot heavy nuclei to be used in collapse/supernova and neutrino\ntransport simulations. The scattering processes that we consider allow electron\nneutrinos to change flavor during core collapse, thereby opening holes in the\nelectron neutrino sea, which allows electron capture to proceed and results in\na lower core electron fraction. A lower electron fraction implies a lower\nhomologous core mass, a lower shock energy, and a greater nuclear\nphoto-disintegration burden for the shock. In addition, unlike the standard\nsupernova model, the core now could have net muon and/or tau lepton numbers.\nThese effects could be significant even for supersymmetric couplings below\ncurrent experimental bounds.", "category": "hep-ph" }, { "text": "Radiation reaction and limiting acceleration: We investigate the strong acceleration properties of the radiation reaction\nforce and identify a new and promising limiting acceleration feature in the\nEliezer-Ford-O'Connell model; in the strong field regime, for many field\nconfigurations, we find an upper limit to acceleration resulting in a bound to\nthe rate of radiation emission. If this model applies, strongly accelerated\nparticles are losing energy at a much slower pace than predicted by the usual\nradiation reaction benchmark, the Landau-Lifshitz equation, which certainly\ncannot be used in this regime. We explore examples involving various \"constant\"\nelectromagnetic field configurations and study particle motion in a light plane\nwave as well as in a material medium.", "category": "hep-ph" }, { "text": "Comment on \"Chiral symmetry and the intrinsic structure of the nucleon\"-\n by D.B.Leinweber,A.W.Thomas and R.D.Young: Some remarks are presented on a recent paper (Leinweber,Thomas and Young,\nPhys.Rev.Lett. 86, 5011, 2001). In particular a statement of the above paper on\nthe fact that the ratio between the magnetic moments of proton and neutron\nshould remain constant at -3/2, independent of the change of the quark mass is\ndiscussed on the basis of the general parameterization.", "category": "hep-ph" }, { "text": "Supersymmetric Models in Light of Improved Higgs Mass Calculations: We discuss the parameter spaces of supersymmetry (SUSY) scenarios taking into\naccount the improved Higgs-mass prediction provided by FeynHiggs 2.14.1. Among\nother improvements, this prediction incorporates three-loop\nrenormalization-group effects and two-loop threshold corrections, and can\naccommodate three separate mass scales: m_{\\tilde q} (for squarks), m_{\\tilde\ng} (for gluinos) and m_{\\tilde\\chi} (for electroweakinos). Furthermore, it\ncontains an improved treatment of the DRbar scalar top parameters avoiding\nproblems with the conversion to on-shell parameters, that yields more accurate\nresults for large SUSY-breaking scales. We first consider the CMSSM, in which\nthe soft SUSY-breaking parameters m_0 and m_{1/2} are universal at the GUT\nscale, and then sub-GUT models in which universality is imposed at some lower\nscale. In both cases, we consider the constraints from the Higgs-boson mass M_h\nin the bulk of the (m_0, m_{1/2}) plane and also along stop coannihilation\nstrips where sparticle masses may extend into the multi-TeV range. We then\nconsider the minimal anomaly-mediated SUSY-breaking (mAMSB) scenario, in which\nlarge sparticle masses are generic. In all these scenarios the substantial\nimprovements between the calculations of M_h in FeynHiggs 2.14.1 and FeynHiggs\n2.10.0, which was used in an earlier study, change significantly the preferred\nportions of the models' parameter spaces. Finally, we consider the pMSSM11, in\nwhich sparticle masses may be significantly smaller and we find only small\nchanges in the preferred regions of parameter space.", "category": "hep-ph" }, { "text": "The Suppression of Neutralino Annihilation into Zh: The Indirect Detection of neutralino Dark Matter is most promising through\nannihilation channels producing a hard energy spectrum for the detected\nparticles, such as the neutralino annihilation into $Zh$. A cancellation\nhowever makes this particular annihilation channel generically subdominant in\nthe huge parameter space of supersymmetric models. This cancellation requires\nnon-trivial relations between neutralino mixings and masses, which we derive\nfrom gauge independence and unitarity of the MSSM. To show how the cancellation\novershoots leaving only a subdominant result, we use a perturbative expansion\nin powers of the electroweak/supersymmetry breaking ratio $m_{Z}/m_{\\chi}$.", "category": "hep-ph" }, { "text": "The rare decays of D mesons: The flavor changing transitions in the c->u gamma, c->u gamma gamma and c->u\nl+ l- offer the possibility to search for new physics in the charm sector. We\ninvestigate dominant decay mechanisms in the radiative decays D->V gamma,\nD->P(V) l+ l-, D->gamma gamma and we discuss chances to see physics beyond the\nstandard model in these decays. In addition, we analyze Cabibbo allowed D->K pi\ngamma decays with nonresonant K pi, and we probe the role of light vector\nmesons in these decays.", "category": "hep-ph" }, { "text": "The high-energy radiation pattern from BFKLex with double-log collinear\n contributions: We study high-energy jet production in the multi-Regge limit making use of\nthe Monte Carlo event generator BFKLex which includes collinear improvements in\nthe form of double-log contributions as presented in [1]. Making use of the\nanti-kt jet algorithm in the FastJet implementation, we present results for the\naverage transverse momentum and azimuthal angle of the produced jets when two\ntagged forward/backward jets are present in the final state. We also introduce\na new observable which accounts for the average rapidity separation among\nsubsequent emissions. Results are presented, for comparison, at leading order\nand next-to-leading order, with the resummation of collinear double logs\nproposed in [2].", "category": "hep-ph" }, { "text": "Charmless hadronic $B_c \\to VA, AA$ decays in the perturbative QCD\n approach: In this work, we calculate the branching ratios (BRs) and the polarization\nfractions of sixty two charmless two-body $B_c$ meson decays into final states\ninvolving one vector and one axial-vector meson ($VA$) or two axial-vector\nmesons($AA$) within the framework of perturbative QCD (pQCD) approach\nsystematically, where $A$ is either a $^3P_1$ or $^1P_1$ axial-vector meson.\nAll considered decay channels can only occur through the annihilation\ntopologies in the standard model. Based on the perturbative calculations and\nphenomenological analysis, we find the following results: (i) the CP-averaged\nBRs of the considered sixty two $B_c$ decays are in the range of $10^{-5}$ to\n$10^{-9}$; (ii) since the behavior for $^1P_1$ meson is much different from\nthat of $^3P_1$ meson, the BRs of $B_c \\to A(^1P_1) (V, A(^1P_1))$ decays are\ngenerally larger than that of $B_c \\to A(^3P_1) (V, A(^3P_1))$ decays in the\npQCD approach; (iii) many considered decays modes, such as $B_c\\to a_1(1260)^+\n\\omega$, $b_1(1235) \\rho$, etc, have sizable BRs within the reach of the LHCb\nexperiments; (iv) the longitudinal polarization fractions of most considered\ndecays are large and play the dominant role; (v) the pQCD predictions for\nseveral decays involving mixtures of $^3P_1$ and/or $^1P_1$ mesons are highly\nsensitive to the values of the mixing angles, which will be tested by the\nongoing LHC and forthcoming Super-B experiments; (vi) the CP-violating\nasymmetries of these considered $B_c$ decays are absent in the standard model\nbecause only one type tree operator is involved.", "category": "hep-ph" }, { "text": "Shooting String Holography of Jet Quenching at RHIC and LHC: We derive a new formula for jet energy loss using finite endpoint momentum\nshooting strings initial conditions in SYM plasmas to overcome the difficulties\nof previous falling string holographic scenarios. We apply the new formula to\ncompute the nuclear modification factor RAA and the elliptic flow parameter v2\nof light hadrons at RHIC and LHC. We show furthermore that Gauss-Bonnet\nquadratic curvature corrections to the AdS5 geometry improve the agreement with\nthe recent data.", "category": "hep-ph" }, { "text": "Non-linear evolution in QCD at high-energy beyond leading order: The next-to-leading order (NLO) Balitsky-Kovchegov (BK) equation describing\nthe high-energy evolution of the scattering between a dilute projectile and a\ndense target suffers from instabilities unless it is supplemented by a proper\nresummation of the radiative corrections enhanced by (anti-)collinear\nlogarithms. Earlier studies have shown that if one expresses the evolution in\nterms of the rapidity of the dilute projectile, the dominant anti-collinear\ncontributions can be resummed to all orders. However, in applications to\nphysics, the results must be re-expressed in terms of the rapidity of the dense\ntarget. We show that although they lead to stable evolution equations,\nresummations expressed in the rapidity of the dilute projectile show a strong,\nunwanted, scheme dependence when their results are translated in terms of the\ntarget rapidity. Instead, in this paper, we work directly in the rapidity of\nthe dense target where anti-collinear contributions are absent but where new,\ncollinear, instabilities arise. These are milder since disfavoured by the\ntypical BK evolution. We propose several prescriptions for resumming these new\ndouble logarithms and find only little scheme dependence. The resummed\nequations are non-local in rapidity and can be extended to full NLO accuracy.", "category": "hep-ph" }, { "text": "Branching Fractions and Direct CP Violation in Charmless Three-body\n Decays of B Mesons: Charmless three-body decays of B mesons is studied using a simple model based\non the framework of the factorization approach. Hadronic three-body decays\nreceive both resonant and nonresonant contributions. Dominant nonresonant\ncontributions to tree-dominated three-body decays arise from the $b\\to u$ tree\ntransition which can be evaluated using heavy meson chiral perturbation theory\nvalid in the soft meson limit. For penguin-dominated decays, nonresonant\nsignals come mainly from the penguin amplitude governed by the matrix elements\nof scalar densities $$. We use the measurements of $\\bar\nB^0\\to K_SK_SK_S$ to constrain the nonresonant component of $$. The intermediate vector meson contributions to three-body decays are\nidentified through the vector current, while the scalar meson resonances are\nmainly associated with the scalar density. While the calculated direct CP\nviolation in $B^-\\to K^+K^-K^-$ and $B^-\\to \\pi^+\\pi^-\\pi^-$ decays agrees well\nwith experiment in both magnitude and sign, the predicted CP asymmetries in\n$B^-\\to \\pi^- K^+K^-$ and $B^-\\to K^-\\pi^+\\pi^-$ are wrong in signs when\nconfronted with experiment. It has been conjectured recently that a possible\nresolution to this CP puzzle may rely on final-state rescattering of\n$\\pi^+\\pi^-$ and $K^+K^-$. Assuming a large strong phase associated with the\nmatrix element $$ arising from some sort of power corrections,\nwe fit it to the data of $K^-\\pi^+\\pi^-$ and find a correct sign for $\\pi^-\nK^+K^-$.", "category": "hep-ph" }, { "text": "A Three-Flavor Chiral Effective Model with Four Baryonic Multiplets\n within the Mirror Assignment: In the case of three quark flavors, (pseudo)scalar diquarks transform as\nantiquarks under chiral transformations. We construct four spin-1/2 baryonic\nmultiplets from left- and right-handed quarks as well as left- and right-handed\ndiquarks. The fact that two of these multiplets transform in a \"mirror\" way\nallows for chirally invariant mass terms. We then embed these baryonic\nmultiplets into the Lagrangian of the so-called extended Linear Sigma Model,\nwhich features (pseudo)scalar and (axial-)vector mesons, as well as glueballs.\nReducing the Lagrangian to the two-flavor case, we obtain four doublets of\nnucleonic states. These mix to produce four experimentally observed states with\ndefinite parity: the positive-parity nucleon $N(939)$ and Roper resonance\n$N(1440)$, as well as the negative-parity resonances $N(1535)$ and $N(1650)$.\nWe determine the parameters of the nucleonic part of the Lagrangian from a fit\nto masses and decay properties of the aforementioned states. Studying the limit\nof vanishing quark condensate, we conclude that $N(939)$ and $N(1535)$, as well\nas $N(1440)$ and $N(1650)$ form pairs of chiral partners.", "category": "hep-ph" }, { "text": "Two-loop Calculation of Higgs Mass in Gauge-Higgs Unification: 5D\n Massless QED Compactified on S^1: We calculate the quantum corrections to the mass of the zero mode of the\nfifth component of the gauge field at two-loop level in a five dimensional\nmassless QED compactified on S^1. We discuss in detail how the divergences are\nexactly canceled and the mass becomes finite. The key ingredients to obtain the\nresult are the five dimensional gauge invariance and the Ward-Takahashi\nidentity. We also evaluate the finite part of corrections.", "category": "hep-ph" }, { "text": "Baryon deceleration by strong chromofields in ultrarelativistic nuclear\n collisions: It is assumed that strong chromofields are generated at early stages of\nultrarelativistic heavy-ion collisions which give rise to a collective\ndeceleration of net baryons from colliding nuclei. We have solved classical\nequations of motion for baryonic slabs under the action of a time-dependent\nlongitudinal chromoelectric field. It is demonstrated that the slab final\nrapidities are rather sensitive to the strength and decay time of the\nchromofield as well as to the back reaction of the produced partonic plasma.\nThe net-baryon rapidity loss of about 2 units, found for most central Au-Au\ncollisions at RHIC, can be explained by the action of chromofields with the\ninitial energy density of about 50 GeV/fm^3. Predictions for the baryon\nstopping at the LHC are made.", "category": "hep-ph" }, { "text": "LHC diboson excesses as an evidence for a heavy WW resonance: Recently reported diboson excesses at LHC are interpreted to be connected\nwith heavy $WW$ resonance with weak isotopic spin 2. The resonance appears due\nto the wouldbe anomalous triple interaction of the weak bosons, which is\ndefined by well-known coupling constant $\\lambda$. We obtain estimates for the\neffect, which qualitatively agree with ATLAS data. Effects are predicted in\ninclusive production of $W^+W^+, W^+ (Z,\\gamma), W^+ W^-, (Z,\\gamma)\n(Z,\\gamma), W^- (Z,\\gamma), W^-W^-$ resonances with $M_R \\simeq 2\\,TeV$, which\ncould be reliably checked at the upgraded LHC with $\\sqrt{s}\\,=\\,13 TeV$. In\nthe framework of an approach to the spontaneous generation of of the triple\nanomalous interaction its coupling constant is estimated to be $\\lambda =\n-\\,0.017\\pm 0.005$ in an agreement with existing restrictions.", "category": "hep-ph" }, { "text": "Anomalous Gauge Interactions of the Higgs Boson: Precision Constraints\n and Weak Boson Scatterings: Interaction of Higgs scalar (H) with weak gauge bosons (V=W,Z) is the {\\it\nkey} to understand electroweak symmetry breaking (EWSB) mechanism. New physics\neffects in the HVV interactions, as predicted by models of compositeness,\nsupersymmetry and extra dimensions, can be formulated as anomalous couplings\nvia a generic effective Lagrangian. We first show that the existing electroweak\nprecision data already impose nontrivial indirect constraints on the anomalous\nHVV couplings. Then, we systematically study VV --> VV scatterings in the TeV\nregion, via Gold-plated pure leptonic decay modes of the weak bosons. We\ndemonstrate that, even for a light Higgs boson in the mass range 115GeV < m_H <\n300GeV, this process can directly probe the anomalous HVV interactions at the\nLHC with an integrated luminosity of 300fb^{-1}, which further supports the\n``No-Lose'' theorem for the LHC to uncover the EWSB mechanism. Comparisons with\nthe constraints from measuring the cross section of VH associate production and\nthe Higgs boson decay width are also given.", "category": "hep-ph" }, { "text": "WPHACT 1.0 - A program for $WW$, Higgs and 4 fermion physics at $e^+\n e^-$ colliders: WPHACT (W W and Higgs Physics with PHACT) is a MC program and unweighted\nevent generator which computes all Standard Model processes with four fermion\nin the final state at $e^+ e^-$ colliders. It is based on an helicity amplitude\nmethod which allows precise and fast evaluations of the matrix elements both\nfor massless and massive fermions. Fermion masses for $b$ quarks are exactly\ntaken into account. QED initial state and Coulomb corrections are evaluated,\nwhile QCD final state corrections are included in an approximate formulation.\nCuts can be easily introduced and distributions for any variable at parton\nlevel can be implemented. The contributions to the processes of neutral\nStandard Model or Susy Higgs can be included. Anomalous couplings effects for\nthe triple coupling can be computed. An interface to hadronization is provided\nand Jetset can be directly called from the program.", "category": "hep-ph" }, { "text": "Light mesons production at the Tevatron to next-to-leading order: Inclusive production of light mesons ($\\pi^0$, $\\eta$, $\\pi^{\\pm}$, $K^{\\pm}$\n) at the Tevatron is considered in QCD to next-to-leading order in the\nformalism of fragmentation functions. We present various distributions of\nphenomenological interest, along with a new set of $K$ mesons fragmentation\nfunctions.", "category": "hep-ph" }, { "text": "Improving the Effective Potential, Multi-Mass Problem and Modified\n Mass-Dependent Scheme: We present a new procedure for improving the effective potential by using\nrenormalization group equation (RGE) in the presence of several mass scales. We\npropose a modification of the mass-dependent (MD) renormalization scheme, MDbar\nscheme, so that the scalar mass parameter runs at most logarithmically on the\none hand and the decoupling of heavy particles is naturally incorporated in the\nRGE's on the other. Thanks to these properties, the procedure in MDbar scheme\nturns out to be very simple compared with the regionwise procedure in MSbar\nscheme proposed previously. The relation with other schemes is also discussed\nboth analytically and numerically.", "category": "hep-ph" }, { "text": "A quark model analysis of the Sivers function: We develop a formalism to evaluate the Sivers function. The approach is well\nsuited for calculations which use constituent quark models to describe the\nstructure of the nucleon. A non-relativistic reduction of the scheme is\nperformed and applied to the Isgur-Karl model of hadron structure. The results\nobtained are consistent with a sizable Sivers effect and the signs for the u\nand d flavor contributions turn out to be opposite. This pattern is in\nagreement with the one found analyzing, in the same model, the impact parameter\ndependent generalized parton distributions. The Burkardt Sum Rule turns out to\nbe fulfilled to a large extent. We estimate the QCD evolution of our results\nfrom the momentum scale of the model to the experimental one and obtain\nreasonable agreement with the available data.", "category": "hep-ph" }, { "text": "Searching for Ultralight Dark Matter Conversion in Solar Corona using\n Low Frequency Array Data: Ultralight dark photons and axions are well-motivated hypothetical dark\nmatter candidates. Both dark photon dark matter and axion dark matter can\nresonantly convert into electromagnetic waves in the solar corona when their\nmass is equal to the solar plasma frequency. The resultant electromagnetic\nwaves appear as monochromatic signals within the radio-frequency range with an\nenergy equal to the dark matter mass, which can be detected via radio\ntelescopes for solar observations. Here we show our search for converted\nmonochromatic signals in the observational data collected by the\nhigh-sensitivity Low Frequency Array (LOFAR) telescope and establish an upper\nlimit on the kinetic mixing coupling between dark photon dark matter and\nphoton, which can reach values as low as $10^{-13}$ within the frequency range\nof $30-80$ MHz. This limit represents an improvement of approximately one order\nof magnitude better than the existing constraint from the cosmic microwave\nbackground observation. Additionally, we derive an upper limit on the\naxion-photon coupling within the same frequency range, which is better than the\nconstraints from Light-Shining-through-a-Wall experiments while not exceeding\nthe CERN Axion Solar Telescope (CAST) experiment or other astrophysical bounds.", "category": "hep-ph" }, { "text": "Production of Isolated Photons in Deep Inelastic Scattering: We present here the predictions obtained from a calculation of the inclusive\nisolated photon production cross section in deep inelastic scattering. The\nresults are compared with the cross section measurement of the ZEUS\ncollaboration and found in good agreement with all aspects of it. Furthermore,\na way of measuring the quark-to-photon fragmention function in DIS is also\nbriefly outlined.", "category": "hep-ph" }, { "text": "Soft-Wall Stabilization: We propose a general class of five-dimensional soft-wall models with AdS\nmetric near the ultraviolet brane and four-dimensional Poincar\\'e invariance,\nwhere the infrared scale is determined dynamically. A large UV/IR hierarchy can\nbe generated without any fine-tuning, thus solving the electroweak/Planck scale\nhierarchy problem. Generically, the spectrum of fluctuations is discrete with a\nlevel spacing (mass gap) provided by the inverse length of the wall, similar to\nRS1 models with Standard Model fields propagating in the bulk. Moreover two\nparticularly interesting cases arise. They can describe: (a) a theory with a\ncontinuous spectrum above the mass gap which can model unparticles\ncorresponding to operators of a CFT where the conformal symmetry is broken by a\nmass gap, and; (b) a theory with a discrete spectrum provided by linear Regge\ntrajectories as in AdS/QCD models.", "category": "hep-ph" }, { "text": "A model of non-perturbative gluon emission in an initial state parton\n shower: We consider a model of transverse momentum production in which\nnon-perturbative smearing takes place throughout the perturbative evolution, by\na simple modification to an initial state parton shower algorithm. Using this\nas the important non-perturbative ingredient, we get a good fit to data over a\nwide range of energy. Combining it with the non-perturbative masses and cutoffs\nthat are a feature of conventional parton showers also leads to a reasonable\nfit. We discuss the extrapolation to the LHC.", "category": "hep-ph" }, { "text": "CP violation in $B \\to \u03c6K$ decay and anomalous right-handed top\n quark couplings: We explore the CP violation in $B \\to \\phi K$ decay processes in the presence\nof the anomalous right-handed $\\bar{t}sW$ and $\\bar{t}bW$ couplings. The\ncomplex anomalous top coupling can be a source of the new CP violation and lead\nto a deviation of the observed weak phase in $B \\to \\phi K$ decays, which takes\naccount for the present disagreement of the observed $\\sin 2 \\beta$ between $B\n\\to J/\\psi K$ and $B \\to \\phi K$ decays. The direct CP violation is also\npredicted.", "category": "hep-ph" }, { "text": "Analyticity Properties and Unitarity Constraints of Heavy Meson Form\n Factors: We derive new bounds on the b-number form factor $F(q^2)$ of the B meson.\n(Revised version of hep-ph/9306214).", "category": "hep-ph" }, { "text": "Impact of axions on the Cassiopea A neutron star cooling: The observed anomalous steady decrease in surface temperature of the\nsupernova remnant Cassiopeia A (Cas A), which was reported about ten years ago,\nhas generated much debate. Several exotic cooling scenarios have been proposed\nusing non-standard assumptions about the physics and evolution of this neutron\nstar (NS). At present, significant corrections have been made to the\nobservational data, which make it possible to numerically simulate the Cas A NS\ncooling process in the framework of the scenario of minimal neutrino cooling.\nIf there is an additional source of cooling, such as axion emission, the\nsteepness of the Cas A NS surface temperature drop will increase with the\ngrowth of the axion-nucleon interaction strength. This makes it possible to\nlimit the minimum value of the axion decay constant $f_a$ using the condition\nthat the NS surface temperature should be within the 99% confidence interval\nobtained from the observational data. Two types of axion models are considered:\nthe Kim-Shifman-Weinstein-Zakharov -- KSVZ model and the\nDean-Fischler-Srednitsky-Zhitnitsky --DFSZ model. The above criterion gives a\nlower limit on the axion decay constant, $f_a>3\\times 10^7$ GeV and\n$f_a>4.5\\times 10^8$ GeV for KSVZ and DFSZ axions, respectively.", "category": "hep-ph" }, { "text": "Effective theories with maximal analyticity: In this paper (second in the series) we study the properties of tree-level\nbinary amplitudes of the infinite-component effective field theory of strong\ninteraction obeying the requirements of quark-hadron duality and maximal\nanalyticity. In contrast to the previous paper, here we derive the results\nfollowing from less restrictive --- Regge-like --- boundedness conditions. We\ndevelop the technique of Cauchy's forms in two variables and show the\nstring-like structure of a theory. Next, we derive the full set of bootstrap\nconstraints for the resonance parameters in (\\pi,K) system. Numerical test\nshows: (1) those constraints are consistent with data on well established\nvector resonances; (2) two light broad resonances -- sigma- and kappa-mesons --\nare needed to saturate sum rules following from Chiral symmetry and\nanalyticity. As a by-product we obtain expressions for the parameters of Chiral\nexpansions and give corresponding estimates.", "category": "hep-ph" }, { "text": "Color transparency in deeply inelastic diffraction: We suggest a simple physical picture for the diffractive parton distributions\nthat appear in diffractive deeply inelastic scattering. In this picture,\npartons impinging on the proton can have any transverse separation, but only\nwhen the separation is small can they penetrate the proton without breaking it\nup. By comparing the predictions from this picture with the diffractive data\nfrom HERA, we determine rough values for the small separations that dominate\nthe diffraction process.", "category": "hep-ph" }, { "text": "A $L_\u03bc- L_\u03c4$ theory of Higgs flavor violation and $(g-2)_\u03bc$: Several experiments reported hints for the violation of lepton flavor or\nlepton flavor universality in processes involving muons. Most prominently,\nthere is the hint for a non-zero rate of the flavor violating Higgs decay $h\n\\to \\tau\\mu$ at the LHC, as well as the hint for lepton flavor universality\nviolation in rare $B$ meson decays at LHCb. In addition, also the long standing\ndiscrepancy in the anomalous magnetic moment of the muon motivates new physics\nconnected to muons. A symmetry which violates lepton flavor universality, is\n$L_\\mu-L_\\tau$: the difference of muon-number and tau-number. We show that\nadding vector-like fermions to a $L_\\mu-L_\\tau$ theory generates naturally an\neffect in the anomalous magnetic moment of the muon and $h\\to\\tau\\mu$, while\neffects in other $\\tau \\to \\mu$ transitions are systematically suppressed by\nsymmetry arguments. We find that if $L_\\mu-L_\\tau$ is gauged it is possible to\nalso accommodate the discrepant $b\\to s\\mu\\mu$ data while predicting a\n$\\tau\\to3\\mu$ and a modified $h\\to\\mu\\mu$ rate within reach of upcoming\nexperiments.", "category": "hep-ph" }, { "text": "Probing new physics with high-multiplicity events: UHE neutrinos at\n air-shower detector arrays: Semi-classical processes such as production and decay of electroweak\nsphaleron in the Standard Model and also microscopic black hole in low scale\ngravity scenario typically involve large number of particles in final states.\nThese large multiplicities can be distinctively seen in collisions of\nUltra-high-energy (UHE) neutrinos with $E_\\nu \\geq 10^9~\\text{GeV}$ and\nnucleons in the atmosphere of the Earth. Focusing on air-shower detector array\nexperiments including Telescope Array Experiment (TA), Pierre-Auger Observatory\n(Auger), we propose strategic ways to discover and analyze such events.", "category": "hep-ph" }, { "text": "The non-perturbative constraint on sea quarks --the strange sea quarks\n in the nucleon and the soft pion contribution at high energy--: The mean charge sum rule for the light sea quarks in the nucleon which holds\nunder the same theoretical footing as the modified Gottfried sum rule shows\nthat a usual parameterization of the strange sea quark distribution\nunderestimate its contribution in the small $x$ region. We give a discussion of\nthe soft pion contribution at high energy as a possible explanation of the\nsaturation of the sum rule and show that it naturally explains why the strange\nsea quark is suppressed in the region above $x \\sim 0.01$ while it becomes\nabundant below it.", "category": "hep-ph" }, { "text": "Minimal gauge inflation: We consider a gauge inflation model in the simplest orbifold M4 x S1/Z2 with\nthe minimal non-Abelian SU(2) hidden sector gauge symmetry. The inflaton\npotential is fully radiatively generated solely by gauge self-interactions.\nFollowing the virtue of gauge inflation idea, the inflaton, a part of the five\ndimensional gauge boson, is automatically protected by the gauge symmetry and\nits potential is stable against quantum corrections. We show that the model\nperfectly fits the recent cosmological observations, including the recent WMAP\n5-year data, in a wide range of the model parameters. In the perturbative\nregime of gauge interactions (g_{4D} <= 1/(2pi R M_P)) with the moderately\ncompactified radius (10 <= R M_P <= 100) the anticipated magnitude of the\ncurvature perturbation power spectrum and the value of the corresponding\nspectral index are in perfect agreement with the recent observations. The model\nalso predicts a large fraction of the gravitational waves, negligible\nnon-Gaussianity, and high enough reheating temperature.", "category": "hep-ph" }, { "text": "Separate seesaw and its applications to dark matter and baryogenesis: We propose a new seesaw model in an extra-dimensional setup where only\nright-handed neutrinos are bulk fields. In the model, localizations of an\nextra-dimensional wave function and brane Majorana mass of the right-handed\nneutrinos can be different among each generation of the right-handed neutrinos.\nThe setup can lead to different suppression factor dependences of effective\nright-handed neutrino masses and neutrino Yukawa couplings for each generation.\nIt is shown that the resultant mass spectra of the right-handed neutrinos and\nneutrino Yukawa couplings are favored in models of neutrino dark matter with\nbaryogenesis.", "category": "hep-ph" }, { "text": "Heavy baryon spectroscopy: Masses of heavy baryons are calculated in the relativistic quark-diquark\npicture. Obtained results are in good agreement with available experimental\ndata including recent measurements by the LHCb Collaboration. Possible quantum\nnumbers of excited heavy baryon states are discussed.", "category": "hep-ph" }, { "text": "Analytic Study of Small Scale Structure on Cosmic Strings: The properties of string networks at scales well below the horizon are poorly\nunderstood, but they enter critically into many observables. We argue that in\nsome regimes, stretching will be the only relevant process governing the\nevolution. In this case, the string two-point function is determined up to\nnormalization: the fractal dimension approaches one at short distance, but the\nrate of approach is characterized by an exponent that plays an essential role\nin network properties. The smoothness at short distance implies, for example,\nthat cosmic string lensing images are little distorted. We then add in loop\nproduction as a perturbation and find that it diverges at small scales. This\nneed not invalidate the stretching model, since the loop production occurs in\nlocalized regions, but it implies a complicated fragmentation process. Our\nability to model this process is limited, but we argue that loop production\npeaks a few orders of magnitude below the horizon scale, without the inclusion\nof gravitational radiation. We find agreement with some features of\nsimulations, and interesting discrepancies that must be resolved by future\nwork.", "category": "hep-ph" }, { "text": "Exclusive hadronic tau decays as probes of non-SM interactions: We perform a global analysis of exclusive hadronic tau decays into one and\ntwo mesons using the low-energy limit of the Standard Model Effective Field\nTheory up to dimension six, assuming left-handed neutrinos. A controlled\ntheoretical input on the Standard Model hadronic form factors, based on chiral\nsymmetry, dispersion relations, data and asymptotic QCD properties, has allowed\nus to set bounds on the New Physics effective couplings using the present\nexperimental data. Our results highlight the importance of semileptonic $\\tau$\ndecays in complementing the traditional low-energy probes, such nuclear $\\beta$\ndecays or semileptonic pion and kaon decays, and the high-energy measurements\nat LHC scales. This makes yet another reason for considering hadronic tau\ndecays as golden modes at Belle-II.", "category": "hep-ph" }, { "text": "HARD PROBES OF DENSE MATTER: Direct probes for the QGP must be hard enough to resolve sub-hadronic scales\n($\\ll \\la^{-1}$) and distinguish confined and deconfined media. This can be\nachieved by fast colour charges (jets) and heavy quark resonances (quarkonia).\nAfter a general survey, we study quarkonia as confinement probe and show in\nparticular that confined matter is transparent, deconfined matter opaque to\n\\J's.", "category": "hep-ph" }, { "text": "Pauli-Villars Regularization in a Discrete Light-Cone Model: Pauli-Villars regularization is successfully applied to nonperturbative\ncalculations in a (3+1)-dimensional light-cone model. Numerical results\nobtained with discretized light-cone quantization compare favorably with the\nanalytic solution.", "category": "hep-ph" }, { "text": "pi(-)p atom in ChPT: strong energy-level shift: The general formula of the pi(-)p atom strong energy-level shift in the 1s\nstate is derived in the next-to-leading order in the isospin breaking, and in\nall orders in chiral expansion. Isospin-breaking corrections to the level shift\nare explicitly evaluated at order p^2 in ChPT. The results clearly demonstrate\nthe necessity to critically reaccess the values of the piN scattering lengths,\nextracted from the energy-level shift measurement by means of the potential\nmodel-based theoretical analysis.", "category": "hep-ph" }, { "text": "The Inverse Seesaw in Conformal Electro-Weak Symmetry Breaking and\n Phenomenological Consequences: We study the inverse seesaw mechanism for neutrino masses and\nphenomenological consequences in the context of conformal electro-weak symmetry\nbreaking. The main difference to the usual case is that all explicit fermion\nmass terms including Majorana masses for neutrinos are forbidden. All fermion\nmass terms arise therefore from vacuum expectation values of suitable scalars\ntimes some Yukawa couplings. This leads to interesting consequences for model\nbuilding, neutrino mass phenomenology and the Dark Matter abundance. In the\ncontext of the inverse seesaw we find a favoured scenario with heavy\npseudo-Dirac sterile neutrinos at the TeV scale, which in the conformal\nframework conspire with the electro-weak scale to generate keV scale warm Dark\nMatter. The mass scale relations provide naturally the correct relic abundance\ndue to a freeze-in mechanism. We demonstrate also how conformal symmetry\ndecouples the right-handed neutrino mass scale and effective lepton number\nviolation. We find that lepton flavour violating processes can be well within\nthe reach of modern experiments. Furthermore, interesting decay signatures are\nexpected at the LHC.", "category": "hep-ph" }, { "text": "Determination of Fundamental Supersymmetry Parameters from Chargino\n Production at Lepii: If accessible at LEP II, chargino production is likely to be one of the few\navailable supersymmetric signals for many years. We consider the prospects for\nthe determination of fundamental supersymmetry parameters in such a scenario.\nThe study is complicated by the dependence of observables on a large number of\nthese parameters. We propose a straightforward procedure for disentangling\nthese dependences and demonstrate its effectiveness by presenting a number of\ncase studies at representative points in parameter space. Working in the\ncontext of the minimal supersymmetric standard model, we find that chargino\nproduction by itself is a fairly sensitive probe of the supersymmetry-breaking\nsector. For significant regions of parameter space, it is possible to test the\ngaugino mass unification hypothesis and to measure the gaugino contents of the\ncharginos and neutralinos, thereby testing the predictions of grand unification\nand the viability of the lightest supersymmetric particle as a dark matter\ncandidate. For much of the parameter space, it is also possible to set limits\non the mass of the electron sneutrino, which provide a valuable guide for\nfuture particle searches.", "category": "hep-ph" }, { "text": "Perturbative heavy quarkonium spectrum at\n next-to-next-to-next-to-leading order: We compute the energy levels of some of the lower-lying heavy quarkonium\nstates perturbatively up to O(alpha_s^5*m) and O(alpha_s^5*m*log[alpha_s]).\nStability of the predictions depends crucially on the unknown 4-loop pole-MSbar\nmass relation. We discuss the current status of the predictions with respect to\nthe observed bottomonium spectrum.", "category": "hep-ph" }, { "text": "Measuring the skewness dependency of Generalized Parton Distributions: Generalized Parton Distributions (GPDs) have emerged over the 1990s as a\npowerful concept and tool to study nucleon structure. They provide nucleon\ntomography from the correlation between transverse position and longitudinal\nmomentum of partons. The Double Deeply Virtual Compton Scattering (DDVCS)\nprocess consists of the Deeply Virtual Compton Scattering (DVCS) process with a\nvirtual photon in the final state eventually generating a lepton pair, which\ncan be either an electron-positron or a muon-antimuon pair. The virtuality of\nthe final time-like photon can be measured and varied, thus providing an extra\nlever arm and allowing one to measure the GPDs for the initial and transferred\nmomentum dependences independently. This unique feature of DDVCS is of\nrelevance, among others, for the determination of the distribution of nuclear\nforces which is accessed through the skewness dependency of GPDs. This\nproceeding discusses the feasibility and merits of a DDVCS experiment in the\ncontext of JLab 12 GeV based on model-predicted pseudo-data and the capability\nof extraction of Compton Form Factors based on a fitter algorithm.", "category": "hep-ph" }, { "text": "Color flux-tube nature of the states $T_{cs}(2900)$ and\n $T^a_{c\\bar{s}}(2900)$: Inspired by the states $T_{cs0}(2900)^0$, $T_{cs1}(2900)^0$,\n$T^a_{c\\bar{s}0}(2900)^{0}$ and $T^a_{c\\bar{s}0}(2900)^{++}$ reported by the\nLHCb Collaboration, we carry out a systematical investigation on the properties\nof the ground and $P$-wave states $[cs][\\bar{u}\\bar{d}]$ and\n$[cu][\\bar{s}\\bar{d}]$ with various spin, isospin or $U$-spin, and color\ncombinations in a multiquark color flux-tube model. Matching our results with\nthe spin-parity and mass of the states $T_{cs0}(2900)^0$ and $T_{cs1}(2900)^0$,\nwe can describe them as the compact states $[cs][\\bar{u}\\bar{d}]$ with\n$I(J^{P})=1(0^+)$ and $0(1^-)$ in the model, respectively. The ground state\n$T_{cs0}(2900)^0$ is mainly made of strongly overlapped an axial-vector\n$[cs]_{\\bar{\\mathbf{3}}_c}$ and an axial-vector\n$[\\bar{u}\\bar{d}]_{\\mathbf{3}_c}$. The $P$-wave state $T_{cs1}(2900)^0$ is\ndominantly consisted of a gradually separated scalar or axial vector\n$[cs]_{\\bar{\\mathbf{3}}_c}$ and a scalar $[\\bar{u}\\bar{d}]_{\\mathbf{3}_c}$ in\nthe shape of a dumbbell. Supposing the states $T^a_{c\\bar{s}0}(2900)^{0}$ and\n$T^a_{c\\bar{s}0}(2900)^{++}$ belong to the same isospin triplet, the mass of\nthe state $\\left [[cu]_{\\bar{\\mathbf{3}}_c}[\\bar{s}\\bar{d}]_\n{\\mathbf{3}_c}\\right ]_{\\mathbf{1}_c}$ with symmetrical $U$-spin and $J^P=0^+$\nis highly consistent with that of the states $T^a_{c\\bar{s}0}(2900)^{0}$ and\n$T^a_{c\\bar{s}0}(2900)^{++}$ in the model. After coupling two color\nconfigurations, the state $[cu][\\bar{s}\\bar{d}]$ is slightly lighter than the\nstates $T^a_{c\\bar{s}0}(2900)^{0}$ and $T^a_{c\\bar{s}0}(2900)^{++}$. In\naddition, we also discuss the properties of other states in the model.", "category": "hep-ph" }, { "text": "$b\\to s \u03b3$ Decay in the Two Higgs Doublet Model: QCD corrections to $b \\to s \\gamma$ decay in the two Higgs doublet model are\ncalculated from the energy scale of top quark to that of bottom. The\nconstraints on the two Higgs doublet model from the new experimental bounds of\n$b\\to s\\gamma$ by CLEO and the latest top quark mass by CDF and D0 are\nreanalyzed. It shows that the constraints become more stringent than that of\nthe earlier analysis, i.e. a bigger region of the parameter space of the model\nis ruled out.", "category": "hep-ph" }, { "text": "Extra dimensions, orthopositronium decay, and stellar cooling: In a class of extra dimensional models with a warped metric and a single\nbrane the photon can be localized on the brane by gravity only. An intriguing\nfeature of these models is the possibility of the photon escaping into the\nextra dimensions. The search for this effect has motivated the present round of\nprecision orthopositronium decay experiments. We point out that in this\nframework a photon in plasma should be metastable. We consider the\nastrophysical consequences of this observation, in particular, what it implies\nfor the plasmon decay rate in globular cluster stars and for the core-collapse\nsupernova cooling rate. The resulting bounds on the model parameter exceed the\npossible reach of orthopositronium experiments by many orders of magnitude.", "category": "hep-ph" }, { "text": "Effects of random matter density fluctuations on the neutrino\n oscillation transition probabilities in the Earth: In this paper, we investigate the effects of random fluctuations of the Earth\nmatter density for long baselines on the neutrino oscillation transition\nprobabilities. We especially identify relevant parameters characterizing the\nmatter density noise and calculate their effects by averaging over statistical\nensembles of a large number of matter density profiles. For energies and\nbaselines appropriate to neutrino factories, absolute errors on the relevant\nappearance probabilities are at the level of $|\\Delta P_{\\alpha \\beta}| \\sim\n10^{-4}$ (with perhaps $|\\Delta P_{\\mu e}|/P_{\\mu e} \\sim 1%$ for neutrinos),\nwhereby a modest improvement in understanding of the geophysical data should\nrender such effects unimportant.", "category": "hep-ph" }, { "text": "Two-loop corrections to the Higgs trilinear coupling in BSM models with\n classical scale invariance: Classical scale invariance (CSI) is an attractive concept for BSM model\nbuilding, explaining the apparent alignment of the Higgs sector and potentially\nrelating to the hierarchy problem. Furthermore, a particularly interesting\nfeature is that the Higgs trilinear coupling $\\lambda_{hhh}$ is universally\npredicted at one loop in CSI models, and deviates by 67% from its (tree-level)\nSM prediction. This result is however modified at two loops, and we review in\nthese proceedings our calculation of leading two-loop corrections to\n$\\lambda_{hhh}$ in models with classical scale invariance, taking as an example\na CSI scenario of a Two-Higgs-Doublet Model. We find that the inclusion of\ntwo-loop effects allows distinguishing different scenarios with CSI, although\nthe requirement of reproducing the known 125-GeV Higgs-boson mass severely\nrestricts the allowed values of $\\lambda_{hhh}$.", "category": "hep-ph" }, { "text": "Treating the b quark distribution function with reliable uncertainties: The parton distribution function for a b quark in the B meson (called the\nshape function) plays an important role in the analysis of the B -> X_s gamma\nand B -> X_u l nu data, and gives one of the dominant uncertainties in the\ndetermination of |Vub|. We introduce a new framework to treat the shape\nfunction, which consistently incorporates its renormalization group evolution\nand all constraints on its shape and moments in any short distance mass scheme.\nAt the same time it allows a reliable treatment of the uncertainties. We\ndevelop an expansion in a suitable complete set of orthonormal basis functions,\nwhich provides a procedure for systematically controlling the uncertainties due\nto the unknown functional form of the shape function. This is a significant\nimprovement over fits to model functions. Given any model for the shape\nfunction, our construction gives an orthonormal basis in which the model occurs\nas the first term, and corrections to it can be studied. We introduce a new\nshort distance scheme, the \"invisible scheme\", for the kinetic energy matrix\nelement, lambda_1. We obtain closed form results for the differential rates\nthat incorporate perturbative corrections and a summations of logarithms at any\norder in perturbation theory, and present results using known\nnext-to-next-to-leading order expressions. The experimental implementation of\nour framework is straightforward.", "category": "hep-ph" }, { "text": "Neutrino Oscillations in Finite Time Path Out-of-Equilibrium Thermal\n Field Theory: We demonstrate that the Finite-Time-Path Field Theory is an adequate tool for\ncalculating neutrino oscillations. We apply this theory using a mass-mixing\nLagrangian which involves the correct Dirac spin and chirality structure and a\nPontecorvo-Maki-Nakagawa-Sakata (PMNS)-like mixing matrix. The model is exactly\nsolvable. The Dyson-Schwinger equations transform propagators of the input free\n(massless) flavor neutrinos into a linear combination of oscillating (massive)\nneutrinos. The results are consistent with the predictions of the PMNS matrix\nwhile allowing for extrapolation to early times.", "category": "hep-ph" }, { "text": "The Rare Top Decays $t \\to b W^+ Z$ and $t \\to c W^+ W^-$: The large value of the top quark mass implies that the rare top decays $t\n\\rightarrow b W^+ Z, s W^+ Z$ and $d W^+ Z$, and $t \\rightarrow c W^+ W^-$ and\n$u W^+ W^-$, are kinematically allowed decays so long as $m_t \\ge m_W + m_Z +\nm_{d_i} \\approx 171.5 GeV + m_{d_i}$ or $m_t \\ge 2m_W + m_{u,c} \\approx 160.6\nGeV + m_{u,c}$, respectively. The partial decay widths for these decay modes\nare calculated in the standard model. The partial widths depend sensitively on\nthe precise value of the top quark mass. The branching ratio for $t\\rightarrow\nb W^+ Z$ is as much as $2 \\times 10^{-5}$ for $m_t = 200 GeV$, and could be\nobservable at LHC. The rare decay modes $t \\rightarrow c W^+ W^-$ and $u W^+\nW^-$ are highly GIM-suppressed, and thus provide a means for testing the GIM\nmechanism for three generations of quarks in the u, c, t sector.", "category": "hep-ph" }, { "text": "Gluon-Meson Duality in the Mean Field Approximation: In a gauge-fixed language gluon-meson duality can be described as the Higgs\nmechanism for ``spontaneous symmetry breaking'' of color. We present a mean\nfield computation which suggests that this phenomenon is plausible in QCD. One\nobtains realistic masses of the light mesons and baryons.", "category": "hep-ph" }, { "text": "Facets of chiral perturbation theory: Chiral perturbation theory is the effective field theory of the Standard\nModel at low energies. After a short introduction and overview, I discuss three\ntopics where the chiral approach leads to a deeper understanding of low-energy\nhadron physics: radiative kaon decays, carbogenesis in stellar nucleosynthesis\nand the interplay of chiral perturbation theory and lattice QCD.", "category": "hep-ph" }, { "text": "Hidden Mass Hierarchy in QCD: We discuss implications of the recent measurements of the non-Abelian action\ndensity associated with the monopoles condensed in the confining phase of\ngluodynamics. The radius of the monopole determined in terms of the action was\nfound to be small numerically. As far as the condensation of the monopoles is\ndescribed in terms of a scalar field, a fine tuning is then implied. In other\nwords, a hierarchy exists between the self energy of the monopole and the\ntemperature of the confinement-deconfinement phase transition. The ratio of the\ntwo scales is no less than a factor of 10. Moreover, we argue that the\nhierarchy scale can well eventually extend to a few hundred GeV on the\nultraviolet side. The corresponding phenomenology is discussed, mostly within\nthe polymer picture of the monopole condensation.", "category": "hep-ph" }, { "text": "Asymmetry of Strange Sea in Nucleons: Based on the finite-temperature field theory, we evaluate the medium effects\nin nucleon which can induce an asymmetry between quarks and antiquarks of the\nstrange sea. The short-distance effects determined by the weak interaction can\ngive rise to $\\delta m\\equiv \\Delta m_s-\\Delta m_{\\bar s}$ where $\\Delta\nm_{s(\\bar s)}$ is the medium-induced mass of strange quark by a few KeV at\nmost, but the long-distance effects by strong interaction are sizable. Our\nnumerical results show that there exists an obvious mass difference between\nstrange and anti-strange quarks, as large as 10-100 MeV.", "category": "hep-ph" }, { "text": "Pileup and Underlying Event Mitigation with Iterative Constituent\n Subtraction: The hard-scatter processes in hadronic collisions are often largely\ncontaminated with soft background coming from pileup in proton-proton\ncollisions, or underlying event in heavy-ion collisions. This paper presents a\nnew background subtraction method for jets and event observables (such as\nmissing transverse energy) which is based on the previously published\nConstituent Subtraction algorithm. The new subtraction method, called Iterative\nConstituent Subtraction, applies event-wide implementation of Constituent\nSubtraction iteratively in order to fully equilibrate the background\nsubtraction across the entire event. Besides documenting the new method, we\nprovide guidelines for setting the free parameters of the subtraction\nalgorithm. Using particle-level simulation, we provide a comparison of\nIterative Constituent Subtraction with several existing methods from which we\nconclude that the new method has a significant potential to improve the\nbackground mitigation in both proton-proton and heavy-ion collisions.", "category": "hep-ph" }, { "text": "Divergences in anomalous dimension matrices of quarks at three loops:\n Explanation and simple solution: Three-loop counterterms for the Standard Model (SM) revealed that the matrix\nof anomalous dimensions ($\\gamma$) of quarks is divergent in the $d \\to 4$\nlimit unless a carefully chosen non-Hermitian square-root of $Z$ matrix is used\nin the textbook formula for $\\gamma$. Here, an alternative prescription is\ngiven, which expresses $\\gamma$ and $\\beta$ functions directly in terms of\ncounterterms (instead of $\\sqrt{Z}$ and conventional `bare couplings') and\nproduces finite results. In the SM, this prescription $automatically$\nreproduces results obtained previously by adjusting $\\sqrt{Z}$.", "category": "hep-ph" }, { "text": "Peak shifts due to $B^{(*)}-\\bar{B}^{(*)}$ rescattering in\n $\u03a5(5S)$ dipion transitions: We study the energy distributions of dipion transitions $\\Upsilon(5S)$ to\n$\\Upsilon(1S,2S,3S)\\pi^+\\pi^-$ in the final state rescattering model. Since the\n$\\Upsilon(5S)$ is well above the open bottom thresholds, the dipion transitions\nare expected to mainly proceed through the real processes $\\Upsilon(5S)\\to\nB^{(*)}\\bar{B}^{(*)}$ and $B^{(*)}\\bar{B}^{(*)}\\to\n\\Upsilon(1S,2S,3S)\\pi^+\\pi^-$. We find that the energy distributions of\n$\\Upsilon(1S,2S,3S)\\pi^+\\pi^-$ markedly differ from that of $\\Upsilon(5S)\\to\nB^{(*)}\\bar{B}^{(*)}$. In particular, the resonance peak will be pushed up by\nabout 7-20 MeV for these dipion transitions relative to the main hadronic decay\nmodes. These predictions can be used to test the final state rescattering\nmechanism in hadronic transitions for heavy quarkonia above the open flavor\nthresholds.", "category": "hep-ph" }, { "text": "Quark Model, Nonperturbative Wave Functions, the QCD Sum Rules and\n Instantons: The main subject of these lectures is the Nonperturbative Wave Functions. We\ndescribe some nonperturbative methods (like QCD sum rules, dispersion\nrelations, duality etc) in order to study this object. We also consider some\napplications of the obtained results, such as form factors, inclusive\namplitudes and diffractive electroproduction. Finally, we discuss the instanton\nliquid model which may help us to understand the success of the constituent\nquark model.", "category": "hep-ph" }, { "text": "WIMP Dark Matter in a Well-Tempered Regime: A case study on\n Singlet-Doublets Fermionic WIMP: Serious searches for the weakly interacting massive particle (WIMP) have now\nbegun. In this context, the most important questions that need to be addressed\nare: \"To what extent can we constrain the WIMP models in the future?\" and \"What\nwill then be the remaining unexplored regions in the WIMP parameter space for\neach of these models?\" In our quest to answer these questions, we classify WIMP\nin terms of quantum number and study each case adopting minimality as a guiding\nprinciple. As a first step, we study one of the simple cases of the minimal\ncomposition in the well-tempered fermionic WIMP regime, namely the\nsinglet-doublets WIMP model. We consider all available constraints from direct\nand indirect searches and also the predicted constraints coming from the near\nfuture and the future experiments. We thus obtain the current status, the near\nfuture prospects and the future prospects of this model in all its generality.\nWe find that in the future, this model will be constrained almost solely by the\nfuture direct dark matter detection experiments (as compared to the weaker\nindirect and collider constraints) and the cosmological (relic density)\nconstraints and will hence be gradually pushed to the corner of the\ncoannihilation region, if no WIMP signal is detected. Future lepton colliders\nwill then be useful in exploring this region not constrained by any other\nexperiments.", "category": "hep-ph" }, { "text": "${\\mathcal O}(\u03b1_s)$ corrections to $e^+e^-\\rightarrow\n J/\u03c8+\u03b7_{c2}(\u03c7_{c1}^\\prime)$ at $B$ factories: We investigate the ${\\cal O}(\\alpha_s)$ correction to $e^+e^-\\to\nJ/\\psi+\\eta_{c2}$ in the NRQCD factorization approach. A detailed comparative\nstudy between $e^+e^-\\to J/\\psi+\\eta_{c2}$ and $e^+e^-\\to\nJ/\\psi+\\chi^\\prime_{c1}$ at $B$ factory energy is also carried out. After\nincorporating the ${\\cal O}(\\alpha_s)$ correction, we predict the cross section\nfor the former process to be around 0.3 fb, while that of the latter about 6\ntimes greater. The outgoing $J/\\psi$ is found to be dominantly\ntransversely-polarized in the former process, while longitudinally-polarized in\nthe latter. These features may provide valuable guidance for the future\nexperiment to examine the ${}^3P_1$ or ${}^1D_2$ charmonium option of the\nX(3872) meson through the exclusive double-charmonium production processes. The\nobservation potential of $e^+e^-\\to J/\\psi+\\chi^\\prime_{c1}$ looks bright for\nthe current data sample of the \\textsc{Belle} experiment, provided that the\n$\\chi^\\prime_{c1}$ is indeed the narrow X(3872) state. In the appendix, we also\nidentify the coefficients of the double logarithms of form $\\ln^2(s/m_c^2)$\nassociated with all the relevant next-to-leading order Feynman diagrams, for\nthe helicity-suppressed double-charmonium production channels $e^+ e^- \\to\nJ/\\psi+ \\eta_{c2}(\\eta_c,\\chi_{c0,1,2})$.", "category": "hep-ph" }, { "text": "Baryogenesis from L-violating Higgs-doublet decay in the density-matrix\n formalism: We compute in the density-matrix formalism the baryon asymmetry generated by\nthe decay of the Higgs doublet into a right-handed (RH) neutrino and a Standard\nModel lepton. The emphasis is put on the baryon asymmetry produced by the total\nlepton-number violating decay. From the derivation of the corresponding\nevolution equations, and from their integration, we find that this contribution\nis fully relevant for large parts of the parameter space. This confirms the\nresults found recently in the CP-violating decay formalism with thermal\ncorrections and shows in particular that the lepton-number violating processes\nare important not only for high-scale leptogenesis but also when the\nRH-neutrino masses are in the GeV range. For large values of the Yukawa\ncouplings, we also find that the strong washout is generically much milder for\nthis total lepton-number violating part than for the usual RH-neutrino\noscillation flavour part.", "category": "hep-ph" }, { "text": "Bs to mu mu gamma from Bs to mu mu: The Bs to mu mu gamma decay offers sensitivity to a wider set of effective\noperators than its non-radiative counterpart Bs to mu mu, and a set that is\ninteresting in the light of present-day discrepancies in flavour data. On the\nother hand, the direct measurement of the Bs to mu mu gamma decay poses\nchallenges with respect to the Bs to mu mu one. We present a novel strategy to\nsearch for Bs to mu mu gamma decays in the very event sample selected for Bs to\nmu mu searches. The method consists in extracting the Bs to mu mu gamma\nspectrum as a \"contamination\" to the Bs to mu mu one, as the signal window for\nthe latter is extended downward with respect to the peak region. We provide\narguments for the actual practicability of the method already on Run-2 data of\nthe LHC.", "category": "hep-ph" }, { "text": "Correlation femtoscopy of small systems: The basic principles of the correlation femtoscopy, including its\ncorrespondence to the Hanbury Brown and Twiss intensity interferometry, are\nre-examined. The main subject of the paper is an analysis of the correlation\nfemtoscopy when the source size is as small as the order of the uncertainty\nlimit. It is about 1 fm for the current high energy experiments. Then the\nstandard femtoscopy model of random sources is inapplicable. The uncertainty\nprinciple leads to the partial indistinguishability and coherence of closely\nlocated emitters that affect the observed femtoscopy scales. In thermal systems\nthe role of corresponding coherent length is taken by the thermal de Broglie\nwavelength that also defines the size of a single emitter. The formalism of\npartially coherent phases in the amplitudes of closely located individual\nemitters is used for the quantitative analysis. The general approach is\nillustrated analytically for the case of the Gaussian approximation for\nemitting sources. A reduction of the interferometry radii and a suppression of\nthe Bose-Einstein correlation functions for small sources due to the\nuncertainty principle are found. There is a positive correlation between the\nsource size and the intercept of the correlation function. The peculiarities of\nthe non-femtoscopic correlations caused by minijets and fluctuations of the\ninitial states of the systems formed in $pp$ and $e^+e^-$ collisions are also\nanalyzed. The factorization property for the contributions of femtoscopic and\nnon-femtoscopic correlations into complete correlation function is observed in\nnumerical calculations in a wide range of the model parameters.", "category": "hep-ph" }, { "text": "Dirac Neutrinos and Hybrid Inflation from String Theory: We consider a possible scenario for the generation of Dirac neutrino masses\nmotivated by Type I string theory. The smallness of the neutrino Yukawa\ncouplings is explained by an anisotropic compactification with one\ncompactification radius larger than the others. In addition to this we utilise\nsmall Yukawa couplings to develop strong links between the origin of neutrino\nmasses and the physics driving inflation. We construct a minimal model which\nsimultaneously accommodates small Dirac neutrino masses leading to bi-large\nlepton mixing as well as an inflationary solution to the strong CP and to the\n$\\mu$ problem.", "category": "hep-ph" }, { "text": "RGE, the naturalness problem and the understanding of the Higgs mass\n term: The naturalness problem might be studied on the complex two dimensional plane\nwith the technique of dimensional regularization(DREG). The Renormalization\ngroup equation(RGE) of the Higgs mass on the plane suggests the Higgs mass\napproaches zero at ultraviolate (UV) scale, the scale can be Planck scale when\nthe top quark pole mass $M_{t}=168$ GeV. The real issue of the naturalness\nproblem in the sense of Wilsonian renormalization group method is not about\nquadratic divergences but the rescaling effect. The Higgs mass can be\nconsidered to be one composed mass. All terms in the lagrangian in this\nscenario are marginal terms and no relevant terms are left, thus no rescaling\neffect to cause the naturalness problem anymore. RGE of the vacuum expectation\nvalue (VEV) in the Landau gauge up to two-loop order is studied.\nScale-dependent behavior of the composed Higgs mass shows that we can have one\ntiny Higgs mass at high energy scale, even around the Planck scale, when\n$M_{t}\\leq170.7$ GeV.", "category": "hep-ph" }, { "text": "Parton densities and structure functions at next-to-next-to-leading\n order and beyond: We summarize recent results on the evolution of unpolarized parton densities\nand deep-inelastic structure functions in massless perturbative QCD. Due to\nlast year's extension of the integer-moment calculations of the three-loop\nsplitting functions, the NNLO evolution of the parton distributions can now be\nperformed reliably at momentum fractions x >= 10^-4, facilitating a\nconsiderably improved theoretical accuracy of their extraction from data on\ndeep-inelastic scattering. The NNLO corrections are not dominated, at relevant\nvalues of x, by their leading small-x terms. At large x the splitting-function\nseries converges very rapidly, hence, employing results on the three-loop\ncoefficient functions, the structure functions can be analysed at N^3LO for x >\n10^-2. The resulting values for alpha_s do not significantly change beyond\nNNLO, their renormalization scale dependence reaches about +-1% at N^3LO.", "category": "hep-ph" }, { "text": "Unitarity and Fermion Mass Generatation: Some years ago Appelquist and Chanowitz considered the scattering of\nfermion--anti-fermion into a pair of longitudinal gauge bosons. Their\ncalculation established that unitarity implies that the physics giving mass to\na quark of mass $m_f$ must be below a mass scale of $16 \\pi v^2 / m_f$ ($v=246$\nGeV). This bound is a bit difficult to interpret, because the unitarity of\ngauge boson scattering requires in any case that there be new physics, such as\na Higgs boson, with a mass lighter than this. This paper re-examines the\nAppelquist-Chanowitz bound in order to clarify its meaning. This work uses toy\nmodels with a singlet Higgs boson to unitarize gauge boson scattering, and\nconsiders other possibilities for the new physics affecting the fermion mass.\nThis new physics has the effect of changing the Higgs\nboson--fermion--anti-fermion coupling. New physics cannot significantly alter\nthis coupling unless it is substantially lighter than the Appelquist-Chanowitz\nbound.", "category": "hep-ph" }, { "text": "Effect of finite volume on thermodynamics of quark-hadron matter: The effects of a finite system volume on thermodynamic quantities, such as\nthe pressure, energy density, specific heat, speed of sound, conserved charge\nsusceptibilities and correlations, in hot and dense strongly interacting matter\nare studied within the parity-doublet Chiral Mean Field (CMF) model.\n Such an investigation is motivated by relativistic heavy-ion collisions,\nwhich create a blob of hot QCD matter of a finite volume, consisting of\nstrongly interacting hadrons and potentially deconfined quarks and gluons.\n The effect of the finite volume of the system is incorporated by introducing\na lower momentum cut-offs in the momentum integrals appearing in the model, the\nnumerical value of the momentum cut-off being related to the de Broglie\nwavelength of the given particle species.\n It is found that some of these quantities show a significant volume\ndependence, in particular those sensitive to pion degrees of freedom, and the\ncrossover transition is generally observed to become smoother in finite volume.\n These findings are relevant for the effective equation of state used in fluid\ndynamical simulations of heavy-ion collisions and efforts to extract the freeze\nout properties of heavy-ion collisions with susceptibilities involving electric\ncharge and strangeness.", "category": "hep-ph" }, { "text": "Twisted particles in heavy-ion collisions: The importance of production of twisted (vortex) particles in heavy-ion\ncollisions is analyzed. Free twisted particles can possess giant intrinsic\norbital angular momenta. Twisted particles are spatially localized and can be\nrather ubiquitous in laboratories and nature. Twisted photons have nonzero\neffective masses. Charged twisted particles can be recognized by their\ndynamics, magnetic moments, and specific effects in external fields.", "category": "hep-ph" }, { "text": "Neutrino Masses and Absence of Flavor Changing Interactions in the 2HDM\n from Gauge Principles: We propose several Two Higgs Doublet Models with the addition of an Abelian\ngauge group which free the usual framework from flavor changing neutral\ninteractions and explain neutrino masses through the seesaw mechanism. We\ndiscuss the kinetic and mass-mixing gripping phenomenology which encompass\nseveral constraints coming from atomic parity violation, the muon anomalous\nmagnetic moment, rare meson decays, Higgs physics, LEP precision data,\nneutrino-electron scattering, low energy accelerators and LHC probes.", "category": "hep-ph" }, { "text": "Open-source QCD analysis of nuclear parton distribution functions at NLO\n and NNLO: We present new sets of nuclear parton distribution functions (nPDFs) at\nnext-to-leading order (NLO) and next-to-next-to-leading order (NNLO). Our\nanalyses are based on deeply inelastic scattering data with charged-lepton and\nneutrino beams on nuclear targets. In addition, a set of proton baseline PDFs\nis fitted within the same framework with the same theoretical assumptions. The\nresults of this global QCD analysis are compared to existing nPDF sets and to\nthe fitted cross sections. Also, the uncertainties resulting from the limited\nconstraining power of the included experimental data are presented. The\npublished work is based on an open-source tool, xFitter, which has been\nmodified to be applicable also for a nuclear PDF analysis. The required\nextensions of the code are discussed as well.", "category": "hep-ph" }, { "text": "The Elusiveness of Infrared Critical Exponents in Landau Gauge\n Yang--Mills Theories: We solve a truncated system of coupled Dyson-Schwinger equations for the\ngluon and ghost propagators in SU($N_c$) Yang-Mills theories in Faddeev-Popov\nquantization on a four-torus. This compact space-time manifold provides an\nefficient mean to solve the gluon and ghost Dyson-Schwinger equations without\nany angular approximations. We verify that analytically two power-like\nsolutions in the very far infrared seem possible. However, only one of these\nsolutions can be matched to a numerical solution for non-vanishing momenta. For\na bare ghost-gluon vertex this implies that the gluon propagator is only weakly\ninfrared vanishing, $D_{gl}(k^2) \\propto (k^2)^{2\\kappa -1}$, $\\kappa \\approx\n0.595$, and the ghost propagator is infrared singular, $D_{gh}(k^2) \\propto\n(k^2)^{-\\kappa -1}$. For non-vanishing momenta our solutions are in agreement\nwith the results of recent SU(2) Monte-Carlo lattice calculations. The running\ncoupling possesses an infrared fixed point. We obtain $\\alpha(0) = 8.92/N_c$\nfor all gauge groups SU($N_c$). Above one GeV the running coupling rapidly\napproaches its perturbative form.", "category": "hep-ph" }, { "text": "Self-consistent Gaussian model of nonperturbative QCD vacuum: We show that the minimal Gaussian model of nonlocal vacuum quark and\nquark-gluon condensates in QCD generates the non-transversity of vector current\ncorrelators. We suggest the improved Gaussian model of the nonperturbative QCD\nvacuum, which respects QCD equations of motion and minimizes the revealed\ngauge-invariance breakdown. We obtain the refined values of pion distribution\namplitude (DA) conformal moments using the improved QCD vacuum model and\nconstruct the allowed region for Gegenbauer coefficients a_2 and a_4 of the\npion DA.", "category": "hep-ph" }, { "text": "Implementing inverse seesaw mechanism in SU(3)xSU(4)xU(1) gauge models: Generating appropriate tiny neutrino masses via inverse seesaw mechanism\nwithin the framework of a particular SU(3)xSU(4)xU(1) gauge model is the main\noutcome of this letter. It is achieved by simply adding three singlet exotic\nMajorana neutrinos to the usual ones included in the three lepton quadruplet\nrepresentations. The theoretical device of treating gauge models with high\nsymmetries is the general method by Cotaescu. It provides us with a unique free\nparameter (a) to be tuned in order to get a realistic mass spectrum for the\ngauge bosons and charged fermions in the model. The overall breaking scale can\nbe set around 1-10 TeV so its phenomenology is quite testable at present\nfacilities.", "category": "hep-ph" }, { "text": "Can supercooling explain the HBT puzzle?: Possible hadronization of supercooled QGP, created in heavy ion collisions at\nRHIC and SPS, is discussed within a Bjorken hydrodynamic model. Such a\nhadronization is expected to be a very fast shock-like process, what, if\nhadronization coincides or shortly followed by freeze out, could explain a part\nof the HBT puzzle, i.e. the flash-like particle emission\n($R_{out}/R_{side}\\approx 1$). HBT data also show that the expansion time\nbefore freeze out is very short ($\\sim 6-10 fm/c$). In this work we discuss\nquestion of supercooled QGP and the timescale of the reaction.", "category": "hep-ph" }, { "text": "R-parity violating anomaly mediated supersymmetry breaking: We propose a new scenario that solves the slepton negative mass squared\nproblem of the minimal supersymmetric standard model with anomaly mediated\nsupersymmetry breaking. The solution is achieved by including three trilinear\nR-parity violating operators in the superpotential. The soft supersymmetry\nbreaking terms satisfy renormalisation group invariant relations in terms of\nsupersymmetric couplings and the overall supersymmetry breaking mass scale.\nFlavour changing neutral currents can be naturally highly suppressed. A\nspecific model predicts tan beta=4.2+/-1.0. Excluding sleptons, the\nsupersymmetric particle spectrum then depends upon two remaining free\nparameters. In the case of the R-parity violating couplings set at their\nquasi-fixed points at a supersymmetric GUT scale, the whole sparticle spectrum\napproximately depends upon only one free parameter. Imposing experimental\nlimits leads to a constrained and distinctive phenomenology. The lightest\nCP-even Higgs of mass m_h=118 GeV would be seen at the Tevatron. All sparticles\nand heavy Higgs would evade detection except for the lightest charginos and\nneutralinos, whose distinctive leptonic decays would be seen at the LHC.", "category": "hep-ph" }, { "text": "On the Hadronic light-by-light contribution to the muon $g-2$: This talk is about the hadronic light-by-light contribution to the muon\nanomalous magnetic moment, mainly our old work but including some newer results\nas well. It concentrates on the model calculations. Most attention is paid to\npseudo-scalar exchange and the pion loop contribution. Scalar, $a_1$-exchange\nand other contributions are shortly discussed as well. For the $\\pi^0$-exchange\na possible large cancellation between connected and disconnected diagrams is\nexpected.", "category": "hep-ph" }, { "text": "$A_0$ condensation, Nielsen's identity and effective potential of order\n parameter: In high temperature SU(2) gluodynamics, the condensation of the zero\ncomponent gauge field potential A_0 =const and its gauge-fixing dependence are\ninvestigated. A_0 is mutually related with Polyakov's loop . The two-loop\neffective potential W(A_0,xi) is recalculated in the background relativistic\nR_xi gauge. It depends on the parameter xi, has a nontrivial minimum and\nsatisfies Nielsen's identity. These signs mean gauge invariance of the\ncondensation phenomenon.\n Following the idea of Belyaev, we express W(A_0,xi) in terms of . The\nobtained effective potential of order parameter differs from that derived by\nthis author. It is independent of xi and has a nontrivial minimum position.\nHence the A_0 condensation follows. We show that the equation relating A_0 and\n(A_0)|_(classical) coincides with the special characteristic orbit in the\n(A)$-plain along which the W(A_0,xi) is xi-independent. In this way the link\nbetween these two gauge invariant descriptions is established. The minimum\nvalue of the Polyakov loop is calculated. Comparison with results of other\nauthors is given.", "category": "hep-ph" }, { "text": "Some results from the NA27 Data: The self-affine analysis and erraticity analysis of pseudorapidity gaps are\nperformed for the data of 400GeV/$c$ pp collisions. The self-affine analysis\nhas been shown to exhibit a better scaling behavior. The self-affine\nmultifractal dimensions and multifractal spectrum have been obtained. The\nsimulated results using FRITIOF program can not reproduce the scaling behavior.\nThe analysis of event-to-event fluctuations has been performed. The increase of\nevent-space moments $C_{p,q}(M)$ with decreasing phase-space scale is dominated\nby the statistical fluctuations. The erraticity analysis based on measuring the\npseudorapidity gaps is also performed. The entropy-like quantities $S_q$ and\n$\\Sigma_q$ deviate from 1 significantly, implying that both of them are useful\nto serve as effective measures of erraticity in multiparticle production. The\nln${S_q}$ versus $q$ has a quite linear behavior, but the ln${\\Sigma_q}$ versus\n$q$ has only an approximate linear behavior. The FRITIOF simulated results\nfollow the same scaling behavior, but the deviations from the experimental data\nare rather large.", "category": "hep-ph" }, { "text": "Theory of heavy quark energy loss: We briefly review some of the models and theoretical schemes established to\ndescribe heavy quark quenching in ultrarelativistic heavy ions collisions. Some\nlessons are derived from RHIC and early LHC data, especially as for the\ncontraints they impose on those models.", "category": "hep-ph" }, { "text": "Anomalies in charged-current $B$ decays: This paper reviews the recent progresses of the flavor and collider searches\nthat can probe New Physics effects responsible for the current discrepancy in\nthe lepton flavor universality ratio of $R_{D^{(*)}}$ between the experimental\nmeasurements and SM values.", "category": "hep-ph" }, { "text": "Pseudoscalar Meson Decay Constants and Couplings, the Witten-Veneziano\n Formula beyond large N_c, and the Topological Susceptibility: The QCD formulae for the radiative decays $\\eta,\\eta'\\to\\c\\c$, and the\ncorresponding Dashen--Gell-Mann--Oakes--Renner relations, differ from\nconventional PCAC results due to the gluonic $U(1)_A$ axial anomaly. This\nintroduces a critical dependence on the gluon topological susceptibility. In\nthis paper, we revisit our earlier theoretical analysis of radiative\npseudoscalar decays and the DGMOR relations and extract explicit experimental\nvalues for the decay constants. This is our main result. The flavour singlet\nDGMOR relation is the generalisation of the Witten-Veneziano formula beyond\nlarge $N_c$, so we are able to give a quantitative assessment of the\nrealisation of the $1/N_c$ expansion in the $U(1)_A$ sector of QCD.\nApplications to other aspects of $\\eta'$ physics, including the relation with\nthe first moment sum rule for the polarised photon structure function $g_1^\\c$,\nare highlighted. The $U(1)_A$ Goldberger-Treiman relation is extended to\naccommodate SU(3) flavour breaking and the implications of a more precise\nmeasurement of the $\\eta$ and $\\eta'$-nucleon couplings are discussed. A\ncomparison with the existing literature on pseudoscalar meson decay constants\nusing large-$N_c$ chiral Lagrangians is also made.", "category": "hep-ph" }, { "text": "The KLN Theorem and Soft Radiation in Gauge Theories: Abelian Case: We present a covariant formulation of the Kinoshita, Lee, Nauenberg (KLN)\ntheorem for processes involving the radiation of soft particles. The role of\nthe disconnected diagrams is explored and a rearrangement of the perturbation\ntheory is performed such that the purely disconnected diagrams are factored\nout. The remaining effect of the disconnected diagrams results in a simple\nmodification of the usual Feynman rules for the S-matrix elements. As an\napplication, we show that when combined with the Low theorem, this leads to a\nproof of the absense of the $1/Q$ corrections to inclusive processes (like the\nDrell-Yan process). In this paper the abelian case is discussed to all orders\nin the coupling.", "category": "hep-ph" }, { "text": "Baryon Number, Lepton Number, and Operator Dimension in the Standard\n Model: We prove that for a given operator in the Standard Model (SM) with baryon\nnumber B and lepton number L, that the operator's dimension is even (odd) if\n(B-L)/2 is even (odd). Consequently, this establishes the veracity of\nstatements that were long observed or expected to be true, but not proven,\ne.g., operators with B-L=0 are of even dimension, B-L must be an even number,\netc. These results remain true even if the SM is augmented by any number of\nright-handed neutrinos with L=1.", "category": "hep-ph" }, { "text": "High-Energy Proton-Proton Forward Scattering and Derivative Analyticity\n Relations: We present the results of several parametrizations to two different ensemble\nof data on $pp$ total cross sections $\\sigma_{tot}^{pp}$ at the highest\ncenter-of-mass energies (including cosmic-ray information). The results are\nstatistically consistent with two distinct scenarios at high energies. From one\nensemble the prediction for the LHC ($\\sqrt s = 14$ TeV) is $\\sigma_{tot}^{pp}\n= 113 \\pm 5$ mb and from the other, $\\sigma_{tot}^{pp}=140 \\pm 7$ mb. From each\nparametrization, and making use of derivative analyticity relations (DAR), we\ndetermine $\\rho(s)$ (ratio between the forward real and imaginary parts of the\nelastic scattering amplitude). A discussion on the optimization of the DAR in\nterms of a free parameter is also presented.In all cases good descriptions of\nthe experimental data are obtained.", "category": "hep-ph" }, { "text": "Light scalar mesons and charmless hadronic $B_c \\to SP, SV$ decays in\n the perturbative QCD approach: In this work, based on the assumption of two-quark structure of the scalars,\nthe charmless hadronic $B_c \\to SP, SV$ decays(here, $S$, $P$, and $V$ denote\nthe light scalar, pseudoscalar, and vector mesons, respectively) are\ninvestigated by employing the perturbative QCD(pQCD) factorization\napproach.From our numerical evaluations and phenomenological analysis, we find\nthat (a) the pQCD predictions for the {\\it CP}-averaged branching ratios(BRs)\nof the considered $B_c$ decays vary in the range of $10^{-5}$ to $10^{-8}$,\nwhich will be tested in the ongoing LHCb and forthcoming Super-B experiments,\nwhile the {\\it CP}-violating asymmetries for these modes are absent naturally\nin the standard model because only one type tree operator is involved; %% (b)\nanalogous to $B \\to K^* \\eta^{(\\prime)}$ decays, $Br(B_c \\to \\kappa^+ \\eta)\n\\sim 5 \\times Br(B_c \\to \\kappa^+ \\eta^\\prime)$ in the pQCD approach, which can\nbe understood by the constructive and destructive interference between the\n$\\eta_q$ and $\\eta_s$ contributions to the $B_c \\to \\kappa^+ \\eta$ and $B_c \\to\n\\kappa^+ \\eta^\\prime$ decays, however, $Br(B_c \\to K_0^*(1430) \\eta)$ is\napproximately equal to $Br(B_c \\to K_0^*(1430) \\eta')$ in both scenarios\nbecause the factorizable contributions from $\\eta_s$ term play the dominant\nrole in the considered two channels; %% (c) if $a_0(980)$ and $\\kappa$ are the\n$q\\bar q$ bound states, the pQCD predicted BRs for $B_c \\to a_0(980) (\\pi,\n\\rho)$ and $B_c \\to \\kappa K^{(*)}$ decays will be in the range of $10^{-6}\n\\sim 10^{-5}$, which are within the reach of the LHCb experiments and could be\nmeasured in the near future; and %% (d) for the $a_0(1450)$ and $K_0^*(1430)$\nchannels, the BRs for $B_c \\to a_0(1450) (\\pi, \\rho)$ and $B_c \\to K_0^*(1430)\nK^{(*)}$ modes in the pQCD approach are found to be $(5 \\sim 47) \\times\n10^{-6}$ and $(0.7 \\sim 36) \\times 10^{-6}$, respectively.", "category": "hep-ph" }, { "text": "The Mueller-Tang jet impact factor at NLO from the high energy effective\n action: We report on recent progress in the evaluation of next-to-leading order\nobservables using Lipatov's QCD high energy effective action. In this\ncontribution we focus on the determination of the real part of the\nnext-to-leading order corrections to the Mueller-Tang impact factor which is\nthe only missing element for a complete NLO BFKL description of quark induced\ndijet events with a rapidity gap.", "category": "hep-ph" }, { "text": "Spectroscopy of Exotic Hadrons Formed from Dynamical Diquarks: The dynamical diquark picture asserts that exotic hadrons can be formed from\nwidely separated colored diquark or triquark components. We use the\nBorn-Oppenheimer (BO) approximation to study the spectrum of states thus\nconstructed, both in the basis of diquark spins and in the basis of heavy\nquark-antiquark spins. We develop a compact notation for naming these states,\nand use the results of lattice simulations for hybrid mesons to predict the\nlowest expected BO potentials for both tetraquarks and pentaquarks. We then\ncompare to the set of exotic candidates with experimentally determined quantum\nnumbers, and find that all of them can be accommodated. Once decay modes are\nalso considered, one can develop selection rules of both exact ($J^{PC}$\nconservation) and approximate (within the context of the BO approximation)\ntypes and test their effectiveness. We find that the most appealing way to\nsatisfy both sets of selection rules requires including additional low-lying BO\npotentials, a hypothesis that can be checked on the lattice.", "category": "hep-ph" }, { "text": "Higgs Inflation, Reheating and Gravitino Production in No-Scale\n Supersymmetric GUTs: We extend our previous study of supersymmetric Higgs inflation in the context\nof no-scale supergravity and grand unification, to include models based on the\nflipped SU(5) and the Pati-Salam group. Like the previous SU(5) GUT model,\nthese yield a class of inflation models whose inflation predictions interpolate\nbetween those of the quadratic chaotic inflation and Starobinsky-like\ninflation, while avoiding tension with proton decay limits. We further analyse\nthe reheating process in these models, and derive the number of e-folds, which\nis independent of the reheating temperature. We derive the corresponding\npredictions for the scalar tilt and the tensor-to-scalar ratio in cosmic\nmicrowave background perturbations, as well as discussing the gravitino\nproduction following inflation.", "category": "hep-ph" }, { "text": "Impact of Electroweak Corrections on Neutral Higgs Boson Decays in\n Extended Higgs Sectors: Precision predictions play an important role in the search for indirect New\nPhysics effects in the Higgs sector itself. For the electroweak (EW)\ncorrections of the Higgs bosons in extended Higgs sectors several\nrenormalization schemes have been worked out that provide\ngauge-parameter-independent relations between the input parameters and the\ncomputed observables. Our recently published program codes 2HDECAY and\newN2HDECAY allow for the computation of the EW corrections to the Higgs decay\nwidths and branching ratios of the Two-Higgs-Doublet Model (2HDM) and the\nNext-to-Minimal-2HDM (N2HDM) for different renormalization schemes of the\nscalar mixing angles. In this paper, we present a comprehensive and complete\noverview over the relative size of the EW corrections to the branching ratios\nof the 2HDM and N2HDM neutral Higgs bosons for different applied\nrenormalization schemes. We quantify the size of the EW corrections of Standard\nModel(SM)- and non-SM-like Higgs bosons and moreover also identify\nrenormalization schemes that are well-behaved and do not induce unnaturally\nlarge corrections. We furthermore pin down decays and parameter regions that\nfeature large EW corrections and need further treatment in order to improve the\npredictions. Our study sets the scene for future work in the computation of\nhigher-order corrections to the decays of non-minimal Higgs sectors.", "category": "hep-ph" }, { "text": "Lepton flavor-violating transitions in effective field theory and\n gluonic operators: Lepton flavor-violating processes offer interesting possibilities to probe\nnew physics at multi-TeV scale. We discuss those in the framework of effective\nfield theory, emphasizing the role of gluonic operators. Those operators are\nobtained by integrating out heavy quarks that are kinematically inaccessible at\nthe scale where low-energy experiments take place and make those experiments\nsensitive to the couplings of lepton flavor changing neutral currents to heavy\nquarks. We discuss constraints on the Wilson coefficients of those operators\nfrom the muon conversion $\\mu^- + (A,Z) \\to e^- + (A,Z)$ and from lepton\nflavor-violating tau decays with one or two hadrons in the final state, e.g.\n$\\tau \\to \\ell \\ \\eta^{(\\prime)}$ and $\\tau \\to \\ell \\ \\pi^+\\pi^-$ with $\\ell =\n\\mu, e$. To illustrate the results we discuss explicit examples of constraining\nparameters of leptoquark models.", "category": "hep-ph" }, { "text": "Open charm effects in the explanation of the long-standing \"$\u03c1\u03c0$\n puzzle\": A detailed analysis of the open charm effects on the decays of\n$J/\\psi(\\psi^\\prime)\\to VP$ is presented, where $V$ stands for light vector\nmeson and $P$ for light pseudoscalar meson. These are the channels that the\nso-called \"12% rule\" of perturbative QCD (pQCD) is obviously violated.\nNevertheless, they are also the channels that violate the pQCD helicity\nselection rule (HSR) at leading order. In this work, we put constraints on the\nelectromagnetic (EM) contribution, short-distance contribution from the\n$c\\bar{c}$ annihilation at the wavefunction origin, and long-distance\ncontribution from the open charm threshold effects on these two decays. We show\nthat interferences among these amplitudes, in particular, the destructive\ninterferences between the short-distance and long-distance strong amplitudes\nplay a key role to evade the HSR and cause the significant deviations from the\npQCD expected \"12% rule\".", "category": "hep-ph" }, { "text": "A fresh look at the generalized parton distributions of light\n pseudoscalar mesons: We present a symmetry-preserving scheme to derive the pion and kaon\ngeneralized parton distributions (GPDs) in Euclidean space. The key to\nmaintaining crucial symmetries under this approach is the treatment of the\nscattering amplitude, such that it contains both the traditional leading-order\ncontributions and the scalar/vector pole contribution automatically, the latter\nbeing necessary to ensure the soft-pion theorem. The GPD is extracted\nanalytically via the uniqueness and definition of the Mellin moments and we\nfind that it naturally matches the double distribution; consequently, the\npolynomiality condition and sum rules are satisfied. The present scheme thus\npaves the way for the extraction of the GPD in Euclidean space using the\nDyson-Schwinger equation framework or similar continuum approaches.", "category": "hep-ph" }, { "text": "Precision tools and models to narrow in on the 750 GeV diphoton\n resonance: The hints for a new resonance at 750 GeV from ATLAS and CMS have triggered a\nsignificant amount of attention. Since the simplest extensions of the standard\nmodel cannot accommodate the observation, many alternatives have been\nconsidered to explain the excess. Here we focus on several proposed\nrenormalisable weakly-coupled models and revisit results given in the\nliterature. We point out that physically important subtleties are often missed\nor neglected. To facilitate the study of the excess we have created a\ncollection of 40 model files, selected from recent literature, for the\nMathematica package SARAH. With SARAH one can generate files to perform\nnumerical studies using the tailor-made spectrum generators FlexibleSUSY and\nSPheno. These have been extended to automatically include crucial higher order\ncorrections to the diphoton and digluon decay rates for both CP-even and CP-odd\nscalars. Additionally, we have extended the UFO and CalcHep interfaces of\nSARAH, to pass the precise information about the effective vertices from the\nspectrum generator to a Monte-Carlo tool. Finally, as an example to demonstrate\nthe power of the entire setup, we present a new supersymmetric model that\naccommodates the diphoton excess, explicitly demonstrating how a large width\ncan be obtained. We explicitly show several steps in detail to elucidate the\nuse of these public tools in the precision study of this model.", "category": "hep-ph" }, { "text": "Tau Portal Dark Matter models at the LHC: Motivated by the Galactic Center gamma-ray excess in the Fermi-LAT data, we\nstudy the signatures of a class of tau portal dark matter (DM) models where DM\nparticles preferentially couple to tau leptons at the LHC. We consider the\nconstraints from the DM direct detection and investigate the sensitivity of the\nLHC to di-tau plus missing energy signatures. We find that the LHC with a high\nluminosity of 3000 fb$^{-1}$ can test the tau portal DM models with fermionic\nmediators in the mass range of $120\\sim450$ GeV.", "category": "hep-ph" }, { "text": "NLO QCD Corrections to $B_c$-to-Charmonium Form Factors: The $B_c(^1S_0)$ meson to S-wave Charmonia transition form factors are\ncalculated in next-to-leading order(NLO) accuracy of Quantum\nChromodynamics(QCD). Our results indicate that the higher order corrections to\nthese form factors are remarkable, and hence are important to the\nphenomenological study of the corresponding processes. For the convenience of\ncomparison and use, the relevant expressions in asymptotic form at the limit of\n$m_c\\rightarrow0$ for the radiative corrections are presented.", "category": "hep-ph" }, { "text": "Nucleon sea and the five-quark components: We generalize the approach of Brodsky {\\it et al.} for the intrinsic charm\nquark distribution in the nucleons to the light-quark sector involving\nintrinsic $\\bar u, \\bar d, s$ and $\\bar s$ sea quarks. We compare the\ncalculations with the existing $\\bar d - \\bar u$, $s + \\bar s$, and $\\bar u +\n\\bar d - s -\\bar s$ data. The good agreement between the theory and the data is\ninterpreted as evidence for the existence of the intrinsic light-quark sea in\nthe nucleons. The probabilities for the $|uudu\\bar{u}>$, $|uudd\\bar{d}>$ and\n$|uuds\\bar{s}>$ Fock states are also extracted.", "category": "hep-ph" }, { "text": "Optimizing the pulse shape for Schwinger pair production: Recent studies of the dynamically assisted Schwinger effect have shown that\nparticle production is significantly enhanced by a proper choice of the\nelectric field. We demonstrate that optimal control theory provides a\nsystematic means of modifying the pulse shape in order to maximize the particle\nyield. We employ the quantum kinetic framework and derive the relevant optimal\ncontrol equations. By means of simple examples we discuss several important\nissues of the optimization procedure such as constraints, initial conditions or\nscaling. By relating our findings to established results we demonstrate that\nthe particle yield is systematically maximized by this procedure.", "category": "hep-ph" }, { "text": "A Symmetry Approach to CP Violation: One of the greatest challenges for particle physics in the 1990's is\nunderstanding the broken symmetry of CP violation. It is now almost 30 years\nsince the discovery in 1964 of the $K_{L} \\rightarrow 2\\pi$ decay. What has\nhappened since? Why has there been no significant new experimental input in\nthis long period? The original $K_{L} \\rightarrow 2\\pi$ decay experiment is\ndescribed by two parameters $\\epsilon$ and $\\epsilon'$. Today $\\epsilon \\approx\n$ its 1964 value while $\\epsilon'$ still consistent with zero, and there is no\nnew evidence for CP violation outside the kaon system. Why is it so hard to\nfind CP violation? How can B Physics Help? We present a symmetry approach to\nthese questions.", "category": "hep-ph" }, { "text": "The anomalous dimension of spin-1/2 baryons in many flavors QCD: The anomalous dimension of spin-1/2 baryon operators in QCD is derived at\nleading 1/Nf order using the minimal subtraction scheme. A residual ambiguity,\noriginating from the presence of evanescent operators in dimensional\nregularization, is parametrized by a function of the renormalized coupling. Our\nresult is shown to agree with previous 2 and 3 loop calculations performed in\ntwo different renormalization schemes.", "category": "hep-ph" }, { "text": "On Equations for the Multi-quark Bound States in Nambu--Jona-Lasinio\n Model: In present report we review some preliminary results of investigation of\nhigher orders of mean-field expansion for Nambu--Jona-Lasinio model. We discuss\nfirst results of investigation of next-to-next-to-leading order of mean-field\nexpansion equations for four-quark and three-quark Green functions. We have\nconsidered equations for Green functions of Nambu--Jona-Lasinio model in\nmean-field expansion up to third order.", "category": "hep-ph" }, { "text": "The Reach of LHC (CMS) for Models with Effective Supersymmetry and\n Nonuniversal Gaugino Masses: We investigate squark and gluino pair production at LHC (CMS) with subsequent\ndecays into quarks, leptons and LSP in models with effective supersymmetry\nwhere third generation of squarks is relatively light while the first two\ngenerations of squarks are heavy. We consider the general case of nonuniversal\ngaugino masses. Visibility of signal by an excess over SM background in $(n\n\\geq 2)jets + (m \\geq 0)leptons + E^{miss}_T$ events depends rather strongly on\nthe relation between LSP, second neutralino, gluino and squark masses and it\ndecreases with the increase of LSP mass.", "category": "hep-ph" }, { "text": "Phase-shift analysis of low-energy $\u03c0^{\\pm}p$ elastic-scattering data: Using electromagnetic corrections previously calculated by means of a\npotential model, we have made a phase-shift analysis of the $\\pi^\\pm p$\nelastic-scattering data up to a pion laboratory kinetic energy of 100 MeV. The\nhadronic interaction was assumed to be isospin invariant. We found that it was\npossible to obtain self-consistent databases by removing very few measurements.\nA pion-nucleon model was fitted to the elastic-scattering database obtained\nafter the removal of the outliers. The model-parameter values showed an\nimpressive stability when the database was subjected to different criteria for\nthe rejection of experiments. Our result for the pseudovector $\\pi N N$\ncoupling constant (in the standard form) is $0.0733 \\pm 0.0014$. The six\nhadronic phase shifts up to 100 MeV are given in tabulated form. We also give\nthe values of the s-wave scattering lengths and the p-wave scattering volumes.\nBig differences in the s-wave part of the interaction were observed when\ncomparing our hadronic phase shifts with those of the current GWU solution. We\ndemonstrate that the hadronic phase shifts obtained from the analysis of the\nelastic-scattering data cannot reproduce the measurements of the $\\pi^- p$\ncharge-exchange reaction, thus corroborating past evidence that the hadronic\ninteraction violates isospin invariance. Assuming the validity of the result\nobtained within the framework of chiral perturbation theory, that the mass\ndifference between the $u$- and the $d$-quark has only a very small effect on\nthe isospin invariance of the purely hadronic interaction, the\nisospin-invariance violation revealed by the data must arise from the fact that\nwe are dealing with a hadronic interaction which still contains residual\neffects of electromagnetic origin.", "category": "hep-ph" }, { "text": "Double Lepton Polarization Forward--Backward Asymmetries in B \\rar\n K^\\ast \\ell^+ \\ell^- Decay in the SM4: This study examines the influence of the fourth generation quarks on the\ndouble lepton polarizations forward--backward asymmetries in B \\rar K^\\ast\n\\ell^+ \\ell^- decay. We obtain that for both (muon, tau) channels the magnitude\nand the sign of the differential forward--backward asymmetries and the\nmagnitude of the average forward--backward asymmetries are quite sensitive to\nthe 4th generation quarks mass and mixing parameters. It can serve as a good\ntool to search for new physics effects, precisely, to search for the fourth\ngeneration quarks(t', b') via its indirect manifestations in the loop diagrams.", "category": "hep-ph" }, { "text": "Gauge Extensions of Supersymmetric Models and Hidden Valleys: Supersymmetric models with extended group structure beyond the standard model\nare revisited in the framework of general gauge mediation. Sum rules for\nsfermion masses are shown to depend genuinely on the group structure, which can\nserve as important probes for specific models. The left-right model and models\nwith extra U(1) are worked out for illustrations. If the couplings of extra\ngauge groups are small, supersymmetric hidden valleys of the scale 10-100 GeV\ncan be naturally constructed in companion of a TeV-scale supersymmetric visible\nsector.", "category": "hep-ph" }, { "text": "Fermion Mixings in SU(9) Family Unification: In an SU(9) model of gauged family unification, we propose an explanation for\nwhy angles observed in the lepton flavor ({\\it PMNS}) mixing matrix are\nsignificantly larger than those measured for any analagous quark flavor ({\\it\nKM}) mixing angle. It is directly related to a see-saw mechanism that we assume\nto be responsible for the generation of neutrino masses. Our model is more\nconstrained and therefore even more predictive than a model previously proposed\nby Barr.", "category": "hep-ph" }, { "text": "Tadpole contribution to magnetic photon-graviton conversion: Photon-graviton conversion in a magnetic field is a process that is usually\nstudied at tree level, but the one-loop corrections due to scalars and spinors\nhave also been calculated. Differently from the tree-level process, at one-loop\none finds the amplitude to depend on the photon polarization, leading to\ndichroism. However, previous calculations overlooked a tadpole contribution of\nthe type that was considered to be vanishing in QED for decades but erroneously\nso, as shown by H. Gies and one of the authors in 2016. Here we compute this\nmissing diagram in closed form, and show that it does not contribute to\ndichroism.", "category": "hep-ph" }, { "text": "Accumulating Evidence for the Associated Production of a New Higgs Boson\n at the Large Hadron Collider: In the last decades, the Standard Model (SM) of particle physics has been\nextensively tested and confirmed, with the announced discovery of the Higgs\nboson in 2012 being the last missing puzzle piece. Even though since then the\nsearch for new particles and interactions has been further intensified, the\nexperiments ATLAS and CMS at the Large Hadron Collider (LHC) at CERN did not\nfind evidence for the direct production of a new state. However, in recent\nyears deviations between LHC data and SM predictions in multiple observables\ninvolving two or more leptons (electrons or muons) have emerged, the so-called\n``multi-lepton anomalies'', pointing towards the existence of a beyond the SM\nHiggs boson $S$. While from these measurements its mass cannot be exactly\ndetermined, it is estimated to lay in the range between $130\\,$GeV and\n$160\\,$GeV. Motivated by this observation, we perform a search for signatures\nof $S$, by using existing CMS and ATLAS analyses. Combining channels involving\nthe associate productions of SM gauge bosons ($\\gamma\\gamma$ and $Z\\gamma$), we\nfind that a simplified model with a new scalar with $m_S= 151.5\\,$GeV is\npreferred over the SM hypothesis by 4.3$\\sigma$ (3.9$\\sigma$) locally\n(globally). On the face of it, this provides a good indication for the\nexistence of a new scalar resonance $S$ decaying into photons, in association\nwith missing energy and allows for a connection to the long-standing problem of\nDark Matter. Furthermore, because $S$ is always produced together with other\nparticles, we postulate the existence of a second new (heavier) Higgs boson $H$\nthat decays into $S$ and propose novel searches to discover this particle,\nwhich can be performed by ATLAS and CMS.", "category": "hep-ph" }, { "text": "Flavour Physics in an SO(10) Grand Unified Model: Grand unified theories open the possibility to transfer the neutrino mixing\nmatrix U_PMNS to the quark sector. This is accomplished in a controlled way in\na supersymmetric grand-unified model proposed by Chang, Masiero and Murayama\n(CMM model) where the atmospheric neutrino mixing angle induces large new b ->\ns and tau -> mu transitions. Relating the supersymmetric low-energy parameters\nto seven new parameters a_0, m_0^2, m_tilde{g}, D, xi, tan beta and arg(mu) of\nthis SO(10) model, we perform a correlated study of several flavour-changing\nneutral current (FCNC) processes. The CMM model can serve as an alternative\nbenchmark scenario to the popular constraint MSSM.", "category": "hep-ph" }, { "text": "Selected topics on tau physics: The B Factories have generated a large amount of new results on the tau\nlepton. The present status of some selected topics on tau physics is presented:\ncharged-current universality tests, bounds on lepton-flavour violation, the\ndetermination of alpha_s from the inclusive tau hadronic width, and the\nmeasurement of |V_{us}| through the Cabibbo-suppressed decays of the tau\nlepton.", "category": "hep-ph" }, { "text": "Scattering amplitudes for e^+e^- --> 3 jets at next-to-next-to-leading\n order QCD: We present the calculation of the fermionic contribution to the QCD two-loop\namplitude for e^+e^- --> q qbar g.", "category": "hep-ph" }, { "text": "Critical QCD in Nuclear Collisions: A detailed study of correlated scalars, produced in collisions of nuclei and\nassociated with the $\\sigma$-field fluctuations, $(\\delta \\sigma)^2= < \\sigma^2\n>$, at the QCD critical point (critical fluctuations), is performed on the\nbasis of a critical event generator (Critical Monte-Carlo) developed in our\nprevious work. The aim of this analysis is to reveal suitable observables of\ncritical QCD in the multiparticle environment of simulated events and select\nappropriate signatures of the critical point, associated with new and strong\neffects in nuclear collisions.", "category": "hep-ph" }, { "text": "A lower bound on the Longitudinal Structure Function at small x from a\n self-similarity based model of Proton: Self-similarity based model of proton structure function at small \\textit{x}\nwas reported in the literature sometime back. The phenomenological validity of\nthe model is in the kinematical region $ 6.2\\, \\times \\, 10^{-7} \\leq x \\leq\n10^{-2}$ and $ 0.045 \\leq Q^{2} \\leq 120 \\, \\mathrm{GeV^{2}} $. We use momentum\nsum rule to pin down the corresponding self-similarity based gluon distribution\nfunction valid in the same kinematical region. The model is then used to\ncompute bound on the longitudinal structure function $F_{L}\\left(x,Q^{2}\n\\right)$ for Altarelli-Martinelli equation in QCD and is compared with the\nrecent HERA data.", "category": "hep-ph" }, { "text": "Bounding Lorentz Violation at Particle Colliders By Tracking the Motion\n of Charged Particles: In the presence of Lorentz violation, the motion of a charged particle in a\nmagnetic field is distorted. By measuring the eccentricities of particles'\nelliptical orbits and studying how those eccentricities vary with the absolute\norientation of the laboratory, it is possible to constrain the\nLorentz-violating c_JK parameters. For each observed species, this method can\nprovide constraints on four linear combinations of coefficients for which, in\nsome species, there are presently no two-sided bounds.", "category": "hep-ph" }, { "text": "Application of High Quality Antiproton Beam with Momentum Ranging from 1\n GeV/c to 15 GeV/c to Study Charmonium and Charmed Hybrids: The elaborate analysis of spectrum of charmonium states and charmed hybrids\nin the mass region over DD-threshold is given. The combined approach based on\nthe potential model and relativistic spherical symmetric top model for decay\nproducts has been proposed. The experimental data from different collaborations\nwere analyzed. Especial attention was given to the new states with the hidden\ncharm discovered recently. Eight of these states may be interpreted as higher\nlaying radial excited charmoniumstates. Butmuchmore data on different decay\nmodes are needed for deeper analysis. These data can be derived directly from\nthe experiments using high quality antiproton beam with the momentum ranging\nfrom 1 GeV/c to 15 GeV/c (PANDA experiment at FAIR).", "category": "hep-ph" }, { "text": "Deep learning for the R-parity violating supersymmetry searches at the\n LHC: Supersymmetry with hadronic R-parity violation in which the lightest\nneutralino decays into three quarks is still weakly constrained. This work aims\nto further improve the current search for this scenario by the boosted decision\ntree method with additional information from jet substructure. In particular,\nwe find a deep neural network turns out to perform well in characterizing the\nneutralino jet substructure. We first construct a Convolutional Neutral Network\n(CNN) which is capable of tagging the neutralino jet in any signal process by\nusing the idea of jet image. When applied to pure jet samples, such a CNN\noutperforms the N-subjettiness variable by a factor of a few in tagging\nefficiency. Moreover, we find the method, which combines the CNN output and jet\ninvariant mass, can perform better and is applicable to a wider range of\nneutralino mass than the CNN alone. Finally, the ATLAS search for the signal of\ngluino pair production with subsequent decay $\\tilde{g} \\to q q\n\\tilde{\\chi}^0_1 (\\to q q q)$ is recasted as an application. In contrast to the\npure sample, the heavy contamination among jets in this complex final state\nrenders the discriminating powers of the CNN and N-subjettiness similar. By\nanalyzing the jets substructure in events which pass the ATLAS cuts with our\nCNN method, the exclusion limit on gluino mass can be pushed up by $\\sim200$\nGeV for neutralino mass $\\sim 100$ GeV.", "category": "hep-ph" }, { "text": "QCD string and the Lorentz nature of confinement: We address the question of the Lorentz nature of the effective long-range\ninterquark interaction generated by the QCD string with quarks at the ends.\nStudying the Dyson-Schwinger equation for a heavy-light quark-antiquark system,\nwe demonstrate explicitly how a Lorentz-scalar interaction appears in the\nDiraclike equation for the light quark, as a consequence of chiral symmetry\nbreaking. We argue that the effective interquark interaction in the Hamiltonian\nof the QCD string with quarks at the ends stems from this effective scalar\ninteraction.", "category": "hep-ph" }, { "text": "Challenges and Opportunities for the Next Generation of Photon\n Regeneration Experiments: Photon regeneration experiments searching for signatures of oscillations of\nphotons into hypothetical very weakly interacting ultra-light particles, such\nas axions, axion-like and hidden-sector particles, have improved their\nsensitivity considerably in recent years. Important progress in laser and\ndetector technology as well as recycling of available magnets from accelerators\nmay allow a big further step in sensitivity such that, for the first time,\nlaser light shining through a wall experiments will explore territory in\nparameter space that has not been excluded yet by astrophysics and cosmology.\nWe review these challenges and opportunities for the next generation\nexperiments.", "category": "hep-ph" }, { "text": "The Infrared Behavior of One-Loop Gluon Amplitudes at\n Next-to-Next-to-Leading Order: For the case of $n$-jet production at next-to-next-to-leading order in the\nQCD coupling, in the infrared divergent corners of phase space where particles\nare collinear or soft, one must evaluate $(n+1)$-parton final-state one-loop\namplitudes through $\\Ord(\\eps^2)$, where $\\eps$ is the dimensional\nregularization parameter. For the case of gluons, we present to all orders in\n$\\eps$ the required universal functions which describe the behavior of one-loop\namplitudes in the soft and collinear regions of phase space. An explicit\nexample is discussed for three-parton production in multi-Regge kinematics that\nhas applications to the next-to-leading logarithmic corrections to the BFKL\nequation.", "category": "hep-ph" }, { "text": "Physics of heavy neutrinos: Theoretical and experimental situation in physics of heavy neutrinos\n$(M_N>M_Z)$ is briefly presented. Various experimental bounds on heavy neutrino\nmasses and mixings are shortly reviewed. Special attention is paid to\npossibility of detecting heavy neutrinos in future lepton linear colliders.", "category": "hep-ph" }, { "text": "Small Shear Viscosity of a Quark-Gluon Plasma Implies Strong Jet\n Quenching: We derive an expression relating the transport parameter $\\hat{q}$ and the\nshear viscosity $\\eta$ of a weakly coupled quark-gluon plasma. A deviation from\nthis relation can be regarded as a quantitative measure of ``strong coupling''\nof the medium. The ratio $T^3/\\hat{q}$, where $T$ is the temperature, is a more\nbroadly valid measure of the coupling strength of the medium than $\\eta/s$,\nwhere $s$ denotes the entropy density. Different estimates of $\\hat{q}$ derived\nfrom existing RHIC data are shown to imply radically different structures of\nthe produced matter.", "category": "hep-ph" }, { "text": "Determination of the spectroscopic parameters of beauty-partners of\n $T_{cc}$ from QCD: Motivated by the recent discovery of a new tetra-quark $T_{cc}^+$ state with\ntwo charm quarks and two light quarks by LHCb collaboration, we calculate the\nspectroscopic parameters, namely, the mass and residues of beauty partners of\n$T_{cc}^+$ within QCD sum rules by using hadronic molecular $BB^*$ picture. The\nobtained results are compared with the predictions of different approaches in\nthe literature.", "category": "hep-ph" }, { "text": "First extraction of the scalar proton dynamical polarizabilities from\n real Compton scattering data: We present the first attempt to extract the scalar dipole dynamical\npolarizabilities from proton real Compton scattering data below pion-production\nthreshold. The theoretical framework combines dispersion relations technique,\nlow-energy expansion and multipole decomposition of the scattering amplitudes.\nThe results are obtained with statistical tools that have never been applied so\nfar to Compton scattering data and are crucial to overcome problems inherent to\nthe analysis of the available data set.", "category": "hep-ph" }, { "text": "Test for Lorentz and CPT Violation with the MiniBooNE Low-Energy Excess: The MiniBooNE experiment is a $\\nu_\\mu\\to\\nu_e$ and $\\bar\\nu_\\mu\\to\\bar\\nu_e$\nappearance neutrino oscillation experiment at Fermilab. The neutrino mode\noscillation analysis shows an excess of $\\nu_e$ candidate events in the\nlow-energy region. These events are analyzed under the SME formalism, utilizing\nthe short baseline approximation. The preliminary result shows the time\nindependent solution is favored. The relationship with the SME parameters\nextracted from the LSND experiment is discussed. The systematic error analysis\nand antineutrino mode analysis are outlined.", "category": "hep-ph" }, { "text": "Study of kaon structure using the light-cone quark model: We investigate the various distributions explaining multi-dimensional\nstructure of kaon at the level of its constituents ($u$ and $\\bar{s}$) using\nthe light-cone quark model. The overlap form of wavefunctions associated with\nthe light-cone quark model is adopted for the calculations. The generalized\nparton distributions(GPDs)of $u$ and $\\bar{s}$ quarks are presented for the\ncase when the momentum transfer in the longitudinal direction is non-zero. The\ndependence of kaon GPDs is studied in terms of variation of quark longitudinal\nmomentum fraction, momentum transfer in longitudinal direction and total\nmomentum transfer to the final state of hadron. The transverse impact-parameter\ndependent GPDs are also studied by taking the Fourier transformation of general\nGPDs. Further, the quantum phase-space distributions; Wigner distributions are\nstudied for the case of unpolarized, longitudinally-polarized and\ntransversely-polarized parton in an unpolarized kaon. The Wigner distributions\nare analysed in the transverse impact-parameter plane, the transverse momentum\nplane and the mixed plane. Further, to get a complete picture of kaon in terms\nof its valence quarks, the variation of longitudinal momentum fraction carried\nby quark and antiquark in the generalized transverse momentum-dependent parton\ndistributions (GTMDs) is studied for different values of transverse quark and\nantiquark momentum $({\\bf k}_\\perp)$ as well as for different values of\nmomentum transferred to the kaon in transverse direction $({\\bf\n\\Delta}_\\perp)$. This has been done for zero as well as non-zero skewedness\nrepresenting respectively the absence and presence of momentum transfer to the\nfinal state of kaon in longitudinal direction. Furthermore, the possible\nspin-orbit correlation for $u$ and $\\bar{s}$ in kaon is elaborated in context\nof Wigner distributions and GTMDs.", "category": "hep-ph" }, { "text": "Nuclear Structure Functions at Small x in Multiple Scattering Approaches: A simple model for nuclear structure functions in the region of small $x$ and\nsmall and moderate $Q^2$, is presented. It is a parameter-free extension, in\nthe Glauber-Gribov approach to nuclear collisions, of a saturation model for\nthe nucleon. A reasonable agreement with experimental data on ratios of nuclear\nstructure functions is obtained. The unintegrated gluon distribution and the\nbehavior of the saturation scale which result from this model are discussed.", "category": "hep-ph" }, { "text": "A Susy Phase Transition as Central Engine: For several decades the energy source powering supernovae and gamma ray\nbursts has been a troubling mystery. Many articles on these phenomena have been\ncontent to model the consequences of an unknown \"central engine\" depositing a\nlarge amount of energy in a small region. In the case of supernovae this is\nsomewhat unsettling since the type 1a supernovae are assumed to be\n\"standardizable candles\" from which important information concerning the dark\nenergy can be derived. It should be expected that a more detailed understanding\nof supernovae dynamics could lead to a reduction of the errors in this\nrelationship. Similarly, the current state of the standard model theory of\ngamma ray bursts, which in some cases have been associated with supernovae, has\nconceptual gaps not only in the central engine but also in the mechanism for\njet collimation and the lack of baryon loading. We discuss here the\nSupersymmetric (susy) phase transition model for the central engine.", "category": "hep-ph" }, { "text": "Stops in R-parity Breaking Model for High-$Q^2$ Events at HERA: We investigate an event excess in the reaction $e^+p \\to e^+ X$ with large\n$x$ and high $Q^2$ observed at HERA and show that the events could naturally be\ninterpreted as a signature of the production of the scalar top quarks (stops)\nin a supersymmetric model with $R$-parity breaking interactions. The HERA\nevents are characterized by the broad mass distribution and in fact it can be\nsimulated by our specific scenario if we consider almost degenerate two mass\neigenstates $\\tilde{t_1}$ and $\\tilde{t_2}$ of the stops.", "category": "hep-ph" }, { "text": "Heavy Quark State Production In p-p Collisions: We estimate the relative probabilities of $\\Psi'(2S)$ to $J/\\Psi$ production\nat BNL-RHIC and $\\Upsilon(nS)$ production at the LHC and Fermilab in p-p\ncollisions, using our recent theory of mixed heavy quark hybrids, in which the\n$\\Psi'(2S)$ and $\\Upsilon(3S)$ mesons have approximately equal normal\n$q\\bar{q}$ and hybrid $q\\bar{q}g$ components.", "category": "hep-ph" }, { "text": "Vector-scalar mixing to all orders, for an arbitrary gauge model in the\n generic linear gauge: I give explicit fromulae for full propagators of vector and scalar fields in\na generic spin-1 gauge model quantized in an arbitrary linear covariant gauge.\nThe propagators, expressed in terms of all-order one-particle-irreducible\ncorrelation functions, have a remarkably simple form because of constraints\noriginating from Slavnov-Taylor identities of Becchi-Rouet-Stora symmetry. I\nalso determine the behavior of the propagators in the neighborhood of the\npoles, and give a simple prescription for the coefficients that generalize (to\nthe case with an arbitrary vector-scalar mixing) the standard\n$\\sqrt{\\mathcal{Z}}$ factors of Lehmann, Symanzik and Zimmermann. So obtained\ngeneralized $\\sqrt{\\mathcal{Z}}$ factors, are indispensable to the correct\nextraction of physical amplitudes from the amputated correlation functions in\nthe presence of mixing. The standard $R_\\xi$ guauges form a particularly\nimportant subclass of gauges considered in this paper. While the tree-level\nvector-scalar mixing is, by construction, absent in $R_\\xi$ gauges, it\nunavoidably reappears at higher orders. Therefore the prescription for the\ngeneralized $\\sqrt{\\mathcal{Z}}$ factors given in this paper is directly\nrelevant for the extraction of amplitudes in $R_\\xi$ gauges.", "category": "hep-ph" }, { "text": "Benchmarking LHC searches for light 2HDM+$\\boldsymbol{a}$ pseudoscalars: Using two suitable benchmark scenarios that satisfy the experimental\nconstraints on the total decay width of the $125 \\, {\\rm GeV}$ Higgs boson, we\ndetermine the bounds on light CP-odd spin-0 states in the 2HDM+$a$ model that\narise from existing LHC searches. Our work represents the first thorough study\nthat considers the parameter space with $m_a \\lesssim 100 \\, {\\rm GeV}$ and\nshould prove useful for 2HDM+$a$ interpretations of future ATLAS, CMS and LHCb\nsearches for pseudoscalars with masses below the electroweak scale.", "category": "hep-ph" }, { "text": "Report of Working Group on Electromagnetic Corrections: The talks delivered by M. Knecht, H. Neufeld, V.E. Lyubovitskij, A. Rusetsky\nand J. Soto during the session of the working group of electromagnetic\ncorrections to hadronic processes at the Eight International Symposium MENU99,\ncover a wide range of problems. In particular, those include: construction of\nthe effective Lagrangians that then are used for the evaluation of\nelectromagnetic corrections to the decays of K mesons; evaluation of some of\nthe low-energy constants in these Lagrangians, using sum rules and the\nlarge-N_c arguments; complete calculations of electromagnetic corrections to\nthe pi pi scattering amplitude at O(e^2p^2); the general theory of\nelectromagnetic bound states of hadrons in the Standard Model.", "category": "hep-ph" }, { "text": "Physics with near detectors at a neutrino factory: We discuss the impact of near detectors at a neutrino factory both on\nstandard oscillation and non-standard interaction measurements. Our systematics\ntreatment includes cross section errors, flux errors, and background\nuncertainties, and our near detector fluxes include the geometry of the\nneutrino source and the detector. Instead of a specific detector concept, we\nintroduce qualitatively different classes of near detectors with different\ncharacteristics, such as near detectors catching the whole neutrino flux (near\ndetector limit) versus near detectors observing a spectrum similar to that of\nthe far detector (far detector limit). We include the low energy neutrino\nfactory in the discussion. We illustrate for which measurements near detectors\nare required, discuss how many are needed, and what the role of the flux\nmonitoring is. For instance, we demonstrate that near detectors are mandatory\nfor the leading atmospheric parameter measurements if the neutrino factory has\nonly one baseline, whereas systematical errors partially cancel if the neutrino\nfactory complex includes the magic baseline. Finally, near detectors with\nnu_tau detection are shown to be useful for non-standard interactions.", "category": "hep-ph" }, { "text": "Spectrum for Heavy Quankonia and Mixture of the Relevant Wave Functions\n within the Framework of Bethe-Salpeter Equation: Considering the fact that some excited states of the heavy quarkonia\n(charmonium and bottomonium) still missing in experimental observations and\npotential applications of the relevant wave functions of the bound states, we\nre-analyze the spectrum and the relevant wave functions of the heavy quarkonia\nwithin the framework of Bethe-Salpeter (B.S.) equation with a proper\nQCD-inspired kernel. Such a kernel for the heavy quarkonia, relating to\npotential of non-relativistic quark model, is instantaneous, so we call the\ncorresponding B.S. equation as BS-In equation throughout the paper.\nParticularly, a new way to solve the B.S. equation, which is different from the\ntraditional ones, is proposed here, and with it not only the known spectrum for\nthe heavy quarkonia is re-generated, but also an important issue is brought in,\ni.e., the obtained solutions of the equation `automatically' include the\n'fine', 'hyperfine' splittings and the wave function mixture, such as $S-D$\nwave mixing in $J^{PC}=1^{--}$ states, $P-F$ wave mixing in $J^{PC}=2^{++}$\nstates for charmonium and bottomonium etc. It is pointed out that the best\nplace to test the wave mixture probably is at $Z$-factory ($e^+e^-$ collider\nrunning at $Z$-boson pole with extremely high luminosity).", "category": "hep-ph" }, { "text": "Non linear evolution: revisiting the solution in the saturation region: In this paper we revisit the problem of the solution to Balitsky-Kovchegov\nequation deeply in the saturation domain. We find that solution has the form of\nLevin-Tuchin solution but it depends on variable $\\bar{z} = \\ln(r^2 Q^2_s) +\n\\mbox{Const}$ and the value of $\\mbox{Const}$ is calculated in this paper. We\npropose the solution for full BFKL kernel at large $z$ in the entire kinematic\nregion that satisfies the McLerram-Venugopalan initial condition", "category": "hep-ph" }, { "text": "Probing the neutrino mass matrix in next generation neutrino oscillation\n experiments: We review the current status of the neutrino mass and mixing parameters\nneeded to reconstruct the neutrino mass matrix. A comparative study of the\nprecision in the measurement of oscillation parameters expected from the next\ngeneration solar, atmospheric, reactor and accelerator based experiments is\npresented. We discuss the potential of $0\\nu\\beta\\beta$ experiments in\ndetermining the neutrino mass hierarchy and the importance of a better\n$\\theta_{12}$ measurement for it.", "category": "hep-ph" }, { "text": "Multi-jet Production in Hadron Collisions: The advent of high-energy hadron colliders necessitates efficient and\naccurate computation of multi-jet production processes, both as QCD processes\nin their own right and as backgrounds for other physics. The algorithm that\nperforms these tasks and a brief numerical study of multi-jet processes are\npresented.", "category": "hep-ph" }, { "text": "Soft spin correlations in final-state parton showers: We introduce a simple procedure that resolves the long-standing question of\nhow to account for single-logarithmic spin-correlation effects in parton\nshowers not just in the collinear limit, but also in the soft wide-angle limit,\nat leading colour. We discuss its implementation in the context of the\nPanScales family of parton showers, where it complements our earlier treatment\nof the purely collinear spin correlations. Comparisons to fixed-order matrix\nelements help validate our approach up to third order in the strong coupling,\nand an appendix demonstrates the small size of residual subleading-colour\neffects. To help probe wide-angle soft spin correlation effects, we introduce a\nnew declustering-based non-global spin-sensitive observable, the first of its\nkind. Our showers provide a reference for its single-logarithmic resummation.\nThe work in this paper represents the last step required for final-state\nmassless showers to satisfy the broad PanScales next-to-leading logarithmic\naccuracy goals.", "category": "hep-ph" }, { "text": "Non-abelian color dielectric - towards the effective model of the low\n energy QCD: Lattice motivated triplet color scalar field theory is analyzed. We consider\nnon-minimal as well as covariant derivative coupling with SU(2) gauge fields.\nField configurations generated by external electric sources are presented.\nMoreover non-Abelian magnetic monopoles are found. Dependence on the spatial\ncoordinates in the obtained solutions is identical as in the usual Abelian\ncase. We show also that after a decomposition of the fields a modified\nFaddeev-Niemi action can be obtained. It contains explicit O(3) symmetry\nbreaking term parameterized by the condensate of an isoscalar field. Due to\nthat Goldstone bosons observed in the original Faddeev-Niemi model are removed.", "category": "hep-ph" }, { "text": "Lambda(1520) photoproduciton off the proton target with Regge\n contributions: We investigate the Lambda(1520,3/2^-)=Lambda* photoproduction off the proton\ntarget with the Regge contributions to go beyond the resonance region, in\naddition to the tree-level Born terms consisting of the s, t, and u channels,\nand contact term. For this purpose, the Reggeized propagators for the K and K*\nexchanges in the t channel are employed in a gauge-invariant manner. We also\ntake into account the contribution from a nucleon resonance D_{13}(2030). We\ncompute the angular and energy dependences of the production process, including\npolarization observables, such as the photon-beam asymmetry and the\npolarization-transfer coefficients, resulting in good qualitative agreement\nwith current experimental data. It turns out that the Regge contributions are\nnecessary to explain the high-energy data beyond E_{gamma}~4 GeV especially for\nthe angular dependences in the forward-scattering region. On the contrary, the\npolarization observables are insensitive to the Regge contributions due to the\ncontact-term dominance and gauge invariance. We also compute the K^{-}-angle\ndistribution function in the Gottfried-Jackson frame, using the\npolarization-transfer coefficients in the z direction. It shows nontrivial\ntheta and E_{gamma} dependences in the forward-scattering region.", "category": "hep-ph" }, { "text": "Precision Theory of Electroweak Interactions: As a part of the celebration of 50 years of the Standard Model of particle\nphysics, I present a brief history of the precision theory of electroweak\ninteractions. I emphasize in particular the theoretical preparations for the\nLEP program and the prediction of m_t and m_h from the electroweak precision\ndata. [to appear in the proceedings of the SM@50 Symposium, Case Western\nReserve University, June 1-4, 2018]", "category": "hep-ph" }, { "text": "Bounds on TeV Seesaw Models from LHC Higgs Data: We derive bounds on the Dirac Yukawa couplings of the neutrinos in seesaw\nmodels using the recent Large Hadron Collider (LHC) data on Higgs decays for\nthe case where the Standard Model singlet heavy leptons needed for the seesaw\nmechanism have masses in the 100 GeV range. Such scenarios with large Yukawa\ncouplings are natural in Inverse Seesaw models since the small neutrino mass\nowes its origin to a small Majorana mass of a new set of singlet fermions.\nLarge Yukawas with sub-TeV mass right-handed neutrinos are also possible for\ncertain textures in Type-I seesaw models, so that the above bounds also apply\nto them. We find that the current Higgs data from the LHC can put bounds on\nboth electron- and muon-type Yukawa couplings of order 10^{-2}.", "category": "hep-ph" }, { "text": "Delicate interplay between the D0-D*0, rho0-J/psi, and omega-J/psi\n channels in the X(3872) resonance: The nature of the X(3872) enhancement is analysed in the framework of the\nResonance-Spectrum Expansion, by studying it as a regular $J^{PC}=1^{++}$\ncharmonium state, though strongly influenced and shifted by open-charm decay\nchannels. The observed but Okubo-Zweig-Iizuka-forbidden $\\rho^0 J/\\psi$ and\n$\\omega J/\\psi$ channels are coupled as well, but effectively smeared out by\nusing complex $\\rho^0$ and $\\omega$ masses, in order to account for their\nphysical widths, followed by a rigorous algebraic procedure to restore\nunitarity. A very delicate interplay between the $D^0 D^{*0}$, $\\rho^0 J/\\psi$,\nand $\\omega J/\\psi$ channels is observed. The data clearly suggest that the\nX(3872) is a very narrow axial-vector $c\\bar{c}$ resonance, with a pole at or\nslightly below the $D^0D^{*0}$ threshold.", "category": "hep-ph" }, { "text": "High-p_T Pion Quenching versus anti+Baryon Enhancement in\n Nucleus-Nucleus Collisions: Jet quenching of quarks and gluons in central A+A collisions suppresses the\nhigh-p_T meson production and exposes novel baryon dynamics that we attribute\nto (gluonic) baryon junctions. This mechanism predicts baryon enhancement in a\nfinite moderate-p_T window that decreases with increasing impact parameter. We\nalso extend recent calculations of the transverse momentum behavior of p/pi^+\nand p-bar/pi^- to other baryon species and show that a similar pattern is\nexpected for the K^-/Lambda and K^+/bar{Lambda} ratios. Within the framework of\nthe model constant p-bar/p and bar{Lambda}/Lambda ratios are found in central\nAu+Au collisions at RHIC energies up to p_T ~= 4 - 5 GeV.", "category": "hep-ph" }, { "text": "High-energy neutrino deeply inelastic scattering cross sections from 100\n GeV to 1000 EeV: We present a state-of-the-art prediction for cross sections of neutrino\ndeeply inelastic scattering (DIS) from nucleon at high neutrino energies,\n$E_\\nu$, from 100 GeV to 1000 EeV ($10^{12}$ GeV). Our calculations are based\non the latest CT18 NNLO parton distribution functions (PDFs) and their\nassociated uncertainties. In order to make predictions for the highest\nenergies, we extrapolate the PDFs to small $x$ according to several procedures\nand assumptions, thus affecting the uncertainties at ultra-high $E_\\nu$; we\nquantify the uncertainties corresponding to these choices. Similarly, we\nquantify the uncertainties introduced by the nuclear corrections which are\nrequired to evaluate neutrino-nuclear cross sections for neutrino telescopes.\nThese results can be applied to currently-running astrophysical neutrino\nobservatories, such as IceCube, as well as various future experiments which\nhave been proposed.", "category": "hep-ph" }, { "text": "A proposal for improving the hadronization of QCD currents in TAUOLA: After overviewing the general features of semileptonic decays of the tau\nlepton, I will recall the most widely used model for them, namely that of\nKuhn-Santamaria (KS), and I will explain the subsequent works that were done\nalong these lines and that are implemented in the TAUOLA library for analysing\ntau decays. After that, I will move to the description of our project that aims\nto achieve a theory as close as possible to QCD for the considered decays. I\nconclude by emphasizing the importance of the implementation of our work in\nTAUOLA.", "category": "hep-ph" }, { "text": "The $\u0394S=1$ Effective Hamiltonian Including Next-to-Leading Order\n QCD and QED Corrections: In this paper we present a calculation of the $\\Delta S=1$ effective weak\nHamiltonian including next-to-leading order QCD and QED corrections. At a scale\n$\\mu$ of the order of few GeV, the Wilson coefficients of the operators are\ngiven in terms of the renormalization group evolution matrix and of the\ncoefficients computed at a large scale $\\sim M_W$. The expression of the\nevolution matrix is derived from the two-loop anomalous dimension matrix which\ngoverns the mixing of the relevant current-current and penguin operators,\nrenormalized in some given regularization scheme. We have computed the\nanomalous dimension matrix up to and including order $\\alphas^2$ and $\\alphae\n\\alphas$ in two different renormalization schemes, NDR and HV, with consistent\nresults. We give many details on the calculation of the anomalous dimension\nmatrix at two loops, on the determination of the Wilson coefficients at the\nscale $M_W$ and of their evolution from $M_W$ to $\\mu$. We also discuss the\ndependence of the Wilson coefficients/operators on the regularization scheme.", "category": "hep-ph" }, { "text": "Neutral pion decay in dense skyrmion matter: We study the density dependence of the decay $\\pi^0\\to \\gamma \\gamma$ using\nthe Skyrme Lagrangian to describe simultaneously both the matter background and\nmesonic fluctuations. Pion properties such as mass and decay constant are\nmodified by the medium. This leads to large suppression at high density of both\nphoto-production from the neutral pion and the reverse process. The in-medium\neffective charge of $\\pi^{\\pm}$ are also discussed in the same framework.", "category": "hep-ph" }, { "text": "One-Loop N Gluon Amplitudes with Maximal Helicity Violation via\n Collinear Limits: We present a conjecture for the $n$-gluon one-loop amplitudes with maximal\nhelicity violation. The conjecture emerges from the powerful requirement that\nthe amplitudes have the correct behavior in the collinear limits of external\nmomenta. One implication is that the corresponding amplitudes where three or\nmore gluon legs are replaced by photons vanish for $n>4$.", "category": "hep-ph" }, { "text": "Heavy-flavor effects in soft gluon resummation for electroweak boson\n production at hadron colliders: We evaluate the impact of heavy-quark masses on transverse momentum\ndistributions of W, Z, and supersymmetric neutral Higgs bosons at the Tevatron\nand LHC. The masses of charm and bottom quarks act as non-negligible momentum\nscales at small transverse momentum, and affect resummation of soft and\ncollinear radiation. We point out inconsistencies in the treatment of\nheavy-flavor channels at small transverse momentum in massless factorization\nschemes, and formulate small transverse momentum resummation in a general-mass\nvariable flavor number factorization scheme. The improved treatment of the\nquark mass dependence leads to non-negligible effects in precision measurements\nof the W boson mass at the LHC, and may cause observable modifications in\nproduction of Higgs bosons and other particles in heavy-quark scattering.", "category": "hep-ph" }, { "text": "Beam polarization effects on top-pair production at the ILC: Full one-loop electroweak-corrections for an $e^-e^+\\rightarrow t \\bar{t}$\nprocess associated with sequential $t\\rightarrow b \\mu\\nu_\\mu$ decay are\ndiscussed. At the one-loop level, the spin-polarization effects of the initial\nelectron and positron beams are included in the total and differential cross\nsections. A narrow-width approximation is used to treat the top-quark\nproduction and decay while including full spin correlations between them. We\nobserved that the radiative corrections due to the weak interaction have a\nlarge polarization dependence on both the total and differential cross\nsections. Therefore, experimental observables that depend on angular\ndistributions such as the forward-backward asymmetry of the top production\nangle must be treated carefully including radiative corrections. We also\nobserved that the energy distribution of bottom quarks is majorly affected by\nthe radiative corrections.", "category": "hep-ph" }, { "text": "Electroweak Physics at HERA: Introduction and Summary: A high luminosity upgrade of HERA will allow the measurement of standard\nmodel parameters and the neutral current couplings of quarks. These results\nwill have to be consistent with other precision measurements or indicate traces\nof new physics. The analysis of $W$ production will complement future results\nof LEP 2 and the Tevatron. We summarize the main results and conclusions\nobtained by the working group on Electroweak Physics concerning the potential\nof future experimentation at HERA.", "category": "hep-ph" }, { "text": "New light on WW scattering at the LHC with W jet tagging: After the recent discovery of a 125 GeV Higgs-like particle at the Large\nHadron Collider (LHC), it is crucial to examine its role in unitarizing high\nenergy W_LW_L scattering, which may reveal its possible deviation from a\nStandard Model Higgs. We perform an updated study on WW scattering in the\nsemileptonic channel at the LHC, improved by the recently developed W jet\ntagging method. The resultant statistical significance of a\nStrongly-Interacting Light Higgs (SILH) model is about 20% larger than that\nbased on the conventionally \"gold-plated\" dileptonic channel, while 200% more\nsignal events are retained. This allows the discovery of an SILH model if the\nsignal strength is 100% (10%) of a pure Higgsless model, using about 40 (3000)\nfb^{-1} data at the 14 TeV LHC. Meanwhile, the excellent sensitivity to the\nanomalous Higgs-W boson coupling makes semileptonic WW scattering an important\ncomplement to precision measurements at the Higgs resonance.", "category": "hep-ph" }, { "text": "Probing Majorana neutrinos in rare K and D, D_s, B, B_c meson decays: We study lepton number violating decays of charged K, D, D_s, B and B_c\nmesons of the form M^+\\to {M'}^-\\ell^+\\ell^+, induced by the existence of\nMajorana neutrinos. These processes provide information complementary to\nneutrinoless double nuclear beta decays, and are sensitive to neutrino masses\nand lepton mixing. We explore neutrino mass ranges m_N from below 1 eV to\nseveral hundred GeV. We find that in many cases the branching ratios are\nprohibitively small, however in the intermediate range m_\\pi < m_N < m_{B_c},\nin specific channels and for specific neutrino masses, the branching ratios can\nbe at the reach of high luminosity experiments like those at the LHC-b and\nfuture Super flavor-factories, and can provide bounds on the lepton mixing\nparameters.", "category": "hep-ph" }, { "text": "Structures of Neutrino Flavor Mixing Matrix and Neutrino Oscillations at\n CHORUS and NOMAD: We have studied structures of the neutrino flavor mixing matrix focusing on\nthe neutrino oscillations at CHORUS and NOMAD as well as the one at LSND(or\nKARMEN). We have assumed two typical neutrino mass hierarchies $m_3\\simeq\nm_2\\gg m_1$ and $m_3\\gg m_2\\gg m_1({\\rm or}\\simeq m_1)$. Taking into account\nthe see-saw mechanism of neutrino masses, the reasonable neutrino flavor mixing\npatterns have been discussed. The observation of the neutrino oscillation at\nCHORUS and NOMAD presents us the important constraint for the structure of the\nneutrino flavor mixing matrix. The atomospheric neutrino anomaly has been\ndiscussed in relation to the CHORUS and NOMAD experiments.", "category": "hep-ph" }, { "text": "An analysis of Precision Electroweak Measurements: Summer 98 Update: We update our analysis of precision electroweak measurements using the latest\ndata announced at Moriond, March 1998. Possible oblique corrections from new\nphysics are parametrized using the STU formalism of Ref.[1], and non-oblique\ncorrections to the Zbb vertex are parametrized using the xi_b zeta_b formalism\nof Ref.[2]. The implications of the analysis on minimal SU(5) grand unification\nis discussed.", "category": "hep-ph" }, { "text": "Progress in the Theory of the Electroweak Phase Transition: Recent progress in the theory of the electroweak phase transition is\ndiscussed. For the Higgs boson mass smaller than the masses of W and Z bosons,\nthe phase transition is of the first order. However, its strength is\napproximately 2/3 times less than what follows from the one-loop approximation.\nThis rules out baryogenesis in the minimal version of the electroweak theory\nwith light Higgs bosons. The possibility of the strongly first order phase\ntransition in the theory with superheavy Higgs bosons is considered.\n We show that if the Yang-Mills field at high temperature acquires a magnetic\nmass $\\sim g^2 T$, then no linear terms appear in the effective potential in\nall orders of perturbation theory and the symmetry in gauge theories at high\ntemperatures is actually restored. Even though the last statement was never\nquestioned by most of the authors, it was extremely difficult to come to a\nreliable conclusion about it due to the infrared problem in thermodynamics of\nnon-Abelian gauge fields.\n The phase transition occurs due to production and expansion of critical\nbubbles. A general analytic expression for the probability of the bubble\nformation is obtained, which may be used for study of tunneling in a wide class\nof theories.", "category": "hep-ph" }, { "text": "Reconciling the nonrelativistic QCD prediction and the $J/\u03c8\\to\n 3\u03b3$ data: It has been a long-standing problem that the rare electromagnetic decay\nprocess $J/\\psi\\to 3\\gamma$ is plagued with both large and negative radiative\nand relativistic corrections. To date it remains futile to make a definite\nprediction to confront with the branching fraction of $J/\\psi\\to 3\\gamma$\nrecently measured by the \\textsf{CLEO-c} and \\textsf{BESIII} Collaborations. In\nthis work, we investigate the joint perturbative and relativistic correction\n(i.e. the ${\\mathcal O}(\\alpha_s v^2)$ correction, where $v$ denotes the\ncharacteristic velocity of the charm quark inside the $J/\\psi$) for this decay\nprocess, which turns out to be very significant. After incorporating the\ncontribution from this new ingredient, with the reasonable choice of the input\nparameters, we are able to account for the measured decay rates in a\nsatisfactory degree.", "category": "hep-ph" }, { "text": "MSSM Constraints from Higgs Boson Searches: The LEP era has brought immense progress in searches for Higgs bosons over\nthe last 12 years which will guide searches at future colliders. The evolution\nof the Higgs boson mass limits are reviewed with the focus on results from\ngeneral parameter scans in the Minimal Supersymmetric extension of the Standard\nModel (MSSM) in contrast to the so-called benchmark limits. The hint for a\nStandard Model (SM) Higgs boson of 115.6 GeV can also be interpreted as a\npreference for a Higgs boson of that mass in the MSSM. Further small data\nexcesses allow the hypothesis that the neutral Higgs bosons of the MSSM all\nhave masses between 90 and 116 GeV.", "category": "hep-ph" }, { "text": "Classical Gluon Production Amplitude for Nucleus-Nucleus Collisions:\n First Saturation Correction in the Projectile: We calculate the classical single-gluon production amplitude in\nnucleus-nucleus collisions including the first saturation correction in one of\nthe nuclei (the projectile) while keeping multiple-rescattering (saturation)\ncorrections to all orders in the other nucleus (the target). In our\napproximation only two nucleons interact in the projectile nucleus: the\nsingle-gluon production amplitude we calculate is order-g^3 and is\nleading-order in the atomic number of the projectile, while resumming all\norder-one saturation corrections in the target nucleus. Our result is the first\nstep towards obtaining an analytic expression for the first projectile\nsaturation correction to the gluon production cross section in nucleus-nucleus\ncollisions.", "category": "hep-ph" }, { "text": "The Simplest Models of Radiative Neutrino Mass: Excluding Simplified Zee\n Models and Beyond: The complexity of radiative neutrino-mass models can be judged by: (i)\nwhether they require the imposition of ad hoc symmetries, (ii) the number of\nnew multiplets they introduce, and (iii) the number of arbitrary parameters\nthat appear. Adopting the view that the imposition of arbitrary new symmetries\nis the least appealing approach, the simplest models have two new multiplets\nand a minimal number of new parameters. With this in mind, we search for the\nsimplest models of radiative neutrino mass. We are lead to two new models,\ncontaining a real scalar triplet and a charged scalar doublet (respectively),\nin addition to the charged singlet scalar considered by Zee [h^+\\sim(1,1,2)].\nThe new models are essentially simplified versions of the Zee model and appear\nto be \\emph{the simplest} models of radiative neutrino mass. However, these\nmodels are only of pedagogical interest; despite successfully generating\nnonzero masses, present-day data is sufficient to rule them out. The lessons\nlearned from these models also enable one to exclude a more general class of\nradiative models. Moving beyond the minimal cases, we find a new model of\ntwo-loop masses that employs the charged doublet \\Phi\\sim(1,2,3) and the\ndoubly-charged scalar k^{++}\\sim(1,1,4).", "category": "hep-ph" }, { "text": "Curvature Perturbation from Supersymmetric Flat Directions: We show that a contribution to the total curvature perturbation may be due to\nthe presence of flat directions in supersymmetric models. It is generated at\nthe first os- cillation of the flat direction condensate when the latter\nrelaxes to the minimum of its potential after the end of inflation. We also\npoint out that, if the contribution to the total curvature perturbation from\nsupersymmetric flat direction is the dominant one, then a significant level of\nnon-Gaussianity in the cosmological perturbation is also naturally expected.", "category": "hep-ph" }, { "text": "QCD correction to gluino decay to $t\\bar{t}\\tilde\u03c7^0_1$ in the MSSM: We calculate the complete next-to-leading order QCD corrections to the\nthree-body decay of gluino into top-pair associated with a lightest neutralino\nin the minimal supersymmetric standard model. We obtain that the LO and NLO QCD\ncorrected decay widths of $\\tilde{g} \\to t \\bar{t} \\tilde{\\chi}_1^0$ at the\n${\\rm SPS 6}$ benchmark point are $0.1490 GeV$ and 0.1069 GeV respectively, and\nthe relative correction is -28.2%. We investigate the dependence of the QCD\ncorrection to $\\tilde{g} \\to t \\bar{t} \\tilde{\\chi}_1^0$ on $\\tan\\beta$ and the\nmasses of gluino, scalar top quarks and the lightest neutralino around the\n${\\rm SPS6}$ benchmark point, separately. We find that the NLO QCD corrections\nsuppress the LO decay width, and the absolute relative correction can exceed\n30% in some parameter space. Therefore, the QCD corrections to the three-body\ndecay $\\tilde{g} \\to t\\bar{t}\\tilde{\\chi}^0_1$ should be taken into account for\nthe precise experimental measurement at future colliders. Moreover, we study\nthe distributions of the top-pair invariant mass ($M_{t\\bar t}$) and the\nmissing energy ($E^{miss}$), and find that the line shapes of the LO\ndistributions of $M_{t\\bar t}$ and $E^{miss}$ are not obviously distorted by\nthe NLO QCD corrections.", "category": "hep-ph" }, { "text": "Consistency of Gauged Two Higgs Doublet Model: Gauge Sector: We study the constraints on the new parameters in the gauge sector of gauged\ntwo Higgs doublet model using the electroweak precision test data collected\nfrom the Large Electron Positron Collider (LEP) at and off the Z-pole as well\nas the current Drell-Yan and high-mass dilepton resonance data from the Large\nHadron Collider (LHC). Impacts on the new parameters by the projected\nsensitivities of various electroweak observables at the Circular Electron\nPositron Collider (CEPC) proposed to be built in China are also discussed. We\nalso clarify why the St\\\"{u}eckelberg mass $M_Y$ for the hypercharge $U(1)_Y$\nis set to be zero in the model by showing that it would otherwise lead to the\nviolation of the standard charge assignments for the elementary quarks and\nleptons.", "category": "hep-ph" }, { "text": "Wandzura-Wilczek approximation for the twist-3 DVCS amplitude: We present a derivation of Wandzura-Wilczek (WW) like relations for skewed\nparton distributions. It is demonstrated for photon-pion scattering that the\nskewed twist-3 parton distributions contributing to the DVCS amplitude have\ndiscontinuities at the points $x=\\pm\\xi$ in the WW approximation. This may lead\nto a violation of factorisation for the twist-3 DVCS amplitude with transverse\npolarization of the virtual photon. We show, however, that the contribution of\nthe divergencies to the scattering of a transversely polarized virtual photon\naffects DVCS observables only at order $1/Q^2$ and can be neglected at twist-3\naccuracy. For the scattering of a longitudinally polarized photon the twist-3\namplitude is free of such divergencies.", "category": "hep-ph" }, { "text": "New effective treatment of the light-front nonvalence contribution in\n timelike exclusive processes: We discuss a necessary nonvalence contribution in timelike exclusive\nprocesses. Following a Schwinger-Dyson type of approach, we relate the\nnonvalence contribution to an ordinary light-front wave function that has been\nextensively tested in the spacelike exclusive processes. A complicate four-body\nenergy denominator is exactly cancelled in summing the light-front time-ordered\namplitudes. Applying our method to $K_{\\ell3}$ and $D^0\\to K^- \\ell^+ \\nu_l$\nwhere a rather substantial nonvalence contribution is expected, we find not\nonly an improvement in comparing with the experimental data but also a\ncovariance(i.e. frame-independence) of existing light-front constituent quark\nmodel.", "category": "hep-ph" }, { "text": "Relic neutrino asymmetries and big bang nucleosynthesis in a four\n neutrino model: Oscillations between ordinary and sterile neutrinos can generate large\nneutrino asymmetries in the early universe. These asymmetries can significantly\naffect big bang nucleosynthesis (BBN) through modification of nuclear reaction\nrates. We study this phenomenon within a model consisting of the three ordinary\nneutrinos plus one sterile neutrino that can be motivated by the neutrino\nanomalies and the dark matter problem. We calculate how the lepton asymmetries\nproduced evolve at temperatures where they impact on BBN. The effect of the\nasymmetries on primordial helium production is determined, leading to an\neffective number of neutrino flavours during BBN of either about 2.7 or 3.1\ndepending on the sign of the lepton asymmetry.", "category": "hep-ph" }, { "text": "Gauge dependence of the quark gap equation: an exploratory study: We study the gauge dependence of the quark propagator in quantum\nchromodynamics by solving the gap equation with a nonperturbative quark-gluon\nvertex which is constrained by longitudinal and transverse Slavnov-Taylor\nidentities, the discrete charge conjugation and parity symmetries and which is\nfree of kinematic singularities in the limit of equal incoming and outgoing\nquark momenta. We employ gluon propagators in renormalizable $R_\\xi$ gauges\nobtained in lattice QCD studies. We report the dependence of the\nnonperturbative quark propagator on the gauge parameter, in particular we\nobserve an increase, proportional to the gauge-fixing parameter, of the mass\nfunction in the infrared domain, whereas the wave renormalization decreases\nwithin the range $0 \\leq \\xi \\leq 1$ considered here. The chiral quark\ncondensate reveals a mild gauge dependence in the region of $\\xi$ investigated.\nWe comment on how to build and improve upon this exploratory study in future in\nconjunction with generalized gauge covariance relations for QCD.", "category": "hep-ph" }, { "text": "The LPM Effect in sequential bremsstrahlung: $1/N_c^2$ corrections: An important question concerning in-medium high-energy parton showers in a\nquark-gluon plasma or other QCD medium is whether consecutive splittings of the\npartons in a given shower can be treated as quantum mechanically independent,\nor whether the formation times for two consecutive splittings instead have\nsignificant overlap. Various previous calculations of the effect of overlapping\nformation times have either (i) restricted attention to a soft bremsstrahlung\nlimit, or else (ii) used the large-$N_c$ limit (where $N_c{=}3$ is the number\nof quark colors). In this paper, we make a first study of the accuracy of the\nlarge-$N_c$ limit used by those calculations of overlap effects that avoid a\nsoft bremsstrahlung approximation. Specifically, we calculate the $1/N_c^2$\ncorrection to previous $N_c{=}\\infty$ results for overlap $g \\to gg \\to ggg$ of\ntwo consecutive gluon splittings $g \\to gg$. At order $1/N_c^2$, there is\ninteresting and non-trivial color dynamics that must be accounted for during\nthe overlap of the formation times.", "category": "hep-ph" }, { "text": "Forward Compton Scattering, using Real Analytic Amplitudes: We analyze forward Compton scattering, using real analytic amplitudes. By\nfitting the total \\gamma p scattering cross section data in the high energy\nregion 5 GeV < \\sqrt s < 20 GeV, using a cross section rising as \\ln^2 s, we\ncalculate \\rho_{\\gamma p}, the ratio of the real to the imaginary portion of\nthe the forward Compton scattering amplitude, and compare this to \\rho_{nn},\nthe ratio of the even portions of the pp and p-bar p forward scattering\namplitudes. We find that the two \\rho-values are, within errors, the same in\nthe c.m.s. energy region 5 GeV < \\sqrt s < 200 GeV, as predicted by a\nfactorization theorem of Block and Kadailov.", "category": "hep-ph" }, { "text": "The production of the doubly charmed baryon in deeply inelastic $ep$\n scattering at the Large Hadron Electron Collider: In this paper, we carry out a detailed study on the production of the doubly\ncharmed baryon in deeply inelastic $ep$ scattering (DIS) for $Q^2\\in[2,\n100]~\\textrm{GeV}^2$, at the Large Hadron Electron Collider (LHeC) with\n$E_e=60(140)$ GeV and $E_p=7000$ GeV. To exclude the contributions from the\ndiffractive productions and the $b$ hadron decays, we impose the kinematic cuts\n$0.31~\\textrm{GeV}^2$ in the\ncenter-of-mass (CM) frame of $\\gamma^{*}p$. Based on the designed LHeC\nluminosity, by detecting the decay channel $\\Xi^{+}_{cc}(\\Xi^{++}_{cc}) \\to\n\\Lambda_c^{+}$ with the subsequent decay $\\Lambda_c^{+} \\to pK^{-}\\pi^{+}$, we\npredict that about 1880 (2700) $\\Xi^{+}_{cc}$ events and 3750 (5400)\n$\\Xi^{++}_{cc}$ events can be accumulated per year, which signifies the\nprospect of observing them via the DIS at the forthcoming LHeC. In addition, we\nalso predict the distributions of a rich variety of physical observables in the\nlaboratory frame and the $\\gamma^{*}p$ CM frame, including $Q^2$, $p_t^{2}$,\n$Y$(rapidity), $p_t^{\\star2}$, $Y^{\\star}$, $W$, and $z$ distributions,\nrespectively, which can provide helpful references for studying the doubly\ncharmed baryon. In conclusion, we think that in addition to the LHC, the LHeC\nis also a helpful platform for studying the properties of the doubly charmed\nbaryon.", "category": "hep-ph" }, { "text": "Master Integrals for Inclusive Weak Decays of Heavy Flavours at\n Next-to-Leading Order: We present analytical results for master integrals emerging in the\ncomputation of differential rates for inclusive weak decays of heavy flavors at\nnext-to-leading order (NLO) in QCD. As an immediate physical application, these\nmaster integrals allow for a calculation of the spectra of the leptonic\ninvariant mass in inclusive semileptonic decays in the framework of the heavy\nquark expansion, including the NLO QCD corrections to power suppressed terms.", "category": "hep-ph" }, { "text": "Elastic and transition form factors of light pseudoscalar mesons from\n QCD sum rules: We revisit $F_\\pi(Q^2)$ and $F_{P\\gamma}(Q^2)$, $P=\\pi,\\eta,\\eta'$, making\nuse of the local-duality (LD) version of QCD sum rules. We give arguments, that\nthe LD sum rule provides reliable predictions for these form factors at $Q^2\n\\ge 5-6$ GeV$^2$, the accuracy of the method increasing with $Q^2$ in this\nregion. For the pion elastic form factor, the well-measured data at small $Q^2$\ngive a hint that the LD limit may be reached already at relatively low values\nof momentum transfers, $Q^2\\approx 4-8$ GeV$^2$; we therefore conclude that\nlarge deviations from LD in the region $Q^2=20-50$ GeV$^2$ seem very unlikely.\nThe data on the ($\\eta,\\eta')\\to\\gamma\\gamma^*$ form factors meet the\nexpectations from the LD model. However, the {\\sc BaBar} results for the\n$\\pi^0\\to\\gamma\\gamma^*$ form factor imply a violation of LD growing with $Q^2$\neven at $Q^2\\approx 40$ GeV$^2$, at odds with the $\\eta,\\eta'$ case and with\nthe general properties expected for the LD sum rule.", "category": "hep-ph" }, { "text": "Higher Twist Distribution Amplitudes of the Nucleon in QCD: We present the first systematic study of higher-twist light-cone distribution\namplitudes of the nucleon in QCD. We find that the valence three-quark state is\ndescribed at small transverse separations by eight independent distribution\namplitudes. One of them is leading twist-3, three distributions are twist-4 and\ntwist-5, respectively, and one is twist-6. A complete set of distribution\namplitudes is constructed, which satisfies equations of motion and constraints\nthat follow from conformal expansion. Nonperturbative input parameters are\nestimated from QCD sum rules.", "category": "hep-ph" }, { "text": "Baryon number non-conservation as Peccei-Quinn mechanism: Baryon number is an accidental symmetry in the standard model, while\nPeccei-Quinn symmetry is hypothetical symmetry which is introduced to solve the\nstrong CP problem. We study the possible connections between Peccei-Quinn\nsymmetry and baryon number symmetry. In this framework, an axion is identified\nas the Nambu-Goldstone boson of baryon number violation. As a result,\ncharacteristic baryon number violating processes are predicted. We developed\nthe general method to determine the baryon number and lepton number of new\nscalar in the axion model.", "category": "hep-ph" }, { "text": "The Electroweak Phase Transition at $m_H \\simeq m_W$: We study the finite temperature electroweak transition with non-perturbative\nlattice Monte Carlo simulations. We find that it is of first order, at least\nfor Higgs masses up to 80 GeV. The critical temperature of the phase transition\nis found to be smaller than that determined by a 2-loop renormalization group\nimproved effective potential. The jump of the order parameter at the critical\ntemperature is considerably larger than the perturbative value. By comparing\nlattice data and perturbation theory, we demonstrate that the latter, for the\ncomputation of the vacuum expectation value of the Higgs field $v(T)$ in the\nbroken phase at given temperature, converges quite well, provided $v(T)/T>1$.\nAn upper bound on the Higgs mass necessary for electroweak baryogenesis in the\nlight of the lattice data is briefly discussed.", "category": "hep-ph" }, { "text": "Higgs-gauge unification without tadpoles: In orbifold gauge theories localized tadpoles can be radiatively generated at\nthe fixed points where U(1) subgroups are conserved. If the Standard Model\nHiggs fields are identified with internal components of the bulk gauge fields\n(Higgs-gauge unification) in the presence of these tadpoles the Higgs mass\nbecomes sensitive to the UV cutoff and electroweak symmetry breaking is\nspoiled. We find the general conditions, based on symmetry arguments, for the\nabsence/presence of localized tadpoles in models with an arbitrary number of\ndimensions D. We show that in the class of orbifold compactifications based on\nT^{D-4}/Z_N (D even, N>2) tadpoles are always allowed, while on T^{D-4}/\\mathbb\nZ_2 (arbitrary D) with fermions in arbitrary representations of the bulk gauge\ngroup tadpoles can only appear in D=6 dimensions. We explicitly check this with\none- and two-loops calculations", "category": "hep-ph" }, { "text": "Scalar field couplings to quadratic curvature and decay into gravitons: Any field, even if it lives in a completely hidden sector, interacts with the\nvisible sector at least via the gravitational interaction. In this paper, we\nshow that a scalar field in such a hidden sector generically couples to the\nquadratic curvature via dimension five operators, i.e., $\\phi R^2$, $\\phi\nR^{\\mu\\nu} R_{\\mu\\nu}$, $\\phi R_{\\mu\\nu\\rho\\sigma} R^{\\mu\\nu\\rho\\sigma}$, $\\phi\nR_{\\mu\\nu\\rho\\sigma} \\tilde R^{\\mu\\nu\\rho\\sigma}$, because they can emerge if\nthere exist particles heavier than it. We derive these scalar couplings to the\nquadratic curvature by integrating out heavy particles in a systematic manner.\nSuch couplings are of phenomenological interest since some of them induce the\nscalar decay into the graviton pair. We point out that the decay of a scalar\nfield can produce a substantial amount of the stochastic cosmic graviton\nbackground at high frequency since the suppression scale of these operators is\ngiven by the mass of heavy particles not by the Planck scale. The resultant\ngraviton spectrum is computed in some concrete models.", "category": "hep-ph" }, { "text": "Search for Physics Beyond the Standard Model: We survey some recent ideas and progress in looking for particle physics\nbeyond the Standard Model, connected by the theme of Supersymmetry (SUSY). We\nreview the success of SUSY-GUT models, the expected experimental signatures and\npresent limits on SUSY partner particles, and Higgs phenomenology in the\nminimal SUSY model.", "category": "hep-ph" }, { "text": "Probing the QCD Equation of State: We propose a novel quasiparticle interpretation of the equation of state of\ndeconfined QCD at finite temperature. Using appropriate thermal masses, we\nintroduce a phenomenological parametrisation of the onset of confinement in the\nvicinity of the phase transition. Lattice results of bulk thermodynamic\nquantities are well reproduced, the extension to small quark chemical potential\nis also successful. We then apply the model to dilepton production and charm\nsuppression in ultrarelativistic heavy-ion collisions.", "category": "hep-ph" }, { "text": "The High Density Parton Dynamics from Eikonal and Dipole Pictures: In this contribution we discuss distinct approaches for the high density QCD\n(hdQCD) and the demonstration of the equivalence between the AGL approach and\nthe K approach is presented. Our conclusion is that the AGL equation is a good\ncandidate for an unitarized evolution equation at high densities in the DLA\nlimit.", "category": "hep-ph" }, { "text": "Approximate degeneracy of heavy-light mesons with the same $L$: Careful observation of the experimental spectra of heavy-light mesons tells\nus that heavy-light mesons with the same angular momentum $L$ are almost\ndegenerate. The estimate is given how much this degeneracy is broken in our\nrelativistic potential model, and it is analytically shown that expectation\nvalues of a commutator between the lowest order Hamiltonian and ${\\vec L}^{~2}$\nare of the order of $1/m_Q$ with a heavy quark mass $m_Q$. It turns out that\nnonrelativistic approximation of heavy quark system has a rotational symmetry\nand hence degeneracy among states with the same $L$. This feature can be tested\nby measuring higher orbitally and radially excited heavy-light meson spectra\nfor $D/D_s/B/B_s$ in LHCb and forthcoming BelleII.", "category": "hep-ph" }, { "text": "Atlas of solar hidden photon emission: Hidden photons, gauge bosons of a U(1) symmetry of a hidden sector, can\nconstitute the dark matter of the universe and a smoking gun for large volume\ncompactifications of string theory. In the sub-eV mass range, a possible\ndiscovery experiment consists on searching the copious flux of these particles\nemitted from the Sun in a helioscope setup \\`a la Sikivie. In this paper, we\ncompute the flux of transversely polarised HPs from the Sun, a necessary\ningredient for interpreting such experiments. We provide a detailed exposition\nof photon-HP oscillations in inhomogenous media, with special focus on\nresonance oscillations, which play a leading role in many cases. The region of\nthe Sun emitting HPs resonantly is a thin spherical shell for which we justify\nan averaged-emission formula and which implies a distinctive morphology of the\nangular distribution of HPs on Earth in many cases. Low mass HPs with energies\nin the visible and IR have resonances very close to the photosphere where the\nsolar plasma is not fully ionised and requires building a detailed model of\nsolar refraction and absorption. We present results for a broad range of HP\nmasses (from 0-1 keV) and energies (from the IR to the X-ray range), the most\ncomplete atlas of solar HP emission to date.", "category": "hep-ph" }, { "text": "Twist expansion of the nucleon structure functions, F2 and FL, in the\n DGLAP improved saturation model: Higher twist effects in the deeply inelastic scattering are studied. We start\nwith a short review of the theoretical results on higher twists in QCD. Within\nthe saturation model we perform a twist analysis of the nucleon structure\nfunctions FT and FL at small value of the Bjorken variable x. The parameters of\nthe model are fitted to the HERA F2 data, and we derive a prediction for the\nlongitudinal structure function FL. We conclude that for FL the higher twist\ncorrections are sizable whereas for F2 = FT + FL there is a nearly complete\ncancellation of twist-4 corrections in FT and FL. We discuss a few consequences\nfor future LHC measurements.", "category": "hep-ph" }, { "text": "Hadron production in non linear relativistic mean field models: By using a parametrization of the non-linear Walecka model which takes into\naccount the binding energy of different hyperons, we present a study of\nparticle production yields measured in central Au-Au collision at RHIC. Two\nsets of different hyperon-meson coupling constants are employed in obtaining\nthe hadron production and chemical freeze-out parameters. These quantities show\na weak dependence on the used hyperon-meson couplings. Results are in good\noverall accordance with experimental data. We have found that the repulsion\namong the baryons is quite small and, through a preliminary analysis of the\neffective mesonic masses, we suggest a way to improve the fittings.", "category": "hep-ph" }, { "text": "The ttbar threshold at a muon collider: The beam energy spread is a major issue in future attempts to study the\n$t\\overline{t}$ threshold at $e^+e^-$ colliders. Muon colliders are expected to\nnaturally have narrow band beams making them an ideal place to study the\nexcitation curve. We present the parameter determinations that are possible\nfrom measuring the total cross section near threshold at a $\\mu ^+\\mu ^-$\ncollider.", "category": "hep-ph" }, { "text": "Hadron Resonance Gas Model with Induced Surface Tension: Here we present a physically transparent generalization of the multicomponent\nVan der Waals equation of state in the grand canonical ensemble. For the\none-component case the third and fourth virial coefficients are calculated\nanalytically. It is shown that an adjustment of a single model parameter allows\nus to reproduce the third and fourth virial coefficients of the gas of hard\nspheres with small deviations from their exact values. A thorough comparison of\nthe compressibility factor and speed of sound of the developed model with the\none and two component Carnahan-Starling equation of state is made. It is shown\nthat the model with the induced surface tension is able to reproduce the\nresults of the Carnahan-Starling equation of state up to the packing fractions\n0.2-0.22 at which the usual Van der Waals equation of state is inapplicable. At\nhigher packing fractions the developed equation of state is softer than the gas\nof hard spheres and, hence, it breaks causality in the domain where the\nhadronic description is expected to be inapplicable. Using this equation of\nstate we develop an entirely new hadron resonance gas model and apply it to a\ndescription of the hadron yield ratios measured at AGS, SPS, RHIC and ALICE\nenergies of nuclear collisions. The achieved quality of the fit per degree of\nfreedom is about 1.08. We confirm that the strangeness enhancement factor has a\npeak at low AGS energies, while at and above the highest SPS energy of\ncollisions the chemical equilibrium of strangeness is observed. We argue that\nthe chemical equilibrium of strangeness, i.e. $\\gamma_s \\simeq 1$, observed\nabove the center of mass collision energy 4.3 GeV may be related to the\nhadronization of quark gluon bags which have the Hagedorn mass spectrum, and,\nhence, it may be a new signal for the onset of deconfinement.", "category": "hep-ph" }, { "text": "Nongauge antisymmetric-tensor bosons mediating interactions in the\n hidden sector: In a recent work, we have constructed a model of hidden sector of the\nUniverse, consisting of sterile spin-1/2 Dirac fermions (\"sterinos\"), sterile\nspin-0 bosons (\"sterons\") conjectured to get spontaneously nonzero vacuum\nexpectation value, and also of conventional photons assumed to participate both\nin the hidden and Standard-Model sectors (after the electroweak symmetry is\nspontaneously broken by the Standard-Model Higgs mechanism). This provides a\n\"photonic portal\" to the hidden sector as an alternative to the popular \"Higgs\nportal\". Moreover, we have proposed to stop the proliferation of new kinds of\ngauge bosons as sterile mediators of nongravitational interactions in the\nhidden sector, introducing instead nongauge mediating bosons described by an\nantisymmetric-tensor field (of dimension one), whose sources are given not only\nby sterino-antisterino pairs, but also by steron-photon pairs. Then,\nconventional photons display, beside the familiar gauge coupling to the\nStandard-Model electric current, a new nongauge weak coupling of sterile\nantisymmetric-tensor bosons to steron-photon pairs, where photons are described\nby the gauge-invariant electromagnetic field F_{\\mu \\nu}. The new mediators are\nunstable, decaying, for instance, into electron-positron pairs. When\ninteracting in pairs, they can annihilate simply into two photons. The\ncorresponding cross-section is calculated.", "category": "hep-ph" }, { "text": "Probing neutrino masses with future galaxy redshift surveys: We perform a new study of future sensitivities of galaxy redshift surveys to\nthe free-streaming effect caused by neutrino masses, adding the information on\ncosmological parameters from measurements of primary anisotropies of the cosmic\nmicrowave background (CMB). Our reference cosmological scenario has nine\nparameters and three different neutrino masses, with a hierarchy imposed by\noscillation experiments. Within the present decade, the combination of the\nSloan Digital Sky Survey (SDSS) and CMB data from the PLANCK experiment will\nhave a 2-sigma detection threshold on the total neutrino mass close to 0.2 eV.\nThis estimate is robust against the inclusion of extra free parameters in the\nreference cosmological model. On a longer term, the next generation of\nexperiments may reach values of order sum m_nu = 0.1 eV at 2-sigma, or better\nif a galaxy redshift survey significantly larger than SDSS is completed. We\nalso discuss how the small changes on the free-streaming scales in the normal\nand inverted hierarchy schemes are translated into the expected errors from\nfuture cosmological data.", "category": "hep-ph" }, { "text": "Searching for a New Source(s) of T-Violation in Spin Dependent Total\n Cross Section Measurements: We first re-prove with a more complete method that the the minimum standard\nmodel, with the inclusion of the CKM-matrix, requires the T-odd/P-odd total\ncross section of two spin-1/2 particles to vanish in all orders\\cite{gxu}. Then\nwe study the contribution to T-odd/P-odd total scattering cross sections from\nvarious channels within the Higgs sector, and optimize conditions for possible\nexperimental measurements of these effects. These studies show that such\ncontributions can appear at tree level, and that the spin dependent cross\nsection asymmetry is measurable if the lightest Higgs paarticle is not too\nmassive, {\\it e.g.} $m_H \\sim 200 GeV$, and if suitable reaction channels and\nbeam energies and luminosities are chosen.", "category": "hep-ph" }, { "text": "Studies of the ambient light of deep Baikal waters with Baikal-GVD: The Baikal-GVD neutrino detector is a deep-underwater neutrino telescope\nunder construction and recently after the winter 2023 deployment it consists of\n3456 optical modules attached on 96 vertical strings. This 3-dimensional array\nof photo-sensors allows to observe ambient light in the vicinity of the\nBaikal-GVD telescope that is associated mostly with water luminescence. Results\non time and space variations of the luminescent activity are reviewed based on\ndata collected in 2018-2022.", "category": "hep-ph" }, { "text": "Right-handed current contributions in B -> K pi decays: We reexamine the right-handed current effects in $b \\to s$ transitions in\nnonmanifest left-right models. Using the effective Hamiltonian approach\nincluding all possible low-energy operators, we obtain especially the B \\to K\n\\pi decay amplitudes including annihilation contributions, and investigate the\nright-handed current contributions to CP asymmetries in $B \\to K \\pi$ decays.\nTaking into account the constraints from global analysis of muon decay\nmeasurements, |V_{ub}| measurements in inclusive and exclusive B decays, and\n$B_s^0-\\bar{B_s^0}$ mixing measurements, we find the allowed regions of new\nphysics parameters satisfying the current experimental data.", "category": "hep-ph" }, { "text": "Detecting Tau Neutrino Oscillations at PeV Energies: It is suggested that a large deep underocean (or ice) neutrino detector,\ngiven the presence of significant numbers of neutrinos in the PeV energy range\nas predicted by various models of Active Galactic Nuclei, can make unique\nmeasurements of the properties of neutrinos. It will be possible to observe the\nexistence of the tau neutrino, measure its mixing with other flavors, in fact\ntest the mixing pattern for all three flavors based upon the mixing parameters\nsuggested by the atmospheric and solar neutrino data, and measure the tau\nneutrino cross section. The key signature is the charged current tau neutrino\ninteraction, which produces a double cascade, one at either end of a lightly\nradiating track. At a few PeV these cascades would be separated by roughly 100\nm, and thus be easily resolvable in next generation DUMAND-like detectors.\nFirst examples might be found in detectors presently under construction. Future\napplications are precise neutrino astronomy and earth tomography. This paper is\nan expanded version of hep-ph/9405296, for publication.", "category": "hep-ph" }, { "text": "Gravitational Instabilities of the Cosmic Neutrino Background with\n Non-zero Lepton Number: We argue that a cosmic neutrino background that carries non-zero lepton\ncharge develops gravitational instabilities. Fundamentally, these instabilities\nare related to the mixed gravity-lepton number anomaly. We have explicitly\ncomputed the gravitational Chern-Simons term which is generated\nquantum-mechanically in the effective action in the presence of a lepton number\nasymmetric neutrino background. The induced Chern-Simons term has a twofold\neffect: (i) gravitational waves propagating in such a neutrino background\nexhibit birefringent behaviour leading to an enhancement/suppression of the\ngravitational wave amplitudes depending on the polarisation, where the\nmagnitude of this effect is related to the size of the lepton asymmetry; (ii)\nNegative energy graviton modes are induced in the high frequency regime, which\nleads to very fast vacuum decay producing, e.g., positive energy photons and\nnegative energy gravitons. From the constraint on the present radiation energy\ndensity, we obtain an interesting bound on the lepton asymmetry of the\nuniverse.", "category": "hep-ph" }, { "text": "$\u03b2$-function for topologically massive gluons: We calculate the quantum corrections to the two-point function of four\ndimensional topologically massive non-Abelian vector fields at one loop order\nfor $SU(N)$ gauge theory in Feynman-'t Hooft gauge. We calculate the beta\nfunction of the gauge coupling constant and find that the theory becomes\nasymptotically free faster than pure $SU(N)$ gauge theory.", "category": "hep-ph" }, { "text": "Electroweak Physics: We review the prospects for studies in electroweak physics at the LHC.", "category": "hep-ph" }, { "text": "Status of Constraints on Supersymmetry: A short summary of constraints on the parameter space of supersymmetric\nmodels is given. Experimental limits from high energy colliders, electroweak\nprecision data, flavor and Higgs physics, and cosmology are considered. The\nmain focus is on the MSSM with conserved R- and CP-parity and minimal flavor\nviolation, but more general scenarios and extended models will also be\ndiscussed briefly.", "category": "hep-ph" }, { "text": "A novel left-right symmetric model: A novel gauge model which has a spontaneously broken parity symmetry is\nconstructed. The model has only 2 parameters beyond those of the standard\nmodel. Some of the unusual implications of the model are discussed.", "category": "hep-ph" }, { "text": "Hard inclusive production and a violation of the factorization theorem: A new mechanism for hard inclusive production, which leads to a violation of\nthe factorization theorem, is suggested. The mechanism is illustrated by a\ndetailed discussion of Higgs meson production in high energy deutron-deutron\nscattering. Numerical estimates for the effect are given for high energy hadron\n(nucleus) scattering.", "category": "hep-ph" }, { "text": "Exact formulae for Higgs production through e gamma --> e H in the\n non-linear R_\u03begauge: We study the production of the SM Higgs boson (H^0) at future e gamma\ncolliders, through the reaction e gamma --> e H^0. The amplitude is evaluated\nusing the non-linear R_\\xi gauge, which greatly simplifies the calculation.\nComplete analytical expressions for the amplitudes are presented, which include\nthe contributions from 1-loop triangles \"gamma gamma^* H^0\" and \"gamma Z^* H^0\"\nas well as the W- and Z-boxes with their related $eeH^0$ triangle graphs. The\nresulting cross section for this mechanism indicates that it could be used to\ndetect the Higgs signal and to test its properties.", "category": "hep-ph" }, { "text": "Slepton pair production at the LHC in NLO+NLL with resummation-improved\n parton densities: Novel PDFs taking into account resummation-improved matrix elements, albeit\nonly in the fit of a reduced data set, allow for consistent NLO+NLL\ncalculations of slepton pair production at the LHC. We apply a factorisation\nmethod to this process that minimises the effect of the data set reduction,\navoids the problem of outlier replicas in the NNPDF method for PDF\nuncertainties and preserves the reduction of the scale uncertainty. For Run II\nof the LHC, left-handed selectron/smuon, right-handed and maximally mixed stau\nproduction, we confirm that the consistent use of threshold-improved PDFs\npartially compensates the resummation contributions in the matrix elements.\nTogether with the reduction of the scale uncertainty at NLO+NLL, the described\nmethod further increases the reliability of slepton pair production cross\nsections at the LHC.", "category": "hep-ph" }, { "text": "Gauge Coupling Unification in Gauge-Higgs Grand Unification: We discuss renormalization group equations for gauge coupling constants in\ngauge-Higgs grand unification on five-dimensional Randall-Sundrum warped space.\nWe show that all the four-dimensional Standard Model gauge coupling constants\nare asymptotically free and are effectively unified in $SO(11)$ gauge-Higgs\ngrand unified theories on 5D Randall-Sundrum warped space.", "category": "hep-ph" }, { "text": "\u03bc-\u03c4Symmetry and Maximal CP Violation: We argue the possibility that a real part of a flavor neutrino mass matrix\nonly respects a mu-tau symmetry. This possibility is shown to be extended to\nmore general case with a phase parameter \\theta, where the mu-tau symmetric\npart has a phase of \\theta/2. This texture shows maximal CP violation and no\nMajorana CP violation.", "category": "hep-ph" }, { "text": "Low-Scale Leptogenesis and the Domain Wall Problem in Models with\n Discrete Flavor Symmetries: We propose a new mechanism for leptogenesis, which is naturally realized in\nsome models with a flavor symmetry based on the discrete group A_4, where the\nsymmetry breaking parameter also controls the Majorana masses for the heavy\nright handed (RH) neutrinos. During the early universe, for T>TeV, part of the\nsymmetry is restored, due to finite temperature contributions, and the RH\nneutrinos remain massless and can be produced in thermal equilibrium even at\ntemperatures well below the most conservative gravitino bounds. Below this\ntemperature the phase transition occurs and they become massive, decaying out\nof equilibrium and producing the necessary lepton asymmetry. Unless the\nsymmetry is broken explicitly by Planck-suppressed terms, the domain walls\ngenerated by the symmetry breaking survive till the quark-hadron phase\ntransition, where they disappear due to a small energy splitting between\ndifferent vacua caused by the QCD anomaly.", "category": "hep-ph" }, { "text": "Overview of Neutrino Mixing Models and Ways to Differentiate among Them: An overview of neutrino-mixing models is presented with emphasis on the types\nof horizontal flavor and vertical family symmetries that have been invoked.\nDistributions for the mixing angles of many models are displayed. Ways to\ndifferentiate among the models and to narrow the list of viable models are\ndiscussed.", "category": "hep-ph" }, { "text": "Hadronic Final States in DIS at NNLO QCD with Parton Showers: We present a parton-shower matched NNLO QCD calculation for hadronic final\nstate production in Deep Inelastic Scattering. The computation is based on the\nUNLOPS method and is implemented in the publicly available event generation\nframework SHERPA. Results are compared to measurements performed by the H1\ncollaboration.", "category": "hep-ph" }, { "text": "Searches for Decays of New Particles in the DUNE Multi-Purpose Near\n Detector: One proposed component of the upcoming Deep Underground Neutrino Experiment\n(DUNE) near detector complex is a multi-purpose, magnetized, gaseous argon time\nprojection chamber: the Multi-Purpose Detector (MPD). We explore the\nnew-physics potential of the MPD, focusing on scenarios in which the MPD is\nsignificantly more sensitive to new physics than a liquid argon detector,\nspecifically searches for semi-long-lived particles that are produced in/near\nthe beam target and decay in the MPD. The specific physics possibilities\nstudied are searches for dark vector bosons mixing kinetically with the\nStandard Model hypercharge group, leptophilic vector bosons, dark scalars\nmixing with the Standard Model Higgs boson, and heavy neutral leptons that mix\nwith the Standard Model neutrinos. We demonstrate that the MPD can extend\nexisting bounds in most of these scenarios. We illustrate how the ability of\nthe MPD to measure the momentum and charge of the final state particles leads\nto these bounds.", "category": "hep-ph" }, { "text": "Enhanced Higgs Mass in a Gaugino Mediation Model without the Polonyi\n Problem: We consider a SUSY breaking scenario without the Polonyi problem. To solve\nthe problem, the enhanced couplings of the Polonyi field to an inflaton, gauge\nkinetic functions and itself are assumed. As a result, a gaugino mediated SUSY\nbreaking occurs. In this scenario, the Higgs boson mass becomes consistent with\nthe recently observed value of the Higgs-like boson (i.e., m_h ~= 125 GeV) for\nthe gluino mass about 4TeV, which is, however, out of the reach of the LHC\nexperiment. We show that the trilinear coupling of the scalar top is\nautomatically enhanced by the presence of the extra matters. With such extra\nmatters, the Higgs mass as large as 125 GeV can be realized with the gluino\nmass of 1-2 TeV which is within the reach of the LHC experiment. In our\nscenario, the gravitino is the lightest SUSY particle and the candidate for\ndark matter, and the Wino, Bino, and sleptons are in a range from 200 GeV to\n700 GeV.", "category": "hep-ph" }, { "text": "Mass Spectra of $D$, $D_s$ Mesons using Dirac formalism with martin-like\n confinement potential: We have calculated mass spectra of $D$, $D_s$ mesons using Dirac formalism\nwith Martin-like potential in Potential model.", "category": "hep-ph" }, { "text": "Matter Effects on Long Baseline Neutrino Oscillation Experiments: We calculate matter effects on neutrino oscillations relevant for long\nbaseline neutrino oscillation experiments. In particular, we compare the\nresults obtained with simplifying approximations for the density profile in the\nEarth versus results obtained with actual density profiles. We study the\ndependence of the oscillation signals on both $E/\\Delta m^2_{atm.}$ and on the\nangles in the leptonic mixing matrix. The results show quantitatively how\nmatter effects can cause significant changes in the oscillation signals,\nrelative to vacuum oscillations and can be useful in amplifying these signals\nand helping one to obtain measurements of mixing parameters and the magnitude\nand sign of $\\Delta m^2$.", "category": "hep-ph" }, { "text": "On the Nature of X(4260): We study the property of $X(4260)$ resonance by re-analyzing all experimental\ndata available, especially the $e^+e^- \\rightarrow\nJ/\\psi\\,\\pi^+\\pi^-,\\,\\,\\,\\omega\\chi_{c0}$ cross section data. The final state\ninteractions of the $\\pi\\pi$, $K\\bar K$ couple channel system are also taken\ninto account. A sizable coupling between the $X(4260)$ and $\\omega\\chi_{c0}$ is\nfound. The inclusion of the $\\omega\\chi_{c0}$ data indicates a small value of\n$\\Gamma_{e^+e^-}=23.30\\pm 3.55$eV.", "category": "hep-ph" }, { "text": "Muon conversion to electron in nuclei within the BLMSSM: In a supersymmetric extension of the standard model with local gauged baryon\nand lepton numbers (BLMSSM), there are new sources for lepton flavor violation,\nbecause the right-handed neutrinos, new gauginos and Higgs are introduced. We\ninvestigate muon conversion to electron in nuclei within the BLMSSM in detail.\nThe numerical results indicate that the $\\mu \\rightarrow e $ conversion rates\nin nuclei within the BLMSSM can reach the experimental upper bound, which may\nbe detected in the future experiments.", "category": "hep-ph" }, { "text": "Next-to-leading order QCD corrections to the top quark decay via\n model-independent FCNC couplings: D0 and CDF collaborations at the Fermilab Tevatron have searched for\nnon-standard-model single top-quark production and set upper limits on the\nanomalous top quark flavor-changing neutral current (FCNC) couplings\n$\\kappa^g_{tc}/\\Lambda$ and $\\kappa^g_{tu}/\\Lambda$ using the measurement of\ntotal cross section calculated at the next-to-leading order (NLO) in QCD. In\nthis Letter, we report on the effect of anomalous FCNC couplings to various\ndecay branching ratios of the top quark, calculated at the NLO. This result is\nnot only mandatory for a consistent treatment of both the top quark production\nand decay via FCNC couplings by D0 and CDF at the Tevatron but is also\nimportant for the study of ATLAS and CMS sensitivity to these anomalous\ncouplings at the CERN LHC. We find that the NLO corrections to the partial\ndecay widths of the three decay channels $ t\\to q + g$, $ t\\to q + \\gamma$ and\n$ t\\to q + Z$ are at the order of 10% in magnitude and modify their branching\nratios by about 20%, 0.4% and 2%, respectively, as compared to their leading\norder predictions.", "category": "hep-ph" }, { "text": "Curvature and thermal corrections in tree-level CPT-Violating\n Leptogenesis: In a model for leptogenesis based on spontaneous breaking of Lorentz and CPT\nsymmetry [1-3], we examine the consistency of using the approximation of\nplane-wave solutions for a free spin-(1/2) Dirac (or Majorana) fermion field\npropagating in a Friedmann-Lemaitre-Robertson-Walker space time augmented with\na cosmic time-dependent (or, equivalently, a temperature-dependent) Kalb-Ramond\n(KR) background. For the range of parameters relevant for leptogenesis, our\nanalysis fully justifies the use of plane-wave solutions in our study of\nleptogenesis with Boltzmann equations; any corrections induced by\nspace-time-curvature are negligible. We also elaborate further on how the\nlepton asymmetry is communicated to the Baryon sector. We demonstrate that the\nKR background (KRB) does not contribute to the anomaly equations that determine\nthe baryon asymmetry a) through an explicit evaluation of a triangle Feynman\ngraph and b) indirectly, on topological grounds, by identifying the KRB as\ntorsion (in the effective string-inspired low energy gravitational field\ntheory).", "category": "hep-ph" }, { "text": "Empirical regularities in the $x$--dependence of nuclear J/Psi\n suppression: The measured ratios $R(x,A_1/A_2)$ for $J/\\Psi$, $\\Psi'$ and $\\mu^+\\mu^-$\nproduction on two different targets $A_1, A_2$ as a function of the fractional\nmomentum $x$ of the final state are well fit with a very simple functional form\nhaving three adjustable parameters. An empirical relation is found between the\nthree parameters of the fit. The deduced $J/\\Psi$ absorption cross sections\n$\\sigma_{abs}$ cluster around two values of which only $\\sigma_{abs} = 5.8 \\pm\n0.2$ mb seems acceptable.", "category": "hep-ph" }, { "text": "Chromomagnetic dipole moment of the top quark in the Bestest Little\n Higgs model: We calculate the chromomagnetic dipole moment of the top quark,\n$\\hat{\\mu}_t$, in the context of the Bestest Little Higgs model. This extension\nof the Standard Model aims to solve the hierarchy problem without fine tuning,\nby introducing one-loop corrections to the Higgs boson mass through heavy top\nquark partners and heavy gauge bosons. We found that the largest resulting\nvalue for the chromomagnetic is $\\hat{\\mu}_t\\sim 10^{-5}$ and the lowest is\naround $10^{-6}$, mainly due to the Higgs boson of the Standard Model, which\ncouples to both the top quark of the Standard Model and its heavy partners.\nAlso, we present a wide variety of new Feynman rules involved in our\ncalculation.", "category": "hep-ph" }, { "text": "Contribution of the elastic radiative tail to the deep inelastic muon\n scattering on heavy targets: Improvement of the radiative correction scheme for the deep inelastic\nscattering on the heavy targets is discussed. Arguments that the contribution\nof the radiative tail from the elastic peak should be calculated without use of\nthe Born approximation in the case of the heavy target scattering are\npresented. The semianalytical approach based on the classical solution of the\nold bremsstrahlung problem is shortly described. The numerical results for the\nnew correction factor are presented for the scattering on tin and lead.", "category": "hep-ph" }, { "text": "On-shell renormalisation constants including two different nonzero\n masses: We present results for the effect of a second massive quark in the relation\nbetween the pole and the minimal subtracted quark mass at the three loop level.\nWe also consider the analogous effect for the wave function renormalisation\nconstant. Some technical details of the calculation are given. Our result is\nphenomenologically relevant for the bottom quark including virtual charm\neffects.", "category": "hep-ph" }, { "text": "Color path-integral Monte Carlo simulations of quark-gluon plasma: Thermodynamic properties of a strongly coupled quark-gluon plasma (QGP) of\nconstituent quasiparticles are studied by a color path-integral Monte Carlo\nsimulations (CPIMC). For our simulations we have presented QGP partition\nfunction in the form of color path integral with new relativistic measure\ninstead of Gaussian one used in Feynman and Wiener path integrals. For\nintegration over color variable we have also developed procedure of sampling\ncolor variables according to the group SU(3) Haar measure. It is shown that\nthis method is able to reproduce the available quantum lattice chromodynamics\n(QCD) data.", "category": "hep-ph" }, { "text": "Primordial Lepton Oscillations and Baryogenesis: The baryon asymmetry of the Universe should have been produced after the\ninflation era. We consider the possibility that the asymmetry is generated by\nthe flavor oscillations in the reheating process after inflation, so that the\nbaryon asymmetry is realized already at the beginning of the radiation\ndominated era. In the seesaw model, we show that the propagators of the\nleft-handed leptons generically have flavor mixings in the thermal background,\nthat can generate flavor-dependent lepton asymmetry through the $CP$ violation\nin the oscillation phenomena. The flavor dependent rates for the wash-out\nprocess can leave the net asymmetry today.", "category": "hep-ph" }, { "text": "External-leg corrections as an origin of large logarithms: Obtaining precise theoretical predictions for both production and decay\nprocesses of heavy new particles is of great importance to constrain the\nallowed parameter spaces of Beyond-the-Standard-Model (BSM) theories, and to\nproperly assess the sensitivity for discoveries and for discriminating between\ndifferent possible BSM scenarios. In this context, it is well known that large\nlogarithmic corrections can appear in the presence of widely separated mass\nscales. We point out the existence of a new type of possible large,\nSudakov-like, logarithms in external-leg corrections of heavy scalars. To the\ndifference of usual Sudakov logarithms, these can furthermore potentially be\nenhanced by large trilinear couplings. Such large logarithms are associated\nwith infrared singularities and we review several techniques to address these\nat one loop. In addition to this discussion, we also present the derivation of\nthe two-loop corrections containing this type of large logarithms, pointing out\nin this context the importance of adopting an on-shell renormalisation scheme.\nFinally, we illustrate our calculations and examine the possible magnitude of\nthese corrections for a simple scalar toy model as well as for decay processes\ninvolving heavy stop quarks in the Minimal Supersymmetric Standard Model and a\nheavy Higgs boson in the Next-to-Two-Higgs-Doublet Model.", "category": "hep-ph" }, { "text": "The 2HD+a model for a combined explanation of the possible excesses in\n the CDF $\\mathbf{M_W}$ measurement and $\\mathbf{(g-2)_\u03bc}$ with Dark Matter: The new measurement of the $W$ boson mass performed by the CDF experiment at\nthe Tevatron shows a significant deviation not only with the expectation in the\nStandard Model but also with other precision measurements performed at LEP, the\nTevatron and the LHC. We nevertheless take this new measurement at face value\nand interpret it as an effect of new physics. We particularly try to link it\nwith other possible anomalies such as the recent muon $g-2$ and consider a\nscenario that addresses some shortcomings of the Standard Model. We show that a\nmodel with two doublets and a light pseudoscalar Higgs fields, supplemented by\na stable isosinglet fermion, can simultaneously explain the possible $M_W$ and\n$(g-2)_\\mu$ anomalies and accounts for the weakly interacting massive particle\nthat could be responsible of the dark matter in the universe.", "category": "hep-ph" }, { "text": "Weak decays of doubly heavy baryons: decays to system of $\u03c0$ mesons: In the presented article we consider exclusive weak decays of doubly heavy\nbaryons with spin $J=1/2$ with production of leptonic pair or a set of light\nmesons. Using QCD factorization theorem and spectral functions approach we\nobtain theoretical predictions for the partial probabilities of these decays\nand distributions over various kinematic variables. According to the obtaining\nresults partial probabilities of some of researched decays are large enough to\nbe observed experimentally.", "category": "hep-ph" }, { "text": "Light-cone distribution amplitudes of light mesons with QED effects: We discuss the generalization of the leading-twist light-cone distribution\namplitude for light mesons including QED effects. This generalization was\nintroduced to describe virtual collinear photon exchanges above the\nstrong-interaction scale $\\Lambda_{\\rm QCD}$ in the factorization of QED\neffects in non-leptonic $B$-meson decays. In this paper we study the\nrenormalization group evolution of this non-perturbative function. For charged\nmesons, in particular, this exhibits qualitative differences with respect to\nthe well-known scale evolution in QCD only, especially regarding the\nendpoint-behaviour. We analytically solve the evolution equation to first order\nin the electromagnetic coupling $\\alpha_{\\rm em}$, which resums large\nlogarithms in QCD on top of a fixed-order expansion in $\\alpha_{\\rm em}$. We\nfurther provide numerical estimates for QED corrections to Gegenbauer\ncoefficients as well as inverse moments relevant to (QED-generalized)\nfactorization theorems for hard exclusive processes.", "category": "hep-ph" }, { "text": "Towards a determination of the tau lepton dipole moments: The tau anomalous magnetic moment (a_tau) and electric dipole moment (d_tau)\nhave not yet been observed. The present bounds on their values are of order\n10^-2 and 10^-17 e*cm, respectively. We propose to measure a_tau with a\nprecision of O(10^-3) or better and improve the existing limits on d_tau using\nprecise tau- -> l- nu_tau \\bar{nu}_l gamma (l=e or mu) data from\nhigh-luminosity B factories. A detailed feasibility study of this method is\nunderway.", "category": "hep-ph" }, { "text": "Geometry of gauge links in operator definitions of transverse-momentum\n dependent PDFs: A comparative view: Different approaches to the problem of a gauge-invariant operator definition\nof transverse-momentum dependent parton densities (TMDs) are reviewed and\ncompared from the point of view of their compatibility with the operator\ndefinition of collinear (integrated) parton distribution functions. In\nparticular, geometry of the longitudinal and transverse gauge links (Wilson\nlines) both in unsubtracted quark TMDs and in the associate soft factors is\naddressed. A possible connection between different operator definitions is also\ndiscussed.", "category": "hep-ph" }, { "text": "Exclusive nonleptonic decays of B mesons: The energetic exclusive two-body nonleptonic decays of B mesons are\ninvestigated in the framework of the relativistic quark model within the\nfactorization approximation. The heavy quark expansion is used for the\ncalculation of form factors. The obtained results are in agrement with\navailable experimental data.", "category": "hep-ph" }, { "text": "Distinctive nuclear signatures of low-energy atmospheric neutrinos: New probes of neutrino mixing are needed to advance precision studies. One\npromising direction is via the detection of low-energy atmospheric neutrinos\n(below a few hundred MeV), to which a variety of near-term experiments will\nhave much-improved sensitivity. Here we focus on probing these neutrinos\nthrough distinctive nuclear signatures of exclusive neutrino-carbon\ninteractions -- those that lead to detectable nuclear-decay signals with low\nbackgrounds -- in both neutral-current and charged-current channels. The\nneutral-current signature is a line at 15.11 MeV and the charged-current\nsignatures are two- or three-fold coincidences with delayed decays. We\ncalculate the prospects for identifying such events in the Jiangmen Underground\nNeutrino Observatory (JUNO), a large-scale liquid-scintillator detector. A\nfive-year exposure would yield about 16 neutral-current events (all flavors)\nand about 16 charged-current events (mostly from $\\nu_e + \\bar{\\nu}_e$, with\nsome from $\\nu_\\mu + \\bar{\\nu}_\\mu$), and thus roughly 25\\% uncertainties on\neach of their rates. Our results show the potential of JUNO to make the first\nidentified measurement of sub-100 MeV atmospheric neutrinos. They also are a\nstep towards multi-detector studies of low-energy atmospheric neutrinos, with\nthe goal of identifying additional distinctive nuclear signatures for carbon\nand other targets.", "category": "hep-ph" }, { "text": "Charged Particle Fluctuations as a Signal of the Dynamics of Heavy Ion\n Processes: Comparing proposed quantities to analyze charged particle fluctuations in\nheavy ion experiments we find the dispersion of the charges in a central\nrapidity box as best suited. Various energies and different nuclear sizes were\nconsidered in an explicit Dual-Parton-Model calculation using the DPMJET code.\nA definite deviation from predictions of recently considered statistical models\nwas obtained. Hence the charged particle fluctuations should provide a clear\nsignal of the dynamics of heavy ion processes. They should allow to directly\nmeasure the degree of thermalization in a quantitative way.", "category": "hep-ph" }, { "text": "Particle-accelerator constraints on isotropic modifications of the speed\n of light: The absence of vacuum Cherenkov radiation for 104.5 GeV electrons and\npositrons at LEP combined with the observed stability of 300 GeV photons at the\nTevatron constrains deviations of the speed of light relative to the maximal\nattainable speed of electrons. Within the Standard-Model Extension (SME), the\nlimit $-5.8\\times10^{-12} \\leq \\tilde{\\kappa}_{\\rm tr}-{4/3}c_e^{00} \\leq\n1.2\\times10^{-11}$ is extracted, which sharpens previous bounds by more than 3\norders of magnitude. The potential for further refinements of this limit with\nterrestrial experiments and astrophysical observations is discussed.", "category": "hep-ph" }, { "text": "Beyond Low-Gribov theorem for high energy interactions of scalar and\n gauge particles: We obtain a generalization of the Low theorem for non-Abelian boson emission\nin collision of scalar and gauge vector particles and its extension to high\nenergy collisions for small transverse momenta of produced particles. We\ndemonstrate that in the case of particles with spin the direct extension the\nLow formula to high energy is in contradiction with the correct amplitude\nfactorization behavior. Consideration of different kinematical regions and use\nof methods of dual models allows us to separate contributions of intermediate\nexcited states and standard spin corrections in the Low formulae. We show that\nthe amplitude factorization occurs at high energy due to the contribution of\nthe intermediate states which is additional to the gluon production amplitude\nfor the scalar particle collision.", "category": "hep-ph" }, { "text": "Analytic representations of two-loop scattering amplitudes with internal\n masses: We highlight the latest developments in computing higher-order scattering\namplitudes with massive internal propagators. The contributing Feynman\nintegrals often lead to special classes of functions, for example, functions\nassociated with elliptic curves. With the presence of more scales in the\namplitudes, it becomes imperative to have a better understanding of the\ncontributing Feynman integrals and using current cutting-edge technologies to\ntackle the growth in analytic and algebraic complexities. In particular, we\nstart with discussing two-loop scattering amplitudes for top-quark pair\nproduction and conclude with motivating important steps towards obtaining\nnext-to-next-to leading-order corrections for five-point processes.", "category": "hep-ph" }, { "text": "Constraining Light Mediators via Detection of Coherent Elastic Solar\n Neutrino Nucleus Scattering: Dark matter (DM) direct detection experiments are entering the multiple-ton\nera and will be sensitive to the coherent elastic neutrino nucleus scattering\n(CE$\\nu$NS) of solar neutrinos, enabling the possibility to explore\ncontributions from new physics with light mediators at the low energy range. In\nthis paper we consider light mediator models (scalar, vector and axial vector)\nand the corresponding contributions to the solar neutrino CE$\\nu$NS process.\nMotivated by the current status of new generation of DM direct detection\nexperiments and the future plan, we study the sensitivity of light mediators in\nDM direct detection experiments of different nuclear targets and detector\ntechniques. The constraints from the latest $^8$B solar neutrino measurements\nof XENON-1T are also derived. Finally, We show that the solar neutrino\nCE$\\nu$NS process can provide stringent limitation on the $ L_{\\mu}-L_{\\tau} $\nmodel with the vector mediator mass below 100 MeV, covering the viable\nparameter space of the solution to the $ (g-2)_{\\mu}$ anomaly.", "category": "hep-ph" }, { "text": "QCD Analysis of the Polarized Deep-Inelastic World Data: The results of a recent next-to-leading order QCD analysis of the world data\non polarized deep inelastic scattering are reported. New parameterizations are\nderived for the quark and gluon distributions, accounting for the massive\nWilson coefficient for the charm quarks, and the value of $\\alpha_s(M_z^2)$ is\ndetermined with correlated errors. We obtain $\\alpha_s^{\\rm NLO}(M_Z^2)= 0.1132\n{array}{l} + 0.0056 -0.0095 {array}$. Limits on potential higher twist\ncontributions to the structure function $g_1(x,Q^2)$ are derived. We also\ncompare to the results obtained by other groups.", "category": "hep-ph" }, { "text": "HiggsSignals: Confronting arbitrary Higgs sectors with measurements at\n the Tevatron and the LHC: HiggsSignals is a Fortran90 computer code that allows to test the\ncompatibility of Higgs sector predictions against Higgs rates and masses\nmeasured at the LHC or the Tevatron. Arbitrary models with any number of Higgs\nbosons can be investigated using a model-independent input scheme based on\nHiggsBounds. The test is based on the calculation of a chi-squared measure from\nthe predictions and the measured Higgs rates and masses, with the ability of\nfully taking into account systematics and correlations for the signal rate\npredictions, luminosity and Higgs mass predictions. It features two\ncomplementary methods for the test. First, the peak-centered method, in which\neach observable is defined by a Higgs signal rate measured at a specific\nhypothetical Higgs mass, corresponding to a tentative Higgs signal. Second, the\nmass-centered method, where the test is evaluated by comparing the signal rate\nmeasurement to the theory prediction at the Higgs mass predicted by the model.\nThe program allows for the simultaneous use of both methods, which is useful in\ntesting models with multiple Higgs bosons. The code automatically combines the\nsignal rates of multiple Higgs bosons if their signals cannot be resolved by\nthe experimental analysis. We compare results obtained with HiggsSignals to\nofficial ATLAS and CMS results for various examples of Higgs property\ndeterminations and find very good agreement. A few examples of HiggsSignals\napplications are provided, going beyond the scenarios investigated by the LHC\ncollaborations. For models with more than one Higgs boson we recommend to use\nHiggsSignals and HiggsBounds in parallel to exploit the full constraining power\nof Higgs search exclusion limits and the measurements of the signal seen at\naround 125.5 GeV.", "category": "hep-ph" }, { "text": "Hybrid textures in minimal seesaw mass matrices: In the context of minimal seesaw framework, we study the implications of\nDirac and Majorana mass matrices in which two rigid properties coexist, namely,\nequalities among mass matrix elements and texture zeros. In the first part of\nthe study, we discuss general possibilities of the Dirac and Majorana mass\nmatrices for neutrinos with such hybrid structures. We then classify the mass\nmatrices into realistic textures which are compatible with global neutrino\noscillation data and unrealistic ones which do not comply with the data. Among\nthe large number of general possibilities, we find that only 6 patterns are\nconsistent with the observations at the level of the most minimal number of\nfree parameters. These solutions have only 2 adjustable parameters, so that all\nthe mixing angles can be described in terms of the two mass differences or pure\nnumbers. We analyze these textures in detail and discuss their impacts for\nfuture neutrino experiments and for leptogenesis.", "category": "hep-ph" }, { "text": "Boosted Dark Matter at the Deep Underground Neutrino Experiment: We investigate the detection prospects of a non-standard dark sector in the\ncontext of boosted dark matter. We consider a scenario where two stable\nparticles have a large mass difference and the heavier particle accounts for\nmost of dark matter in our current universe. The heavier candidate is assumed\nto have no interaction with the standard model particles at tree-level, hence\nevading existing constraints. Although subdominant, the lighter dark matter\nparticles are efficiently produced via pair-annihilation of the heavier ones in\nthe center of the Galaxy or the Sun. The large Lorentz boost enables detection\nof the non-minimal dark sector in large volume terrestrial experiments via\nexchange of a light dark photon with electrons or nuclei. Various experiments\ndesigned for neutrino physics and proton decay are examined in detail,\nincluding Super-K and Hyper-K. In this study, we focus on the sensitivity of\nthe far detector at the Deep Underground Neutrino Experiment for boosted dark\nmatter produced in the center of the Sun, and compare our findings with recent\nresults for boosted dark matter produced in the galactic center.", "category": "hep-ph" }, { "text": "Heavy-quark contributions to the ratio F_L/F_2 at low x: We study the heavy-quark contribution to the proton structure functions\nF_2^i(x,Q^2) and F_L^i(x,Q^2), with i=c,b, for small values of Bjorken's x\nvariable at next-to-lading order and provide compact formulas for their ratios\nR_i=F_L^i/F_2^i that are useful to extract F_2^i(x,Q^2) from measurements of\nthe doubly differential cross section of inclusive deep-inelastic scattering at\nDESY HERA. Our approach naturally explains why R_i is approximately independent\nof x and the details of the parton distributions in the small-x regime.", "category": "hep-ph" }, { "text": "QCD Effective Actions at High Temperature and the Quasiparticle Picture: Transport theory is an efficient approach to derive an effective theory for\nthe soft modes of QCD at high temperature. It is known that the leading order\noperators of this theory can be obtained from (semi-classical) kinetic\nequations of quasiparticles carrying classical or quantum color charges. Higher\norder operators can also be obtained. Discrepancy between these quasiparticle\nmodels starts for dimension 4 operators, which converge in the limit of high\ndimensional color representations. These quasiparticle models are reviewed and\ncompared.", "category": "hep-ph" }, { "text": "Probing Quintessence with Time Variation of Couplings: Many models of quintessence predict a time variation of the fundamental\nconstants as well as a composition-dependent gravity like long-range force\nmediated by the cosmon. We present bounds for the cosmon coupling to matter and\nradiation within a grand unified framework. The unification scale, the unified\ngauge coupling and the Fermi scale are allowed to vary independently. We find\nthat the variation of the weak scale compared to the nucleon mass is severely\nrestricted. The violation of the equivalence principle turns out to be\nsubstantially larger than in models where only the electromagnetic fine\nstructure constant varies with time. We also show that in contrast to gravity\nthe local cosmon field in a condensed object does not decouple from the\ncosmological evolution. In consequence, the cosmon interaction constitutes a\npossible quantitative link between cosmological observations and several areas\nof high precision experiments concerning the local time or space variation of\ncouplings and tests of the equivalence principle.", "category": "hep-ph" }, { "text": "Isospin-conserving hadronic decay of the ${D_{s1}(2460)}$ into\n ${D_s\u03c0^+\u03c0^-}$: The internal structure of the charm-strange mesons $D_{s0}^*(2317)$ and\n$D_{s1}(2460)$ are subject of intensive studies. Their widths are small because\nthey decay dominantly through isospin-breaking hadronic channels\n$D_{s0}^*(2317)^+\\to D_s^+\\pi^0$ and $D_{s1}(2460)^+\\to D_s^{*+}\\pi^0$. The\n$D_{s1}(2460)$ can also decay into the hadronic final states $D_s^+\\pi\\pi$,\nconserving isospin. In that case there is, however, a strong suppression from\nphase space. We study the transition $D_{s1}(2460)^+\\to D_s^+\\pi^+\\pi^-$ in the\nscenario that the $D_{s1}(2460)$ is a $D^*K$ hadronic molecule. The $\\pi\\pi$\nfinal state interaction is taken into account through dispersion relations. We\nfind that the ratio of the partial widths of the $\\Gamma(D_{s1}(2460)^+\\to\nD_s^+\\pi^+\\pi^-)/\\Gamma(D_{s1}(2460)^+\\to D_s^{*+}\\pi^0)$ obtained in the\nmolecular picture is consistent with the existing experimental measurement.\nMore interestingly, we demonstrate that the $\\pi^+\\pi^-$ invariant mass\ndistribution shows a double bump structure, which can be used to disentangle\nthe hadronic molecular picture from the compact state picture for the\n$D_{s1}(2460)^+$. Predictions on the $B_{s1}^0\\to B_s^0\\pi^+\\pi^-$ are also\nmade.", "category": "hep-ph" }, { "text": "A comparison between direct and indirect dark matter search: We carry out a comparison between different kinds of experiments for the\ndetection of neutralino dark matter. In particular, we compare the theoretical\npredictions for the direct detection of these particles, through their elastic\nscattering on target nuclei through nuclear recoils, with those for their\nindirect detection through the gamma rays produced by their annihilation in the\ngalactic center. For the comparison we pay special attention to points which\nwill be testable by very sensitive experiments, such as e.g. EDELWEISS II and\nGENIUS for direct detection, and GLAST for indirect detection. We perform the\nanalysis in the framework of a general SUGRA theory, allowing the presence of\nnon-universal soft scalar and gaugino masses in the parameter space. As a\nconclusion, we find that indirect detection experiments will be able to test\nlarger regions of the parameter space than direct detection ones.", "category": "hep-ph" }, { "text": "Deconfinement and Chiral Symmetry Restoration in a Strong Magnetic\n Background: We perform a model study of deconfinement and chiral symmetry restoration in\na strong magnetic background. We use a Nambu-Jona Lasinio model with the\nPolyakov loop, taking into account a possible dependence of the coupling on the\nPolyakov loop expectation value, as suggested by the recent literature. Our\nmain result is that, within this model, the deconfinement and chiral crossovers\nof QCD in strong magnetic field are entangled even at the largest value of $eB$\nconsidered here, namely $eB=30 m_\\pi^2$ (that is, $B \\approx 6\\times 10^{15}$\nTesla). The amount of split that we measure is, at this value of $eB$, of the\norder of 2%. We also study briefly the role of the 8-quark term on the\nentanglement of the two crossovers. We then compare the phase diagram of this\nmodel with previous results, as well as with available Lattice data.", "category": "hep-ph" }, { "text": "Tests for Sivers, Boer-Mulders and transversity distributions in\n difference cross sections in SIDIS: A major experimental program is presently underway to determine the Sivers,\nBoer-Mulders and transversity distributions, vital for understanding the\ninternal structure of the nucleon. To this end we consider the Sivers,\nBoer-Mulders and transversity azimuthal asymmetries of the difference cross\nsections of hadrons with opposite charges in SIDIS reactions with unpolarized\nand transversely polarized target l+N\\to l'+h+X, h=\\pi^\\pm, K^\\pm, h^\\pm. We\nshow that on deuteron target these asymmetries are particularly simple and\ndetermine the sum of the valence-quark Q_V=u_V+d_V transverse momentum\ndependent distributions without any contributions from the strange or other\nsea-quark functions. At present, data on these asymmetries are presented for\nthe integrated asymmetries i.e. the x_B- and z_h-dependent asymmetries. If data\nare available in small bins in Q^2, so that Q^2-dependence can be neglected,\nthese expressions simplify dramatically leading to remarkably simple and\npowerful tests of the simplifying assumptions used in extracting these\nfunctions from the data.", "category": "hep-ph" }, { "text": "Neutron-Electron EDM Correlations in Supersymmetry and Prospects for EDM\n Searches: Motivated by recent progress in experimental techniques of electric dipole\nmoment (EDM) measurements, we study correlations between the neutron and\nelectron EDMs in common supersymmetric models. These include minimal\nsupergravity (mSUGRA) with small CP phases, mSUGRA with a heavy SUSY spectrum,\nthe decoupling scenario and split SUSY. In most cases, the electron and neutron\nEDMs are found to be observable in the next round of EDM experiments. They\nexhibit certain correlation patterns. For example, if d_n ~ 10^{-27} e cm is\nfound, d_e is predicted to lie in the range 10^{-28}-10^{-29} e cm.", "category": "hep-ph" }, { "text": "Jet quenching in heavy ion collisions at LHC: We discuss the potential information about highly excited QCD-matter provided\nby medium-induced partonic energy loss, known as ``jet quenching''. In\nparticular, with its large acceptance hadronic and electromagnetic calorimetry,\nthe Compact Muon Solenoid detector at LHC collider is a promising device to\nstudy these effects. We present physics simulations of observables such as the\njet distribution with impact parameter, the azimuthal anisotropy of jet\nquenching, and the effects of b-quark energy loss on the high-mass dimuon\ncontinuum and secondary charmonium production.", "category": "hep-ph" }, { "text": "Interactions of the doubly charmed state $T_{cc} ^+$ with a hadronic\n medium: We investigate the absorption and production processes of this new state in a\nhadronic medium, considering the reactions $T_{cc}^+ \\pi, T_{cc}^+ \\rho\n\\rightarrow D^{(*)} D^{(*)} $ and the corresponding inverse reactions. We use\neffective field Lagrangians to account for the couplings between light and\nheavy mesons, and give special attention to the form factors in the vertices.\nWe calculate here for the first time the $ T_{cc}^+ - D - D^*$ form factor\nderived from QCD sum rules. The results are also obtained by testing widely\nutilized empirical form factors. The absorption cross sections are found to be\nlarger than the production ones. We compare our results with the only existing\nestimate of these quantities, presented in a work of J.~Hong, S.~Cho, T.~Song\nand S.~H.~Lee, in which the authors employed the quasi-free approximation. We\nfind cross sections which are one order of magnitude smaller.", "category": "hep-ph" }, { "text": "LUXE-NPOD: new physics searches with an optical dump at LUXE: We propose a novel way to search for feebly interacting massive particles,\nexploiting two properties of systems involving collisions between high energy\nelectrons and intense laser pulses. The first property is that the\nelectron-intense-laser collision results in a large flux of hard photons, as\nthe laser behaves effectively as a thick medium. The second property is that\nthe emitted photons free-stream inside the laser and thus for them the laser\nbehaves effectively as a very thin medium. Combining these two features implies\nthat the electron-intense-laser collision is an apparatus which can efficiently\nconvert UV electrons to a large flux of hard, co-linear photons. We further\npropose to direct this unique large and hard flux of photons onto a physical\ndump which in turn is capable of producing feebly interacting massive\nparticles, in a region of parameters that has never been probed before. We\ndenote this novel apparatus as ``optical dump'' or NPOD (new physics search\nwith optical dump). The proposed LUXE experiment at Eu.XFEL has all the\nrequired basic ingredients of the above experimental concept. We discuss how\nthis concept can be realized in practice by adding a detector after the last\nphysical dump of the experiment to reconstruct the two-photon decay product of\na new spin-0 particle. We show that even with a relatively short dump, the\nsearch can still be background free. Remarkably, even with a 40 TW laser, which\ncorresponds to the initial run, and definitely with a 350 TW laser, of the main\nrun with one year of data taking, LUXE-NPOD will be able to probe uncharted\nterritory of both models of pseudo-scalar and scalar fields, and in particular\nprobe natural of scalar theories for masses above 100 MeV.", "category": "hep-ph" }, { "text": "Selecting Supersymmetric String Scenarios From Sparticle Spectra: We approach the following question: if supersymmetry is discovered, how can\nwe select among different supersymmetric extensions of the Standard Model? In\nparticular, we perform an analysis of the sparticle spectrum in low-energy\nstring effective theories, asking which observables best distinguish various\nscenarios. We examine scenarios differing by the fundamental string scale and\nconcentrate on GUT and intermediate scale models. We scan over all parameters\n(two goldstino angles, tan beta and the gravitino mass) in each scenario,\nfinding ratios of sparticle masses that provide the maximum discrimination\nbetween them. The necessary accuracy for discrimination is determined in each\ncase. We find that the required accuracy on various sparticle mass ratios is at\nthe few percent level, a precision that may be achieved in future linear\ncolliders. We also map out phenomenologically viable regions of parameter\nspace.", "category": "hep-ph" }, { "text": "The D_4 flavor symmery in 3-3-1 model with neutral leptons: We construct a $D_4$ flavor model based on SU(3)_C X SU}(3_L X U(1)_X gauge\nsymmetry responsible for fermion masses and mixings. The neutrinos get small\nmasses from antisextets which are in a singlet and a doublet under $D_4$. If\nthe D_4 symmetry is violated as perturbation by a Higgs triplet under SU(3)_L\nand lying in {1}''' of D_4, the corresponding neutrino mass mixing matrix gets\nthe most general form. In this case, the model can fit the experimental data in\n2012 on neutrino masses and mixing. Our results show that the neutrino masses\nare naturally small and a little deviation from the tribimaximal neutrino\nmixing form can be realized. The quark masses and mixing matrix are also\ndiscussed. In the model under consideration, the CKM matrix can be different\nfrom the unit matrix. The scalar potential of the model is more simpler than\nthose of the model based on $S_3$ and $S_4$. Assignation of VEVs to antisextets\nleads to the mixing of the new gauge bosons and those in the Standard Model.\nThe mixing in the charged gauge bosons as well as the neutral gauge boson is\nconsidered.", "category": "hep-ph" }, { "text": "Stitching the Yukawa Quilt: We develop a systematic analysis of quark mass matrices which, starting with\nthe measured values of quark masses and mixing angles, allows for a model\nindependent search for all possible (symmetric or hermitian) mass matrices\nhaving texture zeroes at the unification scale. A survey of all six and five\ntexture zero structures yields a total of five possible solutions which may be\ndistinguished by improved measurements of the CKM matrix elements and which may\nreadily be extended to include lepton masses with the Georgi-Jarlskog texture.\nThe solutions naturally suggest a parameterisation for the mass matrices based\non a perturbative expansion and we present some speculations concerning the\norigin of such structure.", "category": "hep-ph" }, { "text": "Impact of the Recoil Scheme on the Accuracy of Angular-Ordered Parton\n Showers: In these proceedings we present three possible interpretations of the\nordering variable implemented in the Herwig7 angular-ordered parton shower.\nEach interpretation determines a different recoil-scheme prescription and we\nshow how it can impact the logarithmic accuracy of the algorithm. We also\npresent comparisons with LEP data.", "category": "hep-ph" }, { "text": "$\u03c0$-$J/\u03c8$ Correlation and Elliptic Flow Parameter $v_2$ of Charmed\n Mesons at RHIC Energy: We study the correlation between the trigger $\\pi$ and the associated\n$J/\\psi$ on near and away sides in Au+Au collisions at $\\sqrt{s_{NN}}=200$ GeV.\nIn the region of trigger momentum $p_t>4$ GeV/$c$, the $\\pi$ spectrum is\ncomposed of thermal-shower and shower-shower recombinations in the frame work\nof the recombination model. We consider the azimuthal anisotropy in the\nquenched hard parton distribution and then calculate the elliptic flow\nparameter $v_2$ of charmed mesons ($J/\\psi$, $D^0$ and $D_s$) for different\ncentralities.", "category": "hep-ph" }, { "text": "Dijet hadroproduction with rapidity gaps and QCD double logarithmic\n effects: We show that the hadroproduction of a pair of jets with large transverse\nenergy in the central region bounded by rapidity gaps is an ideal process to\nsee important double logarithmic QCD suppression effects. We compute the cross\nsections for both exclusive and inclusive double-diffractive dijet production\nat Tevatron and LHC energies for a range of rapidity configurations.", "category": "hep-ph" }, { "text": "Sign problem and the chiral spiral on the finite-density lattice: We investigate the sign problem of the fermion determinant at finite baryon\ndensity in (1+1) dimensions, in which the ground state in the chiral limit\nshould be free from the sign problem by forming a chiral spiral. To confirm it,\nwe evaluate the fermion determinant in the continuum theory at the one-loop\nlevel and find that the determinant becomes real as expected. The conventional\nlattice formulation to implement a chemical potential is, however, not\ncompatible with the spiral transformation. We discuss an alternative of the\nfinite-density formulation and numerically verify the chiral spiral on the\nfinite-density lattice.", "category": "hep-ph" }, { "text": "Cogenesis of Baryon Asymmetry and Gravitational Dark Matter from\n Primordial Black Holes: We propose a scenario where dark matter (DM) with a wide mass range from a\nfew keV to PeV can be produced solely from evaporating primordial black holes\n(PBH), while being consistent with the required free streaming length for\nstructure formation. If DM does not have any other interactions apart from\ngravity and the universe has a PBH dominated phase at early epoch, then PBH\nevaporation typically leads to overproduction of DM in this mass range. By\nincorporating this gravitational DM within a Type-I seesaw scenario with three\nright handed neutrinos (RHN), we bring the abundance of PBH generated DM within\nobserved limits by late entropy injection due to decay of one of the RHNs,\nacting as the diluter. The diluter, due to its feeble coupling with the bath\nparticles, gets produced primarily from the PBH evaporation thereby leading to\nthe second stage of early matter domination after the end of PBH dominated era.\nThe other two RHNs contribute to the origin of light neutrino mass and also\nlead to the observed baryon asymmetry via leptogenesis with contributions from\nboth thermally and PBH generated RHNs. The criteria of DM relic and baryon\nasymmetry can be satisfied simultaneously if DM mass gets restricted to a\nballpark in the MeV-GeV regime with the requirement of resonant leptogenesis\nfor heavier DM mass in order to survive the large entropy dilution at late\nepochs.", "category": "hep-ph" }, { "text": "Split-SUSY dark matter in light of direct detection limits: We examine the present and future XENON limits on the neutralino dark matter\nin split supersymmetry (split-SUSY). Through a scan over the parameter space\nunder the current constraints from collider experiments and the WMAP\nmeasurement of the dark matter relic density, we find that in the allowed\nparameter space a large part has been excluded by the present XENON100 limits\nand a further largish part can be covered by the future exposure (6000 kg-day).\nIn case of unobservation of dark matter with such an exposure in the future,\nthe lightest neutralino will remain bino-like and its annihilation is mainly\nthrough exchanging the SM-like Higgs boson in order to get the required relic\ndensity.", "category": "hep-ph" }, { "text": "Relativistic description of the double charmonium production in $e^+e^-$\n annihilation: New evaluation of the relativistic effects in the double production of\n$S$-wave charmonium states is performed on the basis of perturbative QCD and\nthe relativistic quark model. The main improvement consists in the exact\naccount of properties of the relativistic meson wave functions. For the gluon\nand quark propagators entering the production vertex function we use a\ntruncated expansion in the ratio of the relative quark momenta to the\ncenter-of-mass energy $\\sqrt{s}$ up to the second order. The exact relativistic\ntreatment of the wave functions makes all such second order terms convergent,\nthus allowing the reliable calculation of their contributions to the production\ncross section. Compared to the nonrelativistic calculation we obtain a\nsignificant increase of the cross sections for the $S$-wave double charmonium\nproduction. This brings new theoretical results in good agreement with the\navailable experimental data.", "category": "hep-ph" }, { "text": "B^0_{d,s} - \\bar{B}^0_{d,s} mass-differences from QCD spectral sum rules: We present the first QCD spectral sum rules analysis of the SU(3) breaking\nparameter \\xi and an improved estimate of the renormalization group invariant\n(RGI) bag constant \\hat{B}_{B_q} both entering into the B^0_{d,s} -\n\\bar{B}^0_{d,s} mass-differences. The averages of the results from the Laplace\nand moment sum rules to order \\alpha_s are f_B\\sqrt{\\hat B_B} \\simeq (247 \\pm\n59) MeV and \\xi \\equiv f_{B_s} \\sqrt{\\hat B_{B_s}} / f_{B} \\sqrt{\\hat B_{B}}\n\\simeq (1.18\\pm 0.03), in units where f_\\pi=130.7 MeV. Combined with the\nexperimental data on the mass-differences \\Delta M_{d,s}, one obtains the\nconstraint on the CKM weak mixing angle |V_{ts}/V_{td}|^2 > 20.0 (1.1).\nAlternatively, using the weak mixing angle from the analysis of the unitarity\ntriangle and the data on \\Delta M_d, one predicts \\Delta M_s=18.6 (2.2) ps^{-1}\nin agreement with the present experimental lower bound and within the reach of\nTevatron 2.", "category": "hep-ph" }, { "text": "Gravitational waves as a probe of SUSY scale: We investigate the sources of the Hubble-induced mass for a flat direction in\nsupersymmetric theories and show that the sign of the Hubble-induced mass\ngenerally changes just after the end of inflation. This implies that global\ncosmic strings generally form after the end of inflation in most supersymmetric\nmodels, including the Minimal Supersymmetric Standard Model. The cosmic strings\nemit gravitational waves whose frequency corresponds to the Hubble scale, until\nthey disappear when the Hubble parameter decreases down to the soft mass of the\nflat direction. As a result, the peak frequency of gravitational waves is\nrelated to the supersymmetric scale. The observation of this gravitational wave\nsignal will give us information of supersymmetric scale and reheating\ntemperature.", "category": "hep-ph" }, { "text": "The $\u03b7- \u03b7'$ Mixing Angle Revisited: The value of the $\\eta - \\eta'$ mixing angle $\\theta_P$ is phenomenologically\ndeduced from a rather exhaustive and up-to-date analysis of data including\nstrong decays of tensor and higher-spin mesons, electromagnetic decays of\nvector and pseudoscalar mesons, $J/\\psi$ decays into a vector and a\npseudoscalar meson, and other transitions. A value of $\\theta_P$ between\n$-17^\\circ$ and $-13^\\circ$ is consistent with all the present experimental\nevidence and the average $\\theta_P=-15.5^\\circ\\pm 1.3^\\circ$ seems to be\nfavoured.", "category": "hep-ph" }, { "text": "Symmetries in $B \\to D^* \\ell \u03bd$ angular observables: We apply the formalism of amplitude symmetries to the angular distribution of\nthe decays $B \\to D^* \\ell \\nu$ for $\\ell=e,\\mu,\\tau$. We show that the angular\nobservables used to describe the distribution of this class of decays are not\nindependent in absence of New Physics contributing to tensor operators. We\nderive sets of relations among the angular coefficients of the decay\ndistribution for the massless and massive lepton cases which can be used to\nprobe in a very general way the consistency among the angular observables and\nthe underlying New Physics at work. We use these relations to access the\nlongitudinal polarisation fraction of the $D^*$ using different angular\ncoefficients from the ones used by Belle experiment. This in the near future\ncan provide an alternative strategy to measure $F_L^{D^*}$ in $B \\to D^* \\tau\n\\nu$ and to understand the relatively high value measured by the Belle\nexperiment. Using the same symmetries, we identify three observables which may\nexhibit a tension if the experimental value of $F_L^{D^*}$ remains high. We\ndiscuss how these relations can be exploited for binned measurements. We also\npropose a new observable that could test for specific scenarios of New Physics\ngenerated by light right-handed neutrinos. Finally we study the prospects of\ntesting these relations based on the projected experimental sensitivity of new\nexperiments.", "category": "hep-ph" }, { "text": "Planar three-loop master integrals for $2 \\to 2$ processes with one\n external massive particle: We present analytic results for the two tennis-court integral families\nrelevant to $2\\to2$ scattering processes involving one massive external\nparticle and massless propagators in terms of Goncharov polylogarithms of up to\ntranscendental weight six. We also present analytic results for physical\nkinematics for the ladder-box family and the two tennis-court families in terms\nof real-valued polylogarithmic functions, making our solutions well-suited for\nphenomenological applications.", "category": "hep-ph" }, { "text": "Local spatial densities for composite spin-3/2 systems: The definition of local spatial densities by using sharply localized\none-particle states is applied to spin-3/2 systems. Matrix elements of the\nelectromagnetic current and the energy-momentum tensor are considered and\nintegral expressions of associated spatial distributions in terms of form\nfactors are derived.", "category": "hep-ph" }, { "text": "Neutrality of the color-flavor-locked phase in a Dyson-Schwinger\n approach: The role of neutrality constraints for the phase structure of QCD at\nnon-vanishing chemical potentials is studied within a self-consistent\ntruncation scheme for the Dyson-Schwinger equation of the quark propagator in\nLandau gauge. We find the (approximate) color-flavor-locked phase to be\nenergetically preferred at all potentially relevant densities and for physical\nvalues of the quark masses. We furthermore observe the impossibility to define\nthis phase by residual global symmetries and discuss the role of chemical\npotentials.", "category": "hep-ph" }, { "text": "Graviton-mediated dark matter model explanation the DAMPE electron\n excess and search at $e^+e^-$ colliders: The very recent result of the DAMPE cosmic ray spectrum of electrons shows a\nnarrow bump above the background at around 1.4 TeV. We attempt to explain the\nDAMPE electron excess in a simplified Kaluza-Klein graviton-mediated dark\nmatter model, in which the graviton only interacts with leptons and dark\nmatter. The related phenomenological discussions are given and this simplified\ngraviton-mediated dark matter model has the potential to be cross-tested in\nfuture lepton collider experiments.", "category": "hep-ph" }, { "text": "Non-perturbative effects for dark sectors with QCD portals: In this work, we consider a class of dark matter (DM) models where the DM\ndoes not directly interact with the Standard Model (SM) particles at the\ntree-level. Therefore, the coannihilation mechanism is crucial in achieving the\ncorrect DM relic abundance, which in turn requires the coannihilating partner\nto be close in mass to the actual DM particle. In our systematisation of the\nmodels' class, the mediator and the coannihilation partner are assumed to be\ncharged under QCD interactions. This last feature calls for a scrutiny of\nnon-perturbative effects, namely Sommerfeld factors and bound-state formation,\non the annihilations of the colored partner. Such non-perturbative effects are\nillustrated with an example model comprising a scalar leptoquark mediator, a\nDirac vector-like fermion coannihilation partner, and a singlet DM fermion.\nPhenomenological features of this model, namely DM direct and indirect\ndetection prospects, collider implications, and impact on the muon anomalous\nmagnetic moment, are discussed.", "category": "hep-ph" }, { "text": "Universality test of the charged Higgs boson couplings at the LHC and at\n B factories: Many extensions of the Standard Model (SM) of particle physics predict the\nexistence of charged Higgs bosons with substantial couplings to SM particles,\nwhich would render them observable both directly at the LHC and indirectly at\nB-factories. For example, the charged Higgs boson couplings to fermions in two\ndoublet Higgs models of type II, are proportional to the ratio of the two Higgs\ndoublet vacuum expectation values (tan(beta)) and fermionic mass factors and\ncould thus be substantial at large tan(beta) and/or for heavy fermions. In this\nwork we perform a model-independent study of the charged Higgs boson couplings\nat the LHC and at B-factories for large values of tan(beta). We have shown that\nat high luminosity it is possible to measure the couplings of a charged Higgs\nboson to the third generation of quarks up to an accuracy of 10%. We further\nargue that by combining the possible measurements of the LHC and the\nB-factories, it is possible to perform a universality test of charged Higgs\nboson couplings to quarks.", "category": "hep-ph" }, { "text": "The hunt for sub-GeV dark matter at neutrino facilities: a survey of\n past and present experiments: We survey the sensitivity of past and present neutrino experiments to MeV-GeV\nscale dark matter, and find that these experiments possess novel sensitivity\nthat has not yet fully explored. NO$\\nu$A and BEBC are found to rule out the\nscalar thermal target for dark matter masses between 10 MeV to 100 MeV with\nexisting data, while CHARM-II and MINER$\\nu$A place somewhat weaker limits.\nThese limits can be dramatically improved by off-axis searches using the NuMI\nbeamline and the MicroBooNE, MiniBooNE or ICARUS detectors, and can even begin\nto probe the Majorana thermal target. We conclude that past and present\nneutrino facilities can search for light dark matter concurrently with their\nneutrino program and reach a competitive sensitivity to proposed future\nexperiments.", "category": "hep-ph" }, { "text": "Molecular states from\n $\u03a3^{(*)}_c\\bar{D}^{(*)}-\u039b_c\\bar{D}^{(*)}$ interaction: In this work, we systemically investigate the molecular states from the\n$\\Sigma^{(*)}_c\\bar{D}^{(*)}-\\Lambda_c\\bar{D}^{(*)}$ interaction with the help\nof the Lagrangians with heavy quark and chiral symmetries in a quasipotential\nBethe-Salpeter equation (qBSE) approach. The molecular states are produced from\nisodoublet (I=1/2) $\\Sigma_c\\bar{D}$ interaction with spin parity $J^P=1/2^-$\nand $\\Sigma_c\\bar{D}^*$ interaction with $1/2^-$ and $ 3/2^-$. Their masses and\nwidths are consistent with the $P_c(4312)$, $P_c(4440)$ and $P_c(4457)$\nobserved at LHCb. The states, $\\Sigma_c^*\\bar{D}^*(1/2^-)$,\n$\\Sigma_c^*\\bar{D}^*(3/2^-)$ and $\\Sigma^*_c\\bar{D}(3/2^-)$, are also produced\nwith the same parameters. The isodoublet $\\Sigma_c^*\\bar{D}^*$ interaction with\n$5/2^-$, as well as the isoquartet (I=3/2) $\\Sigma_c\\bar{D}^*$ interactions\nwith $1/2^-$ and $3/2^-$, $\\Sigma_c^*\\bar{D}^*$ interaction with $3/2^-$ and\n$5/2^-$, are also attractive while very large cutoff is required to produce a\nmolecular state. We also investigate the origin of the widths of these\nmolecular states in the same qBSE frame. The $\\Lambda\\bar{D}^*$ channel is\ndominant in the decays of the states, $\\Sigma_c\\bar{D}^*(1/2^-)$,\n$\\Sigma_c\\bar{D}^*(3/2^-)$, $\\Sigma_c^*\\bar{D}(3/2^-)$, and\n$\\Sigma_c\\bar{D}(1/2^-)$. The $\\Sigma^*_c\\bar{D}^*(1/2^-)$ state has large\ncoupling to $\\Sigma_c\\bar{D}$ channel while the $\\Sigma_c\\bar{D}^*$,\n$\\Sigma^*_c\\bar{D}$ and $\\Lambda_c\\bar{D}^*$ channels provide similar\ncontributions to the width of the $\\Sigma^*_c\\bar{D}^*(3/2^-)$ state. These\nresults will be helpful to understand the current LHCb experimental results,\nand the three predicted states and the decay pattern of these hidden-charmed\nmolecular pentaquarks can be checked in future experiments.", "category": "hep-ph" }, { "text": "Gravitational wave spectra from oscillon formation after inflation: We systematically investigate the preheating behavior of single field\ninflation with an oscillon-supporting potential. We compute the properties of\nthe emitted gravitational waves (GWs) and the number density and\ncharacteristics of the produced oscillons. By performing numerical simulations\nfor a variety of potential types, we divide the analyzed potentials in two\nfamilies, each of them containing potentials with varying large- or small-field\ndependence. We find that the shape and amplitude of the emitted GW spectrum\nhave a universal feature, with the peak around the physical wavenumber $k/a\n\\sim m$ at the inflaton oscillation period, irrespective of the exact potential\nshape. This can be used as a smoking-gun for deducing the existence of a\nviolent preheating phase and possible oscillon formation after inflation.\nDespite this apparent universality, we find differences in the shape of the\nemitted GW spectra between the two potential families, leading to\ndiscriminating features between them. In particular, all potentials show the\nemergence of a two-peak structure in the GW spectrum, arising at the time of\noscillon formation. However, potentials exhibiting efficient parametric\nresonance tend to smear out this structure and by the end of the simulation the\nGW spectrum exhibits a single broad peak. We further compute the properties of\nthe produced oscillons for each potential, finding differences in the number\ndensity and size distribution of stable oscillons and transient overdensities.\nWe perform a linear fluctuation analysis and use Floquet charts to relate the\nresults of our simulations to the structure of parametric resonance. We find\nthat the growth rate of scalar perturbations and the associated oscillon\nformation time are sensitive to the small-field potential shape while the\nmacroscopic physical properties of oscillons (e.g. total number) depend on the\nlarge-field potential shape.", "category": "hep-ph" }, { "text": "Final-State Phases in $B \\to D \u03c0, D^* \u03c0$, and $D \u03c1$ Decays: The final-state phases in $\\bar{B} \\to D \\pi, D^* \\pi$, and $D \\rho$ decays\nappear to follow a pattern similar to those in $D \\to \\bar{K} \\pi$, $\\bar{K}^*\n\\pi$, and $\\bar{K} \\rho$ decays. Each set of processes is characterized by\nthree charge states but only two independent amplitudes, so the amplitudes form\ntriangles in the complex plane. For the first two sets the triangles appear to\nhave non-zero area, while for the $D \\rho$ or $\\bar{K} \\rho$ decays the areas\nof the triangles are consistent with zero. Following an earlier discussion of\nthis behavior for $D$ decays, a similar analysis is performed for B decays, and\nthe relative phases and magnitudes of contributing amplitudes are determined.\nThe significance of recent results on $\\ob \\to D^{(*)0} \\bar{K}^{(*)0}$ is\nnoted. Open theoretical and experimental questions are indicated.", "category": "hep-ph" }, { "text": "Higgs inflation in a radiative seesaw model: We investigate a simple model to explain inflation, neutrino masses and dark\nmatter simultaneously. This is based on the so-called radiative seesaw model\nproposed by Ma in order to explain neutrino masses and dark matter by\nintroducing a $Z_2$-odd isospin doublet scalar field and $Z_2$-odd right-handed\nneutrinos. We study the possibility that the Higgs boson as well as neutral\ncomponents of the $Z_2$-odd scalar doublet field can satisfy conditions from\nslow-roll inflation and vacuum stability up to the inflation scale. We find\nthat a part of parameter regions where these scalar fields can play a role of\nan inflaton is compatible with the current data from neutrino experiments and\nthose of the dark matter abundance as well as the direct search results. A\nphenomenological consequence of this scenario results in a specific mass\nspectrum of scalar bosons, which can be tested at the LHC, the International\nLinear Collider and the Compact Linear Collider.", "category": "hep-ph" }, { "text": "On power corrections to event shapes: Recent work on the theme of power corrections in perturbative QCD is briefly\nreviewed, with an emphasis on event shapes in e+ e- annihilation. The\nfactorization of soft gluon effects is the main tool: it leads to resummation,\nand thus highlights the limitations of perturbation theory, pointing to\nnonperturbative corrections whose size can be estimated. Power corrections can\nbe resummed into shape functions, for which QCD--based models are available.\nTheoretical progress is closing in on the nonperturbative frontier.", "category": "hep-ph" }, { "text": "Low-energy meson phenomenology with Resonance Chiral Lagrangians: The low energy behaviour of Quantum Chromodynamics makes unreliable an\nexpansion in terms of its coupling strength, since nothing guarantees the\nconvergence of such expansion. To overcomer such difficulty one resorts to\nLattice QCD or Effective Field Theories. In this thesis we compute hadronic\nprocesses at low energies, using Resonance Chiral Lagrangians as the effective\ntheory of QCD. The processes we study are important background on the search\nfor Lepton Flavor Violation, Lepton Universality Violation, Lepton Number\nViolation, Second Class Currents and study the Hadronic light-by-light\ncontribution to the Anomalous Magnetic Moment of the muon. All such processes\nare of great interest since all of them are to be studied with an increased\nprecision in the very near future by different experiments.", "category": "hep-ph" }, { "text": "Improved bounds on non-luminous matter in solar orbit: We improve, using a larger set of observations including Voyager 2 Neptune\nflyby data, previous bounds on the amount of dark matter (DM) trapped in a\nspherically symmetric distribution about the sun. We bound DM by noting that\nsuch a distribution would increase the effective mass of the sun as seen by the\nouter planets and by finding the uncertainty in that effective mass for Uranus\nand Neptune in fits to the JPL Developmental Ephermeris residuals, including\noptical data and those two planets' Voyager 2 flybys. We extend our previous\nprocedure by fitting more parameters of the developmental ephemerides.\nAdditionally, we present here the values for Pioneer 10 and 11 and Voyager 1\nand 2 Jupiter ranging normal points (and incorporate these data as well). Our\nprincipal result is to limit DM in spherically symmetric distributions in orbit\nabout the sun interior to Neptune's orbit to less than an earth mass and\ninterior to Uranus' orbit to about 1/6 of an earth's mass.", "category": "hep-ph" }, { "text": "Third-order non-Coulomb correction to the S-wave quarkonium wave\n functions at the origin: We compute the third-order correction to the S-wave quarkonium wave functions\n|\\psi_n(0)|^2 at the origin from non-Coulomb potentials in the effective\nnon-relativistic Lagrangian. Together with previous results on the Coulomb\ncorrection and the ultrasoft correction computed in a companion paper, this\ncompletes the third-order calculation up to a few unknown matching\ncoefficients. Numerical estimates of the new correction for bottomonium and\ntoponium are given.", "category": "hep-ph" }, { "text": "Consistent Scenarios for Cosmic-Ray Excesses from Sommerfeld-Enhanced\n Dark Matter Annihilation: Anomalies in direct and indirect detection have motivated models of dark\nmatter consisting of a multiplet of nearly-degenerate states, coupled by a new\nGeV-scale interaction. We perform a careful analysis of the thermal freezeout\nof dark matter annihilation in such a scenario. We compute the range of \"boost\nfactors\" arising from Sommerfeld enhancement in the local halo for models which\nproduce the correct relic density, and show the effect of including constraints\non the saturated enhancement from the cosmic microwave background (CMB). We\nfind that boost factors from Sommerfeld enhancement of up to ~800 are possible\nin the local halo. When the CMB bounds on the saturated enhancement are\napplied, the maximal boost factor is reduced to ~400 for 1-2 TeV dark matter\nand sub-GeV force carriers, but remains large enough to explain the observed\nFermi and PAMELA electronic signals. We describe regions in the DM mass-boost\nfactor plane where the cosmic ray data is well fit for a range of final states,\nand show that Sommerfeld enhancement alone is enough to provide the large\nannihilation cross sections required to fit the data, although for light\nmediator masses (less than ~200 MeV) there is tension with the CMB constraints\nin the absence of astrophysical boost factors from substructure. Additionally,\nwe consider the circumstances under which WIMPonium formation is relevant and\nfind for heavy WIMPs (greater than ~2 TeV) and soft-spectrum annihilation\nchannels it can be an important consideration; we find regions with dark matter\nmass greater than 2.8 TeV that are consistent with the CMB bounds and have\n~600-700 present-day boost factors.", "category": "hep-ph" }, { "text": "CP Violation in the B System: Strategies for extracting CKM phases from non-leptonic $B$ decays are\nreviewed briefly. Both general aspects and some recent developments including\nCP-violating asymmetries, the $B_s$ system in light of a possible width\ndifference $\\Delta\\Gamma_s$, and triangle relations among $B$ decay amplitudes\nare discussed. The role of electroweak penguins in these strategies is\nillustrated briefly.", "category": "hep-ph" }, { "text": "Tracking down hyper-boosted top quarks: The identification of hadronically decaying heavy states, such as vector\nbosons, the Higgs, or the top quark, produced with large transverse boosts has\nbeen and will continue to be a central focus of the jet physics program at the\nLarge Hadron Collider (LHC). At a future hadron collider working at an\norder-of-magnitude larger energy than the LHC, these heavy states would be\neasily produced with transverse boosts of several TeV. At these energies, their\ndecay products will be separated by angular scales comparable to individual\ncalorimeter cells, making the current jet substructure identification\ntechniques for hadronic decay modes not directly employable. In addition, at\nthe high energy and luminosity projected at a future hadron collider, there\nwill be numerous sources for contamination including initial- and final-state\nradiation, underlying event, or pile-up which must be mitigated. We propose a\nsimple strategy to tag such \"hyper-boosted\" objects that defines jets with\nradii that scale inversely proportional to their transverse boost and combines\nthe standard calorimetric information with charged track-based observables. By\nmeans of a fast detector simulation, we apply it to top quark identification\nand demonstrate that our method efficiently discriminates hadronically decaying\ntop quarks from light QCD jets up to transverse boosts of 20 TeV. Our results\nopen the way to tagging heavy objects with energies in the multi-TeV range at\npresent and future hadron colliders.", "category": "hep-ph" }, { "text": "Some tests for the helicity structure of the pomeron in $ep$ collisions: We discuss the reaction $e p \\to e \\tilde{p} X$ in the one-photon exchange\napproximation, where it is in essence the reaction $\\gamma^{*} p \\to \\tilde{p}\nX$. A large rapidity gap is required between the particle or particles of the\nproton remnant $\\tilde{p}$ and those of $X$. We define a suitable azimuthal\nangle $\\varphi$ between a leptonic and a hadronic plane. The dependence of the\ncross section on $\\varphi$ is given explicitly and can be used to extract cross\nsections and interference terms for the reaction $\\gamma^{*} p \\to \\tilde{p} X$\ncorresponding to the various helicities of the virtual photon $\\gamma^{*}$. The\ninterference terms can be used to test models for the large rapidity gap events\nin a sensitive way. We discuss in detail models with factorizing Pomeron\nexchange and in particular the Donnachie-Landshoff Pomeron model. We make some\nremarks on soft colour exchange models and on possible effects of QCD\nbackground vacuum fields. We conclude with a suggestion to look for Odderon\nexchange in exclusive deep inelastic high energy reactions like $\\gamma^{*} p\n\\to \\tilde{p} \\pi^{0}$ and $\\gamma^{*} p \\to \\tilde{p} \\eta$.", "category": "hep-ph" }, { "text": "Simple and robust method for search Dark Matter particles and measuring\n their properties at ILC in various models of DM: I suggest simple method for the search of Dark Matter particles and some\nrelated particles which allows to measure reliably their mass and spin in a\nwide class of models for Dark Matter.", "category": "hep-ph" }, { "text": "Axion and Right-handed Neutrino in the Minimal SUSY SO(10) Model: The connection between the axion and right-handed neutrinos is explored in\nthe framework of the minimal SUSY SO(10) model. The former is related to the\nPeccei-Quinn (PQ) solution to the strong CP problem and the latter is to the\nlight Majorana neutrinos through the see-saw mechanism. In this model, a\nrelative phase between $({\\bf 10,1,3}) (\\equiv {\\bf \\bar{\\Delta}}_R) \\subset\n{\\bf \\bar{126}}$ and $({\\bf \\bar{10},1,3}) (\\equiv {\\bf \\Delta}_R) \\subset {\\bf\n126}$ multiplets of ${\\rm SU}(4) \\times {\\rm SU}(2)_L \\times {\\rm SU}(2)_R\n\\subset {\\rm SO}(10)$ becomes a physical degree of freedom identified with the\naxion. Then, the PQ symmetry breaking scale ($\\Lambda_{\\rm PQ}$) and the $B-L$\nsymmetry breaking scale ($\\Lambda_{\\rm B-L}$) coincide through the VEV of ${\\bf\n\\bar{\\Delta}}_R$. The scalar partner of the lightest right-handed neutrino is\nregarded as the inflaton, which gives a consistent density fluctuation for the\nCMB.", "category": "hep-ph" }, { "text": "Dark matter stability from non-Abelian discrete flavor symmetries: We present a mechanism for the dark matter stability in the framework of a\nnon-Abelian avour symmetry renormalizable model. The same non-abelian discrete\navor symmetry which accounts for the observed pattern of neutrino oscillations,\nspontaneously breaks to a Z2 subgroup which renders DM stable. The simplest\nscheme leads to a scalar doublet DM potentially detectable in nuclear recoil\nexperiments, inverse neutrino mass hierarchy, hence a neutrinoless double beta\ndecay rate accessible to upcoming searches.", "category": "hep-ph" }, { "text": "Empirical Parameterization of Nucleon-Nucleon Elastic Scattering\n Amplitude at High Beam Momenta for Glauber Calculations and Monte Carlo\n Simulations: A parameterization of the nucleon-nucleon elastic scattering amplitude is\nneeded for future experiments with nucleon and nuclear beams in the beam\nmomentum range of 2 -- 50 GeV/c/nucleon. There are many parameterizations of\nthe amplitude at $P_{lab} >$ 25--50 GeV/c, and at $P_{lab} \\leq$ 5 GeV/c. Our\npaper is aimed to cover the range between 5 -- 50 GeV/c.\n The amplitude is used in Glauber calculations of various cross sections and\nMonte Carlo simulations of nucleon-nucleon scatterings. Usually, the\ndifferential nucleon-nucleon elastic scattering cross sections are described by\nan exponential expression. Corresponding experimental data on $pp$ interactions\nat $|t|>$ 0.005 (GeV/c)$^2$ and $|t|\\leq$ 0.125 (GeV/c)$^2$ have been fit. We\npropose formulae to approximate the beam momentum dependence of these\nparameters in the momentum range considered. The same was done for $np$\ninteractions at $|t|\\leq$ 0.5 (GeV/c)$^2$. Expressions for the momentum\ndependence of the total and elastic cross sections, and the ratio of real to\nimaginary parts of the amplitude at zero momentum transfer are also given for\n$pp$ and $np$ collisions. These results are sufficient for a first\napproximation of the Glauber calculations. For more exact calculations we fit\nthe data at $|t|>$ 0.005 (GeV/c)$^2$ without restrictions on the maximum value\nof $|t|$ using an expression based on two coherent exponential. The parameters\nof the fits are found for the beam momentum range 2 -- 50 GeV/c.", "category": "hep-ph" }, { "text": "Can the Super-Kamiokande Atmospheric Data Predict the Solar Neutrino\n Deficit ?: In this Letter we show that the evidence for neutrino oscillations from the\nSuper-Kamiokande atmospheric neutrino data fully determines the 3x3\nneutrino-oscillations mixing matrix and predicts an energy independent solar\nneutrino deficit at the level of 45%. This corresponds to a ratio of measured\nto predicted neutrino flux of R_e^{Solar} = 0.55, in good agreement with the\nexperimental results. We achieve this result within the framework of a minimal,\nthree-generations neutrino mixing, with mass squared differences of dM^2 = 0.45\neV^2 and dm^2 = O(10^-3) eV^2. The mixing matrix derived here is characterized\nby the mixing angles theta = 35.1, beta = 5.5, and psi = 23.3, and a vanishing\nCP-violating phase, delta = 0.", "category": "hep-ph" }, { "text": "Evolution of gluon TMDs from small to moderate x: Recently we obtained an evolution equation of gluon TMDs, which addresses a\nproblem of unification of different kinematic regimes. It describes evolution\nin the whole range of Bjorken $x_B$ and the whole range of transverse momentum\n$k_\\perp$. In this notes I study different limits of this evolution equation\nand show how it yields several well-known and some previously unknown results.", "category": "hep-ph" }, { "text": "Reconstructing events with missing transverse momentum at the LHC and\n its application to spin measurement: In this article we discuss the measurement of spin at the LHC, in events with\ntwo unknown four-momenta. Central to this problem is the identification of\nspin-dependent kinematic variables and the construction of a statistical test\nthat can distinguish between different spin hypotheses. We propose a method for\nreconstructing kinematic variables that depend upon the unknown momenta. The\nmethod is based upon a probabilistic reconstruction of each event, given the\nmasses of the final and intermediate states and the cross-section of the\nassumed hypothesis. We demonstrate that this method can distinguish between two\nspin hypotheses for a specific process, even after mass uncertainties and\nStandard Model backgrounds are taken into account. We compare our method with\nanother that only utilises the observable momenta of each event. We will show\nthat our method permits an improved discrimination between hypotheses, with a\nreduced probability of error.", "category": "hep-ph" }, { "text": "Probing New Physics with $\\bar B \\to \u03c1(770) \\, \\ell^- \\bar \u03bd_\\ell$\n and $\\bar B \\to a_1(1260) \\, \\ell^- \\bar \u03bd_\\ell$: The $B$ meson semileptonic modes to $\\rho(770)$ and $a_1 (1260)$ are useful\nto pin down possible non Standard Model effects. The 4d differential $\\bar B\n\\to \\rho(\\pi \\pi) \\ell^- \\bar \\nu_\\ell$ and $ \\bar B \\to a_1 (\\rho \\pi) \\ell^-\n\\bar \\nu_\\ell$ decay distributions are computed in SM and in extensions\ninvolving new Lepton Flavour Universality violating semileptonic $b \\to u$\noperators. The Large Energy limit for the light meson is also considered for\nboth modes. The new effective couplings are constrained using the available\ndata, and several observables in $\\bar B \\to \\rho(\\pi\\pi) \\ell^- \\bar \\nu_\\ell$\nin which NP effects can be better identified are selected, using the angular\ncoefficient functions. The complementary role of $\\bar B \\to \\rho(\\pi \\pi)\n\\ell^- \\bar \\nu_\\ell$ and $\\bar B \\to a_1 (\\rho \\pi) \\ell^- \\bar \\nu_\\ell$ is\ndiscussed.", "category": "hep-ph" }, { "text": "Dark Matter Phenomenology: I review recent developments in the direct and indirect detection of dark\nmatter and new candidates beyond the WIMP paradigm.", "category": "hep-ph" }, { "text": "Extra $Z^\\prime$s and $W^\\prime$s in Heterotic--String Derived Models: The ATLAS collaboration recently recorded possible excess in the di--boson\nproduction at the di--boson invariant mass at around 2 TeV. Such an excess may\nbe produced if there exist additional $Z^\\prime$ and/or $W^\\prime$ at that\nscale. We survey the extra $Z^\\prime$s and $W^\\prime$s that may arise from\nsemi--realistic heterotic string vacua in the free fermionic formulation in\nseven distinct cases including: $U(1)_{Z^\\prime}\\in SO(10)$; family universal\n$U(1)_{Z^\\prime}$ not in $SO(10)$; non--universal $U(1)_{Z^\\prime}$; hidden\nsector $U(1)$ symmetries and kinetic mixing; left--right symmetric models;\nPati--Salam models; leptophobic and custodial symmetries. Each case has a\ndistinct signature associated with the extra symmetry breaking scale. In one of\nthe cases we explore the discovery potential at the LHC using resonant\nleptoproduction. Existence of extra vector boson with the reported properties\nwill significantly constrain the space of allowed string vacua.", "category": "hep-ph" }, { "text": "The evolution of parton distributions beyond leading order: the singlet\n case: A complete description of the calculation of anomalous dimensions (GLAP\nsplitting functions) is given for parton distributions which appear in\nspace-like processes. The calculation is performed in the light-cone gauge. The\nresults are in agreement with the previous results of Furmanski and Petronzio.", "category": "hep-ph" }, { "text": "The AdS/CFT Correspondence and Light-Front QCD: We identify an invariant light-front coordinate $\\zeta$ which allows the\nseparation of the dynamics of quark and gluon binding from the kinematics of\nconstituent spin and internal orbital angular momentum. The result is a\nsingle-variable light-front Schrodinger equation for QCD which determines the\neigenspectrum and the light-front wavefunctions of hadrons for general spin and\norbital angular momentum. This frame-independent light-front wave equation is\nequivalent to the equations of motion which describe the propagation of\nspin-$J$ modes on anti-de Sitter (AdS) space. Light-front holography is a\nremarkable feature of AdS/CFT: it allows hadronic amplitudes in the AdS fifth\ndimension to be mapped to frame-independent light-front wavefunctions of\nhadrons in physical space-time, thus providing a relativistic description of\nhadrons at the amplitude level. In principle, the model can be systematically\nimproved by diagonalizing the full QCD light-front Hamiltonian on the AdS/QCD\nbasis. Quark and gluon hadronization can be computed at the amplitude level by\nconvoluting the off-shell $T$ matrix calculated from the QCD light-front\nHamiltonian with the hadronic light-front wavefunctions. We also note the\ndistinction between static observables such as the probability distributions\ncomputed from the square of the light-front wavefunctions versus dynamical\nobservables such as the structure functions and the leading-twist single-spin\nasymmetries measured in deep inelastic scattering which include the effects of\ninitial and final-state interactions.", "category": "hep-ph" }, { "text": "Mass Measurement in Boosted Decay Chains with Missing Energy: We explore a novel method of mass reconstruction in events with missing\ntransverse momentum at hadron colliders. In events with sizeable boost factors\nin the final steps of dual multi-stage decay chains, the missing energy\nparticles may each be approximately collinear with a visible standard model\nparticle, spanning a narrow \"MET-cone.\" We exploit this collinear\napproximation, when applicable, to reconstruct the masses of exotica.", "category": "hep-ph" }, { "text": "Infrared Effects of Ultraviolet Operators on Dark Matter Freeze-In: Dark matter (DM) that interacts too weakly with the Standard Model (SM) to\nreach full thermodynamic equilibrium can be still be created in significant\namounts by rare SM collisions. This mechanism, called freeze-in, can proceed\nthrough a renormalizable connector operator with a very small coefficient, or a\nnon-renormalizable connector operator suppressed by a large mass scale. In the\nlatter non-renormalizable scenario, the dominant creation of DM particles\ntypically occurs at the largest SM temperature attained during the radiation\nera (assuming a standard cosmological history), and for this reason it is\nreferred to as ultraviolet freeze-in. We show that non-renormalizable operators\ncan also contribute importantly to the DM density at lower temperatures down to\nbelow the mass of the DM particle. To do so, we compute the production,\nannihilation, and freeze-out of DM in a simple dark sector consisting of a\nmassive Dirac fermion DM candidate coupled to a massless Abelian vector boson\nwith the only connection to the SM through the fermionic Higgs portal operator.\nFor a broad range of parameters in the theory, the dark sector is populated by\nultraviolet freeze-in in the usual way, self-thermalizes to a dark temperature\nbelow that of the SM, and undergoes thermal freeze-out. We show that late\nresidual freeze-in reactions during the freeze-out process can further populate\nthe dark sector and increase the DM relic density beyond standard dark sector\nfreeze-out.", "category": "hep-ph" }, { "text": "Gravitational Lensing and Extra Dimensions: We study gravitational lensing and the bending of light in low energy scale\n(M_S) gravity theories with extra space-time dimensions n. We find that due to\nthe presence of spin-2 Kaluza-Klein states from compactification, a correction\nto the deflection angle with a strong quadratic dependence on the photon energy\nis introduced. No deviation from the Einstein General Relativity prediction for\nthe deflection angle for photons grazing the Sun in the visible band with 15%\naccuracy (90% c.l.) implies that the scale M_S has to be larger than\n1.4(2/(n-2))^{1/4} TeV and approximately 4 TeV for n=2. This lower bound is\ncomparable with that from collider physics constraints. Gravitational lensing\nexperiments with higher energy photons can provide stronger constraints.", "category": "hep-ph" }, { "text": "epsilon'/epsilon and Chiral Dynamics: The long-distance contributions to $K\\to 2\\pi$ amplitudes can be pinned down,\nusing well established Chiral Perturbation Theory techniques. The strong\nS--wave rescattering of the two final pions generates sizeable chiral loop\ncorrections, which have an important impact on the direct CP violation ratio\nepsilon'/epsilon. Including all large logarithmic corrections, both at short\nand long distances, the Standard Model Prediction for this observable is found\nto be Re(epsilon'/epsilon) = (1.7\\pm 0.9) 10^{-3}, in good agreement with the\nmost recent experimental measurements. A better estimate of the strange quark\nmass could reduce the theoretical uncertainty to 30%.", "category": "hep-ph" }, { "text": "$B{\\bar B}$ angular correlations at the LHC in parton Reggeization\n approach merged with higher-order matrix elements: We calculate the angular distribution spectra between beauty ($B$) and\nanti-beauty ($\\bar B$) mesons in proton-proton collisions in the leading order\napproximation of the parton Reggeization approach consistently merged with the\nnext-to-leading order corrections from the emission of additional hard gluon.\nTo describe b-quark hadronization we use the universal scale-depended\nparton-to-meson fragmentation functions extracted from the world $e^+e^-$\nannihilation data. We have obtained good agreement between our predictions and\ndata from the CMS Collaboration at the energy $\\sqrt{S}=7$ TeV for $B \\bar B$\nangular correlations within uncertainties and without free parameters.\nPredictions for analogous correlation observables at $\\sqrt{S}=13$ TeV are\nprovided.", "category": "hep-ph" }, { "text": "Coherent States in High-Energy Physics: The amplitude for emitting $n$ bosons factorizes into the product of $n$\nsingle-boson emission amplitudes, if the source is energetic and abelian. If it\nis energetic but {\\it non-abelian}, the amplitude is given by a sum of\nfactorized {\\it quasi-particle} amplitudes. A quasi-particle is made up of an\narbitrary number of bosons, but couples to the source like a single one.\nFactorization is related to coherence, and it allows computation of subleading\ncontributions not obtainable by usual means. Its importance is illustrated in\ntwo applications: to solve the baryon problem in large-$N_c$ QCD, and to obtain\na total cross section satisfying the Froissart bound.", "category": "hep-ph" }, { "text": "Nucleon-Nucleon Interaction and Isospin Violation: The application of the chiral effective theory to processes with two or more\nnucleons is discussed. We gain a qualitative understanding of the gross\nfeatures of nuclear physics and quantitative, testable postdictions and\npredictions involving photons and pions.", "category": "hep-ph" }, { "text": "Neutrino's Non-Standard Interactions; Another Eel under a Willow?: I report some progress that occurred since NO-VE08 in the field of\nnon-standard interactions (NSI) of neutrinos. After briefly reviewing\ntheoretical developments, I give a summary of the two works in which I was\ninvolved. Firstly, we have formulated a perturbative framework to illuminate\nthe global features of neutrino oscillations with NSI, aiming at exploring\nmethod for determination of the standard mixing and the NSI parameters. We have\nrecognized that the parameter degeneracy prevails with an extended form which\ninvolves the NSI elements. Furthermore, a completely new type of degeneracy is\nshown to exist. The nature of the former degeneracy is analyzed in detail in\nthe second work. The work is primarily devoted to analyze the problem of\ndiscriminating the two CP violation, one due to the lepton Kobayashi-Maskawa\nphase and the other by phases of the NSI elements. We have shown that the near\n(3000 km)-far (7000 km) two detector setting in neutrino factory does have the\ndiscrimination capability and is sensitivities to CP violation due to NSI to\n|epsilon_{e\\mu}| to \\simeq several x 10^{-4} in most of the region of \\delta\nand \\phi.", "category": "hep-ph" }, { "text": "More Energy, More Searches, but the pMSSM Lives On: We further examine the capability of the 7 and 8 TeV LHC to explore the\nparameter space of the p(henomenological)MSSM with neutralino LSPs. Here we\npresent an updated study employing all of the relevant ATLAS SUSY analyses, as\nwell as all relevant LHC non-MET searches, whose data were publically available\nas of mid-September 2012. We find that roughly 1/3 of our pMSSM model points\nare excluded at present with an important role being played by both the heavy\nflavor and multi-lepton searches, as well as those for heavy stable charged\nparticles. Nonetheless, we find that light gluinos, 1st/2nd generation squarks,\nand stop/sbottoms (\\lsim 400-700 GeV), as well as models with 1% fine-tuning or\nbetter, are still viable in the pMSSM. In addition, we see that increased\nluminosity at 8 TeV is unlikely to significantly improve the reach of the\n\"vanilla\" searches. The impact of these null searches on the SUSY sparticle\nspectrum is discussed in detail and the implications of these results for\nmodels with low fine-tuning, a future lepton collider and dark matter searches\nare examined.", "category": "hep-ph" }, { "text": "Quantum Mechanics with Neutral Kaons: We briefly illustrate a few tests of quantum mechanics which can be performed\nwith entangled neutral kaon pairs at a Phi-factory. This includes a\nquantitative formulation of Bohr's complementarity principle, the quantum\neraser phenomenon and various forms of Bell inequalities.", "category": "hep-ph" }, { "text": "Effect of CP violation in the singlet-doublet dark matter model: We revisit the singlet-doublet dark matter model with a special emphasis on\nthe effect of CP violation on the dark matter phenomenology. The CP violation\nin the dark sector induces a pseudoscalar interaction of a fermionic dark\nmatter candidate with the SM Higgs boson. The pseudoscalar interaction helps\nthe dark matter candidate evade the strong constraints from the dark matter\ndirect detection experiments. We show that the model can explain the measured\nvalue of the dark matter density even if dark matter direct detection\nexperiments do not observe any signal. We also show that the electron electric\ndipole moment is an important complement to the direct detection for testing\nthis model. Its value is smaller than the current upper bound but within the\nreach of future experiments.", "category": "hep-ph" }, { "text": "Measuring C-odd correlations at lepton-proton and photon-proton\n collisions: We consider the charge-odd correlations (COC) in cross sections of processes\nof production of charged particles. The cases of a muonic pair and pion systems\n$\\pi^{+}\\pi^{-},\\pi^{+}\\pi^{-}\\pi^{0}$ are considered in detail for\nelectron-proton or photon-proton collisions in the proton fragmentation region\nkinematics. COC arise from interference of amplitudes which describe the\ndifferent mechanisms of charged leptons (pions) creation. One of them\ncorresponds to production of particles in the charge-odd state (one virtual\nphoton or vector meson annihilation to this system of particles) and the other\ncorresponds to the charge-even state of produced particles (creation by two\nphotons). COC for muon-antimuon pair creation have a pure QED nature and can be\nconsidered as a normalization process. The processes with pion production are\nsensitive to some characteristics of proton wave functions and, besides, can be\nused for checking the anomalous and normal parts of the effective pionic\nlagrangian.\n Three electromagnetic currents operator matrix element can be measured in\nphoton-proton interactions with lepton pair production. For this aim a\ncharge-odd combination of cross sections can be constructed as a conversion of\nleptonic 3-rank tensor with hadronic ones. These experiments can be considered\nas an alternative to deep virtual Compton scattering.", "category": "hep-ph" }, { "text": "Cosmological Phase Transition of Spontaneous Confinement: The dynamics of a cosmological (de)confinement phase transition is studied in\nnearly conformally invariant field theories, where confinement is predominantly\nspontaneously generated and associated with a light \"dilaton\" field. We show\nhow the leading contribution to the transition rate can be computed within the\ndilaton effective theory. In the context of Composite Higgs theories, we\ndemonstrate that a simple scenario involving two renormalization-group fixed\npoints can make the transition proceed much more rapidly than in the minimal\nscenario, thereby avoiding excessive dilution of matter abundances generated\nbefore the transition. The implications for gravitational wave phenomenology\nare discussed. In general, we find that more (less) rapid phase transitions are\nassociated with weaker (stronger) gravitational wave signals. The various\npossible features of the strongly coupled composite Higgs phase transition\ndiscussed here can be concretely modeled at weak coupling within the AdS/CFT\ndual Randall-Sundrum extra-dimensional description, which offers important\ninsights into the nature of the transition and its theoretical control. These\naspects will be presented in a companion paper.", "category": "hep-ph" }, { "text": "Division algebraic symmetry breaking: Reframing certain well-known particle models in terms of normed division\nalgebras leads to two new results for BSM physics.\n (1) We identify a sequence of complex structures which induces a cascade of\nbreaking symmetries: Spin(10) $\\mapsto$ Pati-Salam $\\mapsto$ Left-Right\nsymmetric $\\mapsto$ Standard model + B-L (both pre- and post-Higgs-mechanism).\nThese complex structures derive from the octonions, then from the quaternions,\nthen from the complex numbers.\n (2) We provide, also for the first time we believe, an explicit demonstration\nof left-right symmetric Higgs representations stemming from quaternionic\ntriality, tri($\\mathbb{H}$). Upon the breaking of $su(2)_R$, our Higgs reduces\nto the familiar standard model Higgs.", "category": "hep-ph" }, { "text": "On the Character of Leading Asymmetry in the Hadroproduction of Charmed\n Mesons and Baryons: The character of asymmetry between the spectra of Lambda_c and antiLambda_c\nin the E781 experiment (FNAL) is discussed on the basis of the Quark Gluon\nString Model(QGSM). As it was shown in the description of the asymmetry between\nthe spectra of leading and nonleading charmed mesons measured in Sigma^--A\ninteractions at p_L= 340 GeV/c in the WA89 experiment in previous studies, the\nasymmetries between D^- and D^+ meson spectra and between D_s^- and D^+_s meson\nspectra can be fitted by QGSM curves with the same parameter of string\nfragmentation, a_1=10, as well as the asymmetry between the D-meson spectra in\npion-nuclear collisions in the E791 experiment. The forms of\nLambda_c/antiLambda_c asymmetry dependences measured in Sigma^-A and p-A\ncollisions at p_L= 600 GeV/c in the E781 experiment are different . It is shown\nin the framework of QGSM that they depend on whether the diquarks of beam and\ntarget particles took part in charmed baryon formation or not. The QGSM results\nare compared with the calculations carried out by the other authors.", "category": "hep-ph" }, { "text": "QCD corrections to longitudinal spin asymmetries in $W^\\pm$-boson\n production at RHIC: The polarized antiquark distributions in the proton can be measured by\nstudying spin asymmetries in vector boson production in longitudinally\npolarized proton-proton collisions. The STAR and PHENIX experiments at BNL RHIC\nhave reported first observations of single spin asymmetries in\n$W^\\pm$-production most recently. We compute the QCD corrections to single and\ndouble spin asymmetries, taking account of the leptonic decay of the $W^\\pm$\nboson and of restrictions on the kinematical acceptance of the detectors. The\nQCD corrections have only a small impact on the asymmetries, such that a\nreliable extraction of the polarized antiquark distributions can be envisaged\nonce more precise measurements are made.", "category": "hep-ph" }, { "text": "Pion structure function at small x from DIS data: Production of leading neutrons in DIS is usually considered as a tool to\nmeasure the pion structure function at small x accessible at HERA. The main\nobstacle is the lack of reliable evaluations of the absorption corrections,\nwhich significantly suppress the cross section. We performed a parameter free\ncalculation within the dipole approach and found the absorption corrections to\nbe nearly as strong, as for neutron production in pp collisions. We also\nincluded the significant contribution of the iso-vector Reggeons with natural\n(\\rho, a_2) and unnatural (a_1, \\rho-\\pi\\ cut) parity with parameters\nconstrained by phenomenology. With a certain modeling for the pion-to-proton\nratio of the structure functions we reached good agreement with data from the\nZEUS and H1 experiments, successfully reproducing the observed dependence on\nthe fractional neutron momentum z, the photon virtuality Q^2, and the\ntransverse momentum transfer q_T.", "category": "hep-ph" }, { "text": "SU(3) Chiral Dynamics with Coupled Channels: Eta and Kaon\n Photoproduction: We identify the leading s-wave amplitudes of the SU(3) chiral meson-baryon\nLagrangian with an effective coupled-channel potential which is iterated in a\nLippmann-Schwinger equation. The strangeness $S=-1$ resonance $\\Lambda(1405)$\nand the $S_{11}(1535)$ nucleon resonance emerge as quasi-bound states of\nanti-kaon/nucleon and kaon/$\\Sigma$-hyperon. Our approach to meson\nphotoproduction introduces no new parameters. By adjusting a few finite range\nparameters we are able to simultaneously describe a large amount of low energy\ndata. These include the cross sections of $K^-p$ elastic and inelastic\nscattering, the cross sections of eta meson and kaon photoproduction from\nnucleons as well as those of pion induced production of etas and kaons (16\ndifferent reaction channels altogether).", "category": "hep-ph" }, { "text": "Meson loop effect on high density chiral phase transition: We test the stability of the mean-field solution in the Nambu--Jona-Lasinio\nmodel. For stable solutions with respect to both the \\sigma and \\pi directions,\nwe investigate effects of the mesonic loop corrections of 1/N_c, which\ncorrespond to the next-to-leading order in the 1/N_c expansion, on the high\ndensity chiral phase transition. The corrections weaken the first order phase\ntransition and shift the critical chemical potential to a lower value. At\nN_c=3, however, instability of the mean field effective potential prevents us\nfrom determining the minimum of the corrected one.", "category": "hep-ph" }, { "text": "Study of $\u039b_b\\to \u039b(\u03c6,\u03b7^{(\\prime)})$ and $\u039b_b\\to\n \u039bK^+K^-$ decays: We study the charmless two-body $\\Lambda_b\\to \\Lambda (\\phi,\\eta^{(\\prime)})$\nand three-body $\\Lambda_b\\to \\Lambda K^+K^- $ decays. We obtain ${\\cal\nB}(\\Lambda_b\\to \\Lambda\\phi)=(3.53\\pm 0.24)\\times 10^{-6}$ to agree with the\nrecent LHCb measurement. However, we find that ${\\cal B}(\\Lambda_b\\to\n\\Lambda(\\phi\\to)K^+ K^-)=(1.71\\pm 0.12)\\times 10^{-6}$ is unable to explain the\nLHCb observation of ${\\cal B}(\\Lambda_b\\to\\Lambda K^+ K^-)=(15.9\\pm 1.2\\pm\n1.2\\pm 2.0)\\times 10^{-6}$, which implies the possibility for other\ncontributions, such as that from the resonant $\\Lambda_b\\to K^-\nN^*,\\,N^*\\to\\Lambda K^+$ decay with $N^*$ as a higher-wave baryon state. For\n$\\Lambda_b\\to \\Lambda \\eta^{(\\prime)}$, we show that ${\\cal B}(\\Lambda_b\\to\n\\Lambda\\eta,\\,\\Lambda\\eta^\\prime)= (1.47\\pm 0.35,1.83\\pm 0.58)\\times 10^{-6}$,\nwhich are consistent with the current data of $(9.3^{+7.3}_{-5.3},<3.1)\\times\n10^{-6}$, respectively. Our results also support the relation of ${\\cal\nB}(\\Lambda_b\\to \\Lambda\\eta) \\simeq {\\cal B}(\\Lambda_b\\to\\Lambda\\eta^\\prime)$,\ngiven by the previous study.", "category": "hep-ph" }, { "text": "Note on Custodial Symmetry in the Two-Higgs-Doublet Model: We present a simple and transparent method to study custodial symmetry in the\nTwo-Higgs-Doublet Model. The method allows to formulate the basis independent,\nsufficient and necessary, conditions for the custodial symmetry of the scalar\npotential. The relation between the custodial transformation and CP is\ndiscussed and clarified.", "category": "hep-ph" }, { "text": "A Remark on A Remark on Neutrino Oscillations Observed in KamLAND\n Experiment: It is shown that equal magnitudes of the transitions $\\bar \\nu_e \\to \\bar\n\\nu_{\\mu}$ and $\\bar \\nu_e \\to \\bar \\nu_{\\tau}$ in the disappearance of reactor\n$\\bar \\nu_e$ discovered in the KamLAND experiment just follows at\n$\\theta_{23}=\\pi/4$ and $\\theta_{13}=0$ from pure symmetry of $\\nu_{\\mu}$ and\n$\\nu_{\\tau}$ states relatively the mass states.", "category": "hep-ph" }, { "text": "Curvature-Restored Gauge Invariance and Ultraviolet Naturalness: It is shown that, $(a \\Lambda^2 + b |H|^2)R$ in a spacetime of curvature $R$\nis a natural ultraviolet $(U\\!V)$ completion of $(a \\Lambda^4 + b \\Lambda^2\n|H|^2)$ in the flat-spacetime Standard Model $(S\\!M)$ with Higgs field $H$,\n$U\\!V$ scale $\\Lambda$ and loop factors $a$, $b$. This curvature completion\nrests on the fact that a $\\Lambda$-mass gauge theory in flat spacetime turns,\non the cut-view $R = 4 \\Lambda^2$, into a massless gauge theory in curved\nspacetime. It provides a symmetry reason for curved spacetime, wherein gravity\nand matter are both low-energy effective phenomena. Gravity arises correctly if\nnew physics exists with at least 63 more bosons than fermions, with no need to\ninteract with the $S\\!M$ and with dark matter as a natural harbinger. It can\nsource various cosmological, astrophysical and collider phenomena depending on\nits spectrum and couplings to the $S\\!M$.", "category": "hep-ph" }, { "text": "Spontaneous Symmetry Breaking and Chiral Symmetry: In this introductory lecture, some basic features of the spontaneous symmetry\nbreaking are discussed. More specifically, $\\sigma $-model, non-linear\nrealization, and some examples of spontaneous symmetry breaking in the\nnon-relativistic system are discussed in details. The approach here is more\npedagogical than rigorous and the purpose is to get some simple explanation of\nsome useful topics in this rather wide area. .", "category": "hep-ph" }, { "text": "Deconstructing 5-D QED: We discuss periodic compactification and latticization of a 5-D U(1) theory\nwith a Dirac fermion, yielding a 1+3 effective theory. We address subtleties in\nthe lattice fermionic action,such as fermion doubling and the Wilson term. We\ncompute the Coleman-Weinberg potential for the Wilson line which is finite for\nN-branes >= 3, due to the Z_N symmetry, which replaces translations in the 5th\ndimension. This mode becomes a PNGB in the low energy 1+3 theory. We derive its\nanomalous coupling to the \"photon\" and its KK-modes.", "category": "hep-ph" }, { "text": "Role of beam polarization in the determination of $WW\u03b3$ and $WWZ$\n couplings from $e^+e^-\\to W^+W^-$: We evaluate the constraints on anomalous trilinear gauge-boson couplings that\ncan be obtained from the study of electron-positron annihilation into $W$ pairs\nat a facility with either the electron beam longitudinally polarized or both\nelectron and positron beams transversely polarized. The energy ranges\nconsidered in the analysis are the ones relevant to the next-linear collider\nand to LEP~200. We discuss the possibilities of a model independent analysis of\nthe general $CP$ conserving anomalous effective Lagrangian, as well as its\nrestriction to some specific models with reduced number of independent\ncouplings. The combination of observables with initial and final state\npolarizations allows to separately constrain the different couplings and to\nimprove the corresponding numerical bounds.", "category": "hep-ph" }, { "text": "Heavy quarks at RHIC and LHC within a partonic transport model: Production and space-time evolution of heavy quarks in central and\nnon-central heavy-ion collisions at RHIC and LHC are studied with the partonic\ntransport model Boltzmann Approach of MultiParton Scatterings (BAMPS). In\naddition to the initially created heavy quarks in hard parton scatterings\nduring nucleon-nucleon collisions, secondary heavy quark production in the\nquark-gluon plasma is investigated and the sensitivity on various parameters is\nestimated. In BAMPS heavy quarks scatter with particles of the medium via\nelastic collisions, whose cross section is calculated with the running coupling\nand a more precise implementation of Debye screening. In this framework, we\ncompute the elliptic flow and nuclear modification factor of heavy quarks and\ncompare it to the experimental data.", "category": "hep-ph" }, { "text": "CMB imprints of high scale non-thermal leptogenesis: We study the imprints of high scale non-thermal leptogenesis on cosmic\nmicrowave background (CMB) from the measurements of inflationary spectral index\n($n_s$) and tensor-to-scalar ratio ($r$), which otherwise is inaccessible to\nthe conventional laboratory experiments. We argue that non-thermal production\nof baryon (lepton) asymmetry from subsequent decays of inflaton to heavy\nright-handed neutrinos (RHN) and RHN to SM leptons is sensitive to the\nreheating dynamics in the early Universe after the end of inflation. Such\ndependence provides detectable imprints on the $n_s-r$ plane which is well\nconstrained by the Planck experiment. We investigate two separate cases, (I)\ninflaton decays to radiation dominantly and (II) inflaton decays to RHN\ndominantly which further decays to the SM particles to reheat the Universe\nadequately. Considering a class of $\\alpha-$ attractor inflation models, we\nobtain the allowed mass ranges for RHN for both cases and thereafter furnish\nthe estimates for $n_s$ and $r$. The prescription proposed here is general and\ncan be implemented in various kinds of single-field inflationary models given\nthe conditions for non-thermal leptogenesis are satisfied.", "category": "hep-ph" }, { "text": "Probing Charged Higgs Bosons in the 2-Higgs Doublet Model Type-II with\n Vector-Like Quarks: We study the phenomenology of charged Higgs bosons ($H^\\pm$) and Vector-Like\nQuarks (VLQs), denoted as $T$, the latter possessing a charge identical to the\ntop quark one, within the framework of the Two Higgs Doublet Model Type-II\n(2HDM-II). Upon examining two scenarios, one featuring a singlet $(T)$\n(2HDM-II+$(T)$) and another a doublet $(TB)$ (2HDM-II+$(TB)$), we discover that\nthe presence of VLQs has a significant effect on the (pseudo)scalar sector of\nthe 2HDM-II. In particular, this leads to a reduction in the strict constraint\non the mass of the charged Higgs boson, which is imposed by $B$-physics\nobservables, specifically $B\\to X_s\\gamma$. {The observed reduction stems from\nmodifications in the charged Higgs couplings to the Standard Model (SM) top and\nbottom quarks}. Notably, the degree of this reduction varies distinctly between\nthe singlet 2HDM+$(T)$ and doublet 2HDM+$(TB)$ scenarios. Additionally, our\ninvestigation extends to constraints imposed by the oblique parameters $S$ and\n$T$ on the VLQ mixing angles. Furthermore, to facilitate efficient exploration\nof the '2HDM-II+VLQ' parameter space, we present results on pair production of\nVLQs $T$ ($pp\\to T\\bar T$), followed by $T\\to H^\\pm b$ and $H^\\pm \\to tb$\ndecays, yielding a distinctive $2t4b$ final state. This investigation thus\nprovides valuable insights guiding the search for extended Higgs and quark\nsectors at the Large Hadron Collider (LHC) at CERN.", "category": "hep-ph" }, { "text": "Chiral Restoration in the Early Universe: Pion Halo in the Sky: < \\psibarpsi > vanishing above $T_c$ indicates chiral symmetry restoration at\nhigh $T$. But is it the old $T=0$ chiral symmetry that is `restored'? In this\ntalk, I report on the spacetime quantization of the BPFTW effective action for\nquarks in a hot environ. The fermion propagator is known to give a\npseudo-Lorentz invariant particle pole as well as new spacelike cuts. Our\nquantization shows that the spacelike cuts directly lead to a thermal vacuum\nthat is a generalized NJL state, with a curious $90^{o}$ phase. This $90^{o}$\nis responsible for < \\psibarpsi > vanishing at high $T$. The thermal vacuum is\ninvariant under a new chiral charge, but continues to break the old zero\ntemperature chirality. Our quantization suggests a new class of order\nparameters that probe the physics of these spacelike cuts. In usual scenario,\nthe pion dissociates in the early alphabet soup. With this new understanding of\nthe thermal vacuum, the pion remains a Nambu-Goldstone particle at high $T$,\nand will not dissociate. It propagates at the speed of light but with a halo.", "category": "hep-ph" }, { "text": "Studying the production mechanisms of light meson resonances in two-pion\n photoproduction: a Regge approach: A calculation of the angular moments of two-pion photoproduction is\npresented. The underlying theoretical model encodes the prominent $\\rho(770)$\nresonance and the expected leading background contribution coming from the Deck\nmechanism. The model contains a number of free parameters which are fit to\nexperimental data. A good description of the angular moments is obtained.", "category": "hep-ph" }, { "text": "Probing general $U(1)'$ models with non-universal lepton charges at\n FASER/FASER2, COHERENT and long-baseline oscillation experiments: The general anomaly-free $U(1)'$ models allow non-universal lepton charges.\nWe explore the sensitivities of FASER/FASER2, COHERENT and DUNE/T2HK precision\nexperiments to the new gauge boson $Z'$ and the new CP-even scalar $\\phi$. With\nnon-universal lepton charges, distinctive reaches at FASER/FASER2 emerge in the\nregime of low $m_{Z'}$ and small gauge coupling $g_{BL}$ for different $U(1)'$\ncharge setups. The COHERENT experiment and the future long-baseline experiments\nDUNE/T2HK also provide complementary probes to the available parameter space.\nFor $m_\\phi < 2m_{Z'}$, the search for the scalar $\\phi$ at FASER/FASER2 is\nsensitive to the mixing angle between the scalar singlet and the SM Higgs. In\nthe case of $m_\\phi > 2m_{Z'}$, the kinematically allowed decay $\\phi\\to Z' Z'$\nchanges the lifetime and decay rates of the scalar $\\phi$. The sensitivity\nreach highly depends on the $Z'$ mass and the gauge coupling $g_{BL}$.", "category": "hep-ph" }, { "text": "Theoretical Expectations for the Muon's Electric Dipole Moment: We examine the muon's electric dipole moment $\\dmu$ from a variety of\ntheoretical perspectives. We point out that the reported deviation in the\nmuon's g-2 can be due partially or even entirely to a new physics contribution\nto the muon's {\\em electric} dipole moment. In fact, the recent g-2 measurement\nprovides the most stringent bound on $\\dmu$ to date. This ambiguity could be\ndefinitively resolved by the dedicated search for $\\dmu$ recently proposed. We\nthen consider both model-independent and supersymmetric frameworks. Under the\nassumptions of scalar degeneracy, proportionality, and flavor conservation, the\ntheoretical expectations for $\\dmu$ in supersymmetry fall just below the\nproposed sensitivity. However, non-degeneracy can give an order of magnitude\nenhancement, and lepton flavor violation can lead to $\\dmu$ of order $10^{-22}$\ne cm, two orders of magnitude above the sensitivity of the $\\dmu$ experiment.\nWe present compact expressions for leptonic dipole moments and lepton flavor\nviolating amplitudes. We also derive new limits on the amount of flavor\nviolation allowed and demonstrate that approximations previously used to obtain\nsuch limits are highly inaccurate in much of parameter space.", "category": "hep-ph" }, { "text": "Theory of Small $x$ Deep Inelastic Scattering NLO Evaluations, and low\n $Q^2$ Analysis: We calculate structure functions at small $x$ both under the assumption of a\nhard singularity (a power behaviour $x^{-\\lambda}, \\lambda$ positive, for\n$x\\rightarrow 0$) or that of a soft-Pomeron dominated behaviour, also called\ndouble scaling limit, for the singlet component. A full next to leading order\n(NLO) analysis is carried for the functions $F_2, F_{\\rm Glue}$ and the\nlongitudinal one $F_L$ in $ep$ scattering, and for $x F_3$ in neutrino\nscattering. The results of the calculations are compared with data (HERA) in\nthe range $x\\leq 0.032, 10 gev^2\\leq Q^2\\leq 1 500 gev^2$. We get reasonable\nfits, with a chi-squared/d.o.f.$\\sim 2$, for both assumptions, but none of them\ngives a fully satisfactory description. The results improve substantially if\ncombining a soft and a hard component; in this case it is even possible to\nextend the analysis, phenomenologically, to small values of $Q^2$, $0.31\ngev^2\\leq Q^2\\leq 8.5 gev^2$, and in the $x$ range $6\\times10^{-6}\\lsim x \\lsim\n0.04$, with the same hard plus soft Pomeron hypothesis by assuming a saturating\nexpression for the strong coupling,\n$\\tilde{\\alpha}_s(Q^2)=4\\pi/\\beta_0\\log[(Q^2+\\Lambda_{eff}^2)/\\Lambda_{eff}^2]$\nThe description for low $Q^2$ implies self-consistent values for the parameters\nin the exponents of $x$. One gets, for the Regge intercepts,\n$\\alpha_{\\rho}(0)=0.48$ and $\\alpha_P(0)=1.470$ [$\\lambda=0.470$], in uncanny\nagreement with other determinations of these parameters, in particular the\nresults of the large $Q^2$ fits. The fit to is so good that we may look (at\nlarge $Q^2$) for signals of a \"triple Pomeron\" vertex; some evidence is found.", "category": "hep-ph" }, { "text": "Supersymmetric SU(3) X U(1) Gauge Model: Higgs Structure at the\n Electroweak Scale: We consider a supersymmetric version of the recently proposed SU(3) X U(1)\nextended gauge model. We show that it is possible to have only two Higgs\ndoublets at the SU(2) X U(1) energy scale but they are not those of the minimal\nsupersymmetric standard model. In particular, the upper bound on the lightest\nscalar boson of this model is $4 M_Z \\sin \\theta_W$ at tree level and goes up\nto 189 GeV after radiative corrections.", "category": "hep-ph" }, { "text": "Tests of Lorentz symmetry: A number of approaches to fundamental physics can lead to the violation of\nLorentz and CPT symmetry. This talk discusses the low-energy phenomenology\nassociated with such effects and reviews various sample experiments within this\ncontext.", "category": "hep-ph" }, { "text": "Properties of excited charmed-bottom mesons: We calculate the spectrum of $B_c$ mesons using a non-relativistic quark\npotential model. Using the calculated wave functions, we compute the radiative\nwidths of $B_c$ excited states. The strong decay widths are calculated in a\nmodified $^3P_0$ model, assuming harmonic oscillator wave functions. The\nhadronic transition rates of $B_c$ mesons are calculated using the Kuang-Yan\napproach. These results are used to determine branching ratios of possible\ndecay channels of several $B_c$ excited states. Calculated branching ratios are\nthen combined with production cross section of $B_c$ states at the LHC to\nsuggest strategies to find missing excited states of $B_c$ mesons.", "category": "hep-ph" }, { "text": "Radiative corrections to $h^0\\to WW^*/ZZ^*\\to 4$\\,leptons in the MSSM: The electroweak $\\mc O(\\alpha)$ radiative corrections to the decay of the\nlightest MSSM Higgs boson to four leptons are presented, improved by the\ntwo-loop corrections provided by the program package FeynHiggs. We also analyze\nthe results in the decoupling limit and investigate the numeric impact of\ncontributions from the genuine supersymmetric particle spectrum.", "category": "hep-ph" }, { "text": "Thermodynamic instabilities in dynamical quark models with complex\n conjugate mass poles: We show that the CJT thermodynamic potential of dynamical quark models with a\nquark propagator represented by complex conjugate mass poles inevitably\nexhibits thermodynamic instabilities. We find that the minimal coupling of the\nquark sector to a Polyakov loop potential can strongly suppress but not\ncompletely remove such instabilities. This general effect is explicitly\ndemonstrated in the framework of a covariant, chirally symmetric, effective\nquark model.", "category": "hep-ph" }, { "text": "The LHCb pentaquark as a $\\bar{D}^*\u03a3_c-\\bar{D}^*\u03a3_c^*$\n molecular state: We perform a theoretical analysis of the $\\Lambda_b \\to J/\\psi K^- p$\nreaction from where a recent LHCb experiment extracts a $\\Lambda(1405)$\ncontribution in the $K^- p$ spectrum close to threshold and two baryon states\nof hidden charm in the $J/\\psi\\,p$ spectrum. We recall that baryon states of\nthis type have been theoretically predicted matching the mass, width and $J^P$\nof the experiment, concretely some states built up from the $J/\\psi\\, N$, $\\bar\nD^* \\Lambda_c$, $\\bar D^* \\Sigma_c$, $\\bar D \\Sigma^*_c$ and $\\bar D^*\n\\Sigma^*_c$ coupled channels. We assume that the observed narrow state around\n4450 MeV has this nature and we are able to describe simultaneously the shapes\nand relative strength of the the $K^- p$ mass distribution close to threshold\nand the peak of the $J/\\psi\\,p$ distribution, with values of the $J/\\psi\\, p$\ncoupling to the resonance in line with the theoretical ones. The non trivial\nmatching of many properties gives support to a $J^P=3/2^-$ assignment to this\nstate and to its nature as a molecular state mostly made of $\\bar D^* \\Sigma_c$\nand $\\bar D^* \\Sigma^*_c$.", "category": "hep-ph" }, { "text": "Next-to-Leading-Order Corrections to the Production of Heavy-Flavour\n Jets in e+e- Collisions: In this thesis we describe the calculation of the process e+ e- --> Z/gamma\n-> Q Qbar + X, where Q is a heavy quark, X is anything else at order alpha_s^2.", "category": "hep-ph" }, { "text": "Sun Heated MeV-scale Dark Matter and the XENON1T Electron Recoil Excess: The XENON1T collaboration reported an excess of the low-energy electron\nrecoil events between 1 and 7 keV. We explore the possibility to explain such\nan anomaly by the MeV-scale dark matter (DM) heated by the interior of the Sun\ndue to the same DM-electron interaction as in the detector. The kinetic\nenergies of heated DM particles can reach a few keV, and can potentially\naccount for the excess signals detected by XENON1T. We study different form\nfactors of the DM-electron interactions, $F(q)\\propto q^i$ with $i=0,1,2$ and\n$q$ being the momentum exchange, and find that for all these cases the\ninclusion of the Sun-heated DM component improves the fit to the XENON1T data.\nThe inferred DM-electron scattering cross section (at $q=\\alpha m_e$ where\n$\\alpha$ is the fine structure constant and $m_e$ is electron mass) is from\n$\\sim 10^{-38}$~cm$^2$ (for $i=0$) to $\\sim 10^{-42}$~cm$^2$ (for $i=2$). We\nalso derive constraints on the DM-electron cross sections for different form\nfactors, which are stronger than previous results with similar assumptions. We\nemphasize that the Sun-heated DM scenario relies on the minimum assumption on\nDM models, which serves as a general explanation of the XENON1T anomaly via\nDM-electron interaction. The spectrum of the Sun-heated DM is typically soft\ncomparing to other boosted DM, so the small recoil events are expected to be\nabundant in this scenario. More sensitive direct detection experiments with\nlower thresholds can possibly distinguish this scenario with other boosted DM\nmodels or solar axion models.", "category": "hep-ph" }, { "text": "Fast neutrino flavor conversions near the supernova core with realistic\n flavor-dependent angular distributions: It has been recently pointed out that neutrino fluxes from a supernova can\nshow substantial flavor conversions almost immediately above the core. Using\nlinear stability analyses and numerical solutions of the fully nonlinear\nequations of motion, we perform a detailed study of these fast conversions,\nfocussing on the region just above the supernova core. We carefully specify the\ninstabilities for evolution in space or time, andfind that neutrinos travelling\ntowards the core make fast conversions more generic, i.e., possible for a wider\nrange of flux ratios and angular asymmetries that produce a crossing between\nthe zenith-angle spectra of $\\nu_e$ and ${\\bar\\nu_e}$. Using fluxes and angular\ndistributions predicted by supernova simulations, we find that fast conversions\ncan occur within tens of nanoseconds, only a few meters away from the putative\nneutrinospheres. If these fast flavor conversions indeed take place, they would\nhave important implications for the supernova explosion mechanism and\nnucleosynthesis.", "category": "hep-ph" }, { "text": "Supernova Bounds on Neutrino Properties: a mini-review: This talk summarizes our recent work which studied the impact of resonant\nneutrino conversion induced by some non-standard neutrino properties beyond\nmass and mixing, such as neutrino magnetic moment, lepton-flavor\nnon-universality as well as flavor changing neutral current interactions in\nSUSY models with broken R parity, on supernova physics.", "category": "hep-ph" }, { "text": "g_\u03bc- 2 in Supersymmetry: The 2.6 sigma deviation in the muon's anomalous magnetic moment has strong\nimplications for supersymmetry. In the most model-independent analysis to date,\nwe consider gaugino masses with arbitrary magnitude and phase, and sleptons\nwith arbitrary masses and left-right mixings. For tan(beta)=50, we find that 1\nsigma agreement requires at least one charged superpartner with mass below 570\nGeV; at 2 sigma, this upper bound shifts to 850 GeV. The deviation is\nremarkably consistent with all constraints from colliders, dark matter, and b\n-> s gamma in supergravity models, but disfavors the characteristic gaugino\nmass relations of anomaly-mediation.", "category": "hep-ph" }, { "text": "Polyakov Loop at Finite Temperature in Chiral Quark Models: At finite temperature, chiral quark models do not incorporate large gauge\ninvariance which implies genuinely non-perturbative finite temperature gluonic\ndegrees of freedom. Motivated by this observation, we describe how the coupling\nof the Polyakov loop as an independent degree of freedom to quarks not only\naccounts for large gauge invariance, but also allows to establish in a\ndynamical way the interaction between composite hadronic states such as\nGoldstone bosons to finite temperature non-perturbative gluons in a medium\nwhich can undergo a confinement-deconfinement phase transition.", "category": "hep-ph" }, { "text": "Systematics of parton-medium interaction from RHIC to LHC: Despite a wealth of experimental data for high-P_T processes in heavy-ion\ncollisions, discriminating between different models of hard parton-medium\ninteractions has been difficult. A key reason is that the pQCD parton spectrum\nat RHIC is falling so steeply that distinguishing even a moderate shift in\nparton energy from complete parton absorption is essentially impossible. In\nessence, energy loss models are effectively only probed in the vicinity of zero\nenergy loss and, as a result, at RHIC energies only the pathlength dependence\nof energy loss offers some discriminating power. At LHC however, this is no\nlonger the case: Due to the much flatter shape of the parton p_T spectra\noriginating from 2.76 AGeV collisions, the available data probe much deeper\ninto the model dynamics. A simultaneous fit of the nuclear suppression at both\nRHIC and LHC energies thus has great potential for discriminating between\nvarious models that yield equally good descriptions of RHIC data alone.", "category": "hep-ph" }, { "text": "Matching the Low and High Energy Determinations of $\u03b1_s(M_z)$ in\n the MSSM: Recent calculations of supersymmetric corrections to the conflicting ratios\n$R_b$ and $R_c$ have shown that an alleged discrepancy between the SM\npredictions of these observables and the corresponding experimental values can\nbe cured in the MSSM within a certain region of the parameter space. Here we\nshow that, in this very same region, also a well-known discrepancy between the\nlow and high energy determinations of $\\alpha_s(M_Z)$ can be disposed of.\nSpecifically, we find that the lineshape determination of the strong coupling\nconstant, which in the SM points towards the large central value $\\alpha_s(M_Z)\n\\stackrel{\\scriptstyle >}{{ }_{\\sim}} 0.125$, can be matched up with the value\nsuggested by the wealth of low-energy data, namely $\\alpha_s(M_Z) \\simeq 0.11$,\nwhich is smaller and more in line with the traditional QCD expectations at low\nenergy. Our approach differs from previous analyses in that we argue that the\ndesired matching could originate to a large extent from a purely electroweak\nsupersymmetric quantum effect.", "category": "hep-ph" }, { "text": "Model-Independent Global Constraints on New Physics: Using effective-lagrangian techniques we perform a systematic survey of the\nlowest-dimension effective interactions through which heavy physics might\nmanifest itself in present experiments. We do not restrict ourselves to special\nclasses of effective interactions (such as `oblique' corrections). We compute\nthe effects of these operators on all currently well-measured electroweak\nobservables, both at low energies and at the $Z$ resonance, and perform a\nglobal fit to their coefficients. Despite the fact that a great many operators\narise in our survey, we find that most are quite strongly bounded by the\ncurrent data. We use our survey to systematically identify those effective\ninteractions which are {\\it not} well-bounded by the data -- these could very\nwell include large new-physics contributions. Our results may also be used to\nefficiently confront specific models for new physics with the data, as we\nillustrate with an example.", "category": "hep-ph" }, { "text": "Meson-like Baryons and the Spin-Orbit Puzzle: I describe a special class of meson-like \\Lambda_Q excited states and present\nevidence supporting the similarity of their spin-independent spectra to those\nof mesons. I then examine spin-dependent forces in these baryons, showing that\npredicted effects of spin-orbit forces are small for them for the same reason\nthey are small for the analogous mesons: a fortuitous cancellation between\nlarge spin-orbit forces due to one-gluon-exchange and equally large inverted\nspin-orbit forces due to Thomas precession in the confining potential. In\naddition to eliminating the baryon spin-orbit puzzle in these states, this\nsolution provides a new perspective on spin-orbit forces in all baryons.", "category": "hep-ph" }, { "text": "The mass spectrum and strong decays of isoscalar tensor mesons: In this work, we present a systematic study of the observed isoscalar tensor\n$f_2$ states. With the detailed analysis of the mass spectrum and calculation\nof the $f_2$ two-body strong decays, we extract information of their underly\nstructures, and try to categorize them into the conventional tensor meson\nfamily ($n^{3}P_{2}$ $(n=1,2,3,4)$ and $m^{3}F_{2}$ ($m=1,2$)). We also give\npredictions for other decay modes of these tensor mesons, which are useful for\nfurther experimental investigations.", "category": "hep-ph" }, { "text": "Bayesian fit analysis to full distribution data of $\\bar B \\to D^{(*)}\n \\ell\\bar\u03bd$: $|V_{cb}|$ determination and New Physics constraints: We investigate the semi-leptonic decays of $\\bar B \\to D^{(*)} \\ell\\bar\\nu$\nin terms of the Heavy-Quark-Effective-Theory (HQET) parameterization for the\nform factors, which is described with the heavy quark expansion up to $\\mathcal\nO(1/m_c^2)$ beyond the simple approximation considered in the original CLN\nparameterization. An analysis with this setup was first given in the\nliterature, and then we extend it to the comprehensive analyses including (i)\nsimultaneous fit of $|V_{cb}|$ and the HQET parameters to available\nexperimental full distribution data and theory constraints, and (ii) New\nPhysics (NP) contributions of the $V_2$ and $T$ types to the decay\ndistributions and rates. For this purpose, we perform Bayesian fit analyses by\nusing Stan program, a state-of-the-art public platform for statistical\ncomputation. Then, we show that our $|V_{cb}|$ fit results for the SM scenarios\nare close to the PDG combined average from the exclusive mode, and indicate\nsignificance of the angular distribution data. In turn, for the $\\text{SM} +\n\\text{NP}$ scenarios, our fit analyses find that non-zero NP contribution is\nfavored at the best fit point for both $\\text{SM} + V_2$ and $\\text{SM} + T$\ndepending on the HQET parameterization model. A key feature is then realized in\nthe $\\bar B \\to D^{(*)} \\tau\\bar\\nu$ observables. Our fit result of the HQET\nparameters in the $\\text{SM} (+T)$ produces a consistent value for $R_D$ while\nsmaller for $R_{D^*}$, compared with the previous SM prediction in the HFLAV\nreport. On the other hand, $\\text{SM}+V_2$ points to smaller and larger values\nfor $R_D$ and $R_{D^*}$ than the SM predictions. In particular, the $R_{D^*}$\ndeviation from the experimental measurement becomes smaller, which could be\ninteresting for future improvement on measurements at the Belle II experiment.", "category": "hep-ph" }, { "text": "The electromagnetic Sigma-to-Lambda hyperon transition form factors at\n low energies: Using dispersion theory the low-energy electromagnetic form factors for the\ntransition of a Sigma to a Lambda hyperon are related to the pion vector form\nfactor. The additionally required input, i.e. the two-pion--Sigma--Lambda\namplitudes are determined from relativistic next-to-leading-order (NLO) baryon\nchiral perturbation theory including the baryons from the octet and optionally\nfrom the decuplet. Pion rescattering is again taken into account by dispersion\ntheory. It turns out that the inclusion of decuplet baryons is not an option\nbut a necessity to obtain reasonable results. The electric transition form\nfactor remains very small in the whole low-energy region. The magnetic\ntransition form factor depends strongly on one not very well determined\nlow-energy constant of the NLO Lagrangian. One obtains reasonable predictive\npower if this low-energy constant is determined from a measurement of the\nmagnetic transition radius. Such a measurement can be performed at the future\nFacility for Antiproton and Ion Research (FAIR).", "category": "hep-ph" }, { "text": "Search for New Physics in Rare Top Decays: Top physics provides a fertile ground for new-physics searches. At present,\nmost top observables appear to be in good agreement with the respective\nStandard Model predictions. However, in the case of decay modes that are\nsuppressed in the Standard Model, new-physics contributions of comparable\nmagnitude may exist and yet go unnoticed because their impact on the total\ndecay width is small. Hence it is interesting to probe rare top decays. This\nanalysis focuses on the decay $t \\to b \\bar b c$. Useful observables are\nidentified and prospects for measuring new-physics parameters are examined.", "category": "hep-ph" }, { "text": "Pair Production of Doubly-Charged Scalars: Neutrino Mass Constraints and\n Signals at the LHC: We study the pair production of doubly charged Higgs bosons at the Large\nHadron Collider (LHC), assuming the doubly charged Higgs to be part of an\nSU(2)_L triplet which generates Majorana masses for left-handed neutrinos. Such\npair-production has the advantage that it is not constrained by the triplet\nvacuum expectation value, which tends to make the single production rate rather\nsmall. We point out that, in addition to the Drell-Yan (DY) production\nmechanism, two-photon processes also contribute to H++H++ production at a level\ncomparable to the QCD corrections to the DY channel. Decays of the doubly\ncharged Higgs into both the l+l+ and W+W+ modes are studied in detail to\noptimize the signal observation over the backgrounds. Doubly charged scalars\nshould be observable at the LHC with 300 fb^-1 integrated luminosity in the ll\nchannel upto the mass range of 1 TeV even with a branching fraction of about 60\n%, and in the WW channel upto a mass of 700 GeV. Such a doubly charged Higgs,\nif it is a member of a triplet generating neutrino masses,cannot be long-lived\non the scale of collider detectors although it might lead to a displaced\nsecondary vertex during its decay if it is lighter than about 250 GeV.", "category": "hep-ph" }, { "text": "Gluon Radiation in $t\\bar t$ Production and Decay at the LHC: Understanding the pattern of gluon radiation in $t \\bar t$ production and\ndecay processes is important for making an accurate determination of the top\nmass from the momenta of its decay products. The larger energy of the LHC $pp$\ncollider boosts the top cross section by a factor of 100 compared to that at\nthe Tevatron, but it also increases the amount of additional gluon radiation.\nWe calculate the cross section for gluon radiation in top production and decay\nat the LHC. The distributions of this radiation are presented and the exact\nmatrix-element results are compared with results from the HERWIG parton-shower\nMonte Carlo.", "category": "hep-ph" }, { "text": "A bound on Universal Extra Dimension Models from up to 2fb^{-1} of LHC\n Data at 7TeV: The recent up to 2fb^{-1} of data from the ATLAS and CMS experiments at the\nCERN Large Hadron Collider at 7TeV put an upper bound on the production cross\nsection of a Higgs-like particle. We translate the results of the H -> WW -> l\nnu l nu and H -> gamma gamma as well as the combined analysis by the ATLAS and\nCMS into an allowed region for the Kaluza-Klein (KK) mass M_{KK} and the Higgs\nmass $M_H$ for all the known Universal Extra Dimension (UED) models in five and\nsix dimensions. Our bound is insensitive to the detailed KK mass splitting and\nmixing and hence complementary to all other known signatures.", "category": "hep-ph" }, { "text": "The Top Quark and other Fermion Masses: Recent developments on approaches to the quark lepton mass problem are\nreviewed. In particular we discuss dynamical calculations of the top quark mass\nat (a) the infrared quasifixed point of the Minimal Supersymmetric Standard\nModel renormalisation group equations, and (b) a strongly first order critical\npoint of the Standard Model effective potential. The phenomenology of symmetric\nmass matrix ans\\\"{a}tze with texture zeros at the unification scale is also\nconsidered. The underlying chiral symmetry presumed responsible for the fermion\nmass hierarchy is discussed, with particular reference to superstring based\nmodels.", "category": "hep-ph" }, { "text": "Vector-like Quarks: In this talk we emphasise the importance of vector-like quarks (VLQs) and\ntheir potential to solve some of the open questions of the Standard Model.\nThese are, in some sense minimal extensions of the Standard Model, that can be\nprobed in the next round of experiments. We also make an analogy between\nvector-like quarks(VLQs) and right-handed neutrinos, emphasising that in both\ncases some of the flavour dogmas of the SM are violated in a controlled way.", "category": "hep-ph" }, { "text": "Matter-antimatter origin of cosmic magnetism: We explore the hypothesis that the abundant presence of relativistic\nantimatter (positrons) in the primordial universe is the source of the\nintergalactic magnetic fields we observe in the universe today. We evaluate\nboth Landau diamagnetic and magnetic dipole moment paramagnetic properties of\nthe very dense primordial electron-positron $e^{+}e^{-}$-plasma, and obtain in\nquantitative terms the relatively small magnitude of the $e^{+}e^{-}$ magnetic\nmoment polarization asymmetry required to produce a consistent\nself-magnetization in the universe.", "category": "hep-ph" }, { "text": "B^0_{d,s} - \\bar{B}^0_{d,s} mixing in the model III 2HDM: In the model III 2HDM there are new CP violating phases which would affect\nthe $B_{d,s}^0 - \\bar{B}_{d,s}^0$ mixing. In this paper, we calculate the new\nphysics contributions to the neutral B meson mass splitting $\\Delta M_{B_q}$\n(q=d, s) at the next-to-leading order (NLO) level. Using the high accuracy data\nand other relevant data, we draw the constraints on the parameter space of the\nmodel III 2HDM. Moreover, we calculate the new physics corrections to the ratio\n$q/p$. It is found that the phase of $(q/p)_n$ for $B_d$ which is due to the\nnew contributions is very small and consequently in agreement with the\nmeasurements of the time dependent CP asymmetry $S_{J/\\psi K}$ in $B\\to J/\\psi\nK_S$. On the contrary, the phase of $(q/p)_n$ for $B_s$ is large enough to give\nsignificant effects on CP violation in the neutral $B_s$ system.", "category": "hep-ph" }, { "text": "Phenomenology of light remnant doubly charged Higgs fields in the\n supersymmetric left-right model: It has recently shown that in supersymmetric left-right models with automatic\nR-parity conservation, the theory below the $W_R$ scale is given by MSSM with\nmassive neutrinos and a pair of doubly charged superfields with masses in the\n100 GeV range (with or without an extra pair of heavy Higgs doublets (M \\geq 10\nTeV) depending on the model). In this paper we study the unification prospects\nfor such theories and their phenomenological implications for collider\nexperiments. We study two versions of the theory, one with supersymmetry\nbreaking transmitted via the gauge and another where the same occurs via\ngravitational forces. We point out that looking at multi $\\tau$ final states\ncan considerably constrain the parameter space of the model.", "category": "hep-ph" }, { "text": "Jet angularities in photoproduction at the Electron-Ion Collider: We consider the one-parameter family of jet substructure observables known as\nangularities using the specific case of inclusive jets arising from\nphotoproduction events at an Electron-Ion Collider (EIC). We perform numerical\ncalculations at next-to-leading logarithmic accuracy within perturbative QCD\nand compare our results to PYTHIA 6 predictions. Overall, we find good\nagreement and conclude that jet substructure observables are feasible at the\nEIC despite the relatively low jet transverse momentum and particle\nmultiplicities. We investigate the size of subleading power corrections\nrelevant at low energies within the Monte Carlo setup. In order to establish\nthe validity of the Monte Carlo tune, we also perform comparisons to jet shape\ndata at HERA. We further discuss detector requirements necessary for angularity\nmeasurements at an EIC, focusing on hadron calorimeter energy and spatial\nresolutions. Possible applications of precision jet substructure measurements\nat the EIC include the tuning of Monte Carlo event generators, the extraction\nof nonperturbative parameters and studies of cold nuclear matter effects.", "category": "hep-ph" }, { "text": "What the Tevatron Found?: The CDF collaboration has reported a 4.1\\sigma\\ excess in their lepton,\nmissing energy, and dijets channel. This excess, which takes the form of an\napproximately Gaussian peak centered at a dijet invariant mass of 147 GeV, has\nprovoked a great deal of experimental and theoretical interest. Although the\nD\\O\\ collaboration has reported that they do not observe a signal consistent\nwith CDF, there is currently no widely accepted explanation for the discrepancy\nbetween these two experiments. A resolution of this issue is of great\nimportance---not least because it may teach us lessons relevant for future\nsearches at the LHC---and it will clearly require additional information. In\nthis paper, we consider the ability of the Tevatron and LHC detectors to\nobserve evidence associated with the CDF excess in a variety of channels. We\nalso discuss the ability of selected kinematic distributions to distinguish\nbetween Standard Model explanations of the observed excess and various new\nphysics scenarios.", "category": "hep-ph" }, { "text": "Probing top-partners in Higgs + jets: Fermionic top-partners arise in models such as Composite Higgs and Little\nHiggs. They modify Higgs properties, in particular how the Higgs couples to top\nquarks. Alas, there is a low-energy cancellation acting in the coupling of the\nHiggs boson to gluons and photons. As a result of this cancellation, no\ninformation about the spectrum and couplings of the top-partners can be\nobtained in gluon fusion to Higgs, just the overall new physics scale. In this\npaper we show that this is not the case when hard radiation is taken into\naccount. Indeed, differential distributions in Higgs plus jets are sensitive to\nthe top-partner mass and coupling to the Higgs. We exploit the transverse\nmomentum distribution of the hard jet to obtain limits on the top-partners in\nthe 14 TeV LHC run, finding that 300 ifb of data of 14 TeV LHC are sufficient\nto rule out top-sector mixing angles $\\sin^2 (\\theta_R)$ > 0.05 for\ntop-partners with masses from 300 GeV to above 2 TeV.", "category": "hep-ph" }, { "text": "Vortex Production in a First Order Phase-Transition at Finite\n Temperature: We simulate the production of vortices in a first order phase transition at\nfinite temperature. The transition is carried out by randomly nucleating\ncritical bubbles and the effects of thermal fluctuations (which could be\nrelevant for vortex production) are represented by randomly nucleating\nsubcritical bubbles. Our results show that the presence of subcritical bubbles\nsuppresses vortices with clear and prominent profiles, though net number of\nvortices is consistent with theoretical estimates. We also determine the\ntypical speed of vortices arising due to randomness associated with the phase\ntransition to be about 0.5.", "category": "hep-ph" }, { "text": "Confinement and complex singularities in QED3: The standard approximations of the Dyson--Schwinger equation lead to complex\nsingularities of the fermion propagator. In three-dimensional QED one can show\nthat this phenomenon might be related to confinement: a confining potential\nleads to mass-like singularities at complex momenta, and thus to the absence of\na mass singularity on the real timelike axis. The correct treatment of the\nvacuum polarization is essential for the confining nature of QED3.", "category": "hep-ph" }, { "text": "Radiative jet energy loss in a three-dimensional hydrodynamical medium\n and high $p_T$ azimuthal asymmetry of $\u03c0_0$ suppression at mid and forward\n rapidity at RHIC: The nuclear modification factor $R_{AA}$ for $\\pi_0$ production in Au+Au\ncollisions at $\\sqrt{s}=200$ AGeV is calculated, and studied at high transverse\nmomenta $p_T$. The soft thermalized nuclear medium is described within the\nframework of relativistic ideal three-dimensional hydrodynamics. The energy\nloss of partonic jets is evaluated in the context of gluon bremsstrahlung in\nthe thermalized partonic matter. We provide a systematic analysis of the\nazimuthal asymmetry of $\\pi_0$ suppression at high $p_T$ in central and\nnon-central collisions, at mid and forward rapidity. The determination of\n$R_{AA}$ as a function of $p_T$, at different azimuthal angles, and different\nrapidities makes for a stringent test of our theoretical understanding of jet\nenergy loss over a variety of in-medium path lengths, temperatures and initial\npartonic jet energies. This lays the groundwork for a precise tomography of the\nnuclear medium.", "category": "hep-ph" }, { "text": "Intrinsic three-body nuclear interaction from a constituent quark model: We study the short distance part of the intrinsic three-nucleon interaction\nin a constituent quark model with color-spin interaction. For that purpose we\nfirst calculate the transformation coefficient between the tribaryon\nconfiguration and their corresponding three baryon basis. Using a formula for\nthe intrinsic three-body interaction in terms of a tribaryon configuration, we\nfind that after subtracting the corresponding two-baryon contributions, the\nintrinsic three-body interaction vanishes in flavor SU(3) symmetric limit for\nall quantum numbers for the three nucleon states. We further find that the\nintrinsic three-body interaction also vanishes for flavor-spin type of quark\ninteraction.", "category": "hep-ph" }, { "text": "Direct detection of freeze-in inelastic dark matter: We show that the current sensitivities of direct detection experiments have\nalready reached the interesting parameter space of freeze-in dark matter models\nif the dark sector is in the inelastic dark matter framework and the excited\ndark matter state is cosmologically stable. Using results recently presented by\nthe XENON1T experiment, we present constraints on these models. We also show\nthat these models can explain the reported excess in the electron recoil\nsignals if the mass gap between the ground state and the excited state is at\nkeV scale.", "category": "hep-ph" }, { "text": "On the LHC sensitivity for non-thermalised hidden sectors: We show under rather general assumptions that hidden sectors that never reach\nthermal equilibrium in the early Universe are also inaccessible for the LHC. In\nother words, any particle that can be produced at the LHC must either have been\nin thermal equilibrium with the Standard Model at some point or must be\nproduced via the decays of another hidden sector particle that has been in\nthermal equilibrium. To reach this conclusion, we parametrise the cross section\nconnecting the Standard Model to the hidden sector in a very general way and\nuse methods from linear programming to calculate the largest possible number of\nLHC events compatible with the requirement of non-thermalisation. We find that\neven the HL-LHC cannot possibly produce more than a few events with energy\nabove 10 GeV involving states from a non-thermalised hidden sector.", "category": "hep-ph" }, { "text": "The effects of charmonium on the properties of the $1^{++}$ hidden charm\n poles in effective field theory: In this study, the properties of the $J^{PC}=1^{++}$ hidden charm poles are\nanalyzed under the variation of the bare 2P charmonium mass within the\neffective field theory proposed in Ref.[1]. The main focus of the current work\nis on the pole trajectory of the $\\chi_{c1}(2P)$ charmonium dressed by the $D\n\\bar{D}^*$ meson loops. It is shown that the trajectories of the pole change\nradically for values of the bare charmonium mass above a certain value and also\ndepending on how close the pole is to the threshold.", "category": "hep-ph" }, { "text": "The Higgs portal and an unified model for dark energy and dark matter: We examine a scenario where the Higgs boson is coupled to an additional\nsinglet scalar field which we identify with a quintessence field. We show that\nthis results in an unified picture of dark matter and dark energy, where dark\nenergy is the zero-mode classical field rolling the usual quintessence\npotential and the dark matter candidate is the quantum excitation (particle) of\nthe field, which is produced in the universe due to its coupling to the Higgs\nboson.", "category": "hep-ph" }, { "text": "Opportunities in Neutrino Theory -- a Snowmass White Paper: Neutrino masses are clear evidence for physics beyond the standard model and\nmuch more remains to be understood about the neutrino sector. We highlight some\nof the outstanding questions and research opportunities in neutrino theory. We\nshow that most of these questions are directly connected to the very rich\nexperimental program currently being pursued (or at least under serious\nconsideration) in the United States and worldwide. Finally, we also comment on\nthe state of the theoretical neutrino physics community in the U.S.", "category": "hep-ph" }, { "text": "RECO level \\sqrt{s}_{min} and subsystem \\sqrt{s}_{min}: improved global\n inclusive variables for measuring the new physics mass scale in missing\n energy events at hadron colliders: The variable \\sqrt{s}_{min} was originally proposed in arXiv:0812.1042 as a\nmodel-independent, global and fully inclusive measure of the new physics mass\nscale in missing energy events at hadron colliders. In the original incarnation\nof \\sqrt{s}_{min}, however, the connection to the new physics mass scale was\nblurred by the effects of the underlying event, most notably initial state\nradiation and multiple parton interactions. In this paper we advertize two\nimproved variants of the \\sqrt{s}_{min} variable, which overcome this problem.\nFirst we show that by evaluating the \\sqrt{s}_{min} variable at the RECO level,\nin terms of the reconstructed objects in the event, the effects from the\nunderlying event are significantly diminished and the nice correlation between\nthe peak in the \\sqrt{s}_{min}^{(reco)} distribution and the new physics mass\nscale is restored. Secondly, the underlying event problem can be avoided\naltogether when the \\sqrt{s}_{min} concept is applied to a subsystem of the\nevent which does not involve any QCD jets. We supply an analytic formula for\nthe resulting subsystem \\sqrt{s}_{min}^{(sub)} variable and show that its peak\nexhibits the usual correlation with the mass scale of the particles produced in\nthe subsystem. Finally, we contrast \\sqrt{s}_{min} to other popular inclusive\nvariables such as H_T, M_{Tgen} and M_{TTgen}. We illustrate our discussion\nwith several examples from supersymmetry, and with dilepton events from top\nquark pair production.", "category": "hep-ph" }, { "text": "Simulation of Beyond Standard Model Physics in Herwig++: We present a new approach for the simulation of Beyond Standard Model (BSM)\nphysics within the Herwig++ event generator. Our approach is more generic than\nprevious methods with the aim of minimising the effort of implementing further\nnew physics models. Spin correlations, which are important for BSM models due\nto new heavy fermions and bosons, are discussed and their effects demonstrated\nfor the Minimal Supersymmetric Standard Model (MSSM) and Randall-Sundrum Model\nusing our new framework.", "category": "hep-ph" }, { "text": "Hard Photon Pair Production at LEP: The production of photon pairs in $e^+e^-\\rightarrow f \\bar f \\gamma\\gamma$\nprocesses is studied using exact helicity amplitudes at tree level. Total cross\nsections, including initial state radiation effects, are given. They are\npresented in the case of quarks as a function of $y_{\\rm cut}$ in the JADE\nalgorithm. In the case of leptons we use cuts similar to the ones employed in a\nrecent L3 analysis. Masses of the final state fermions are taken into account\nwhen appropriate. The cross section $e^+e^-\\rightarrow \\tau^+ \\tau^-\n\\gamma\\gamma$ is about 10\\% larger when the $\\tau$ mass is neglected. We\nobtain, with a different method, results which are in good agreement with L3\nMontecarlo simulation.", "category": "hep-ph" }, { "text": "Nano-Hertz gravitational waves from collapsing domain walls associated\n with freeze-in dark matter in light of pulsar timing array observations: Evidence for a stochastic gravitational wave background in the nHz frequency\nband is recently reported by four pulsar timing array collaborations NANOGrav,\nEPTA, CPTA, and PPTA. It can be interpreted by gravitational waves from\ncollapsing domain walls in the early universe. We assume such domain walls\narising from the spontaneous breaking of a $Z_2$ symmetry in a scalar field\ntheory, where a tiny $Z_2$-violating potential is required to make domain walls\nunstable. We propose that this $Z_2$-violating potential is radiatively induced\nby a feeble Yukawa coupling between the scalar field and a fermion field, which\nis also responsible for dark matter production via the freeze-in mechanism.\nCombining the pulsar timing array data and the observed dark matter relic\ndensity, we find that the model parameters can be narrowed down to small\nranges.", "category": "hep-ph" }, { "text": "Direct Detection is testing Freeze-in: Dark Matter (DM) may belong to a hidden sector that is only feebly\ninteracting with the Standard Model (SM) and may have never been in thermal\nequilibrium in the Early Universe. In this case, the observed abundance of dark\nmatter particles could have built up through a process known as Freeze-in. We\nshow that, for the first time, direct detection experiments are testing this DM\nproduction mechanism. This applies to scenarios where the SM and hidden sectors\ncommunicate through a light mediator particle of mass less than a few MeV.\nThrough the exchange of such light mediator, the very same FIMP candidates can\nhave self-interactions that are in the range required to address the small\nscale structure issues of collisionless cold dark matter.", "category": "hep-ph" }, { "text": "Massive gluons and quarks and the equation of state obtained from SU(3)\n lattice QCD: We analyze recent results of SU(3) lattice QCD calculations with a\nphenomenological parametrization for the quark-gluon plasma equation of state\nbased on a quasi-particle picture with massive quarks and gluons. At high\ntemperature we obtain a good fit to the lattice data using perturbative thermal\nquark and gluon masses from an improved HTL scheme. At temperatures close to\nthe confinement phase transition the fitted masses increase above the\nperturbative value, and a non-zero (but small) bag constant is required to fit\nthe lattice data.", "category": "hep-ph" }, { "text": "Finite size source effects and the correlation of neutrino transition\n probabilities through supernova turbulence: (Abridged) The transition probabilities describing the evolution of a\nneutrino with a given energy along some ray through a turbulent supernova are\nrandom variates unique to each ray. If the source of the neutrinos were a point\nthen all neutrinos of a given energy and emitted at the same time which were\ndetected in some far off location would have seen the same turbulent profile\ntherefore their transition probabilities would be exactly correlated. But if\nthe source has a finite size then the profiles seen by neutrinos emitted from\ndifferent points at the source will have seen different turbulence and the\ncorrelation of the transition probabilities will be reduced. In this paper we\nstudy the correlation of the neutrino transition probabilities through\nturbulent supernova profiles as a function of the separation between the\nemission points using an isotropic and an anisotropic power spectrum for the\nrandom field used to model the turbulence. The spectral features in the high\ndensity resonance mixing channel of the next Galactic supernova neutrino burst\nmay be strongly obscured by large amplitude turbulence when it enters the\nsignal due to the finite size of the source while the presence of features in\nthe low density and non resonant mixing channels may persist, the exact amount\ndepending upon the degree of anisotropy of the turbulence.", "category": "hep-ph" }, { "text": "Flavor-dependent U(3) Nambu Jona Lasinio coupling constant: A non-perturbative one gluon exchange quark-antiquark interaction is\nconsidered to compute flavor dependent U(3) Nambu-Jona-Lasinio (NJL)-type\ninteraction of the form $G_{ij, \\Gamma} (\\bar{\\psi} \\lambda_i \\Gamma \\psi ) (\n\\bar{\\psi} \\lambda_j \\Gamma \\psi)$ for $i,j=0...8$ and $\\Gamma=I, i \\gamma_5$\nfrom one loop polarization process with non degenerate u-d-s quark effective\nmasses. The resulting NJL-type coupling constants in all channels are resolved\nin the long-wavelength limit and numerical results are presented for different\nchoices of an effective gluon propagator. Leading deviations with respect to a\nflavor symmetric coupling constant are found to be of the order of\n$(M_{f_2}^*-M_{f_1}^*)^n/(M_{f_2}^*+M_{f_1}^*)^n$, for $n=1,2$, where\n$M_{f_i}^*$ are the effective masses of quarks $f_1,f_2=u, d$ and $s$. The\nscalar channel coupling constants $G_{ij, s}$ can be considerably smaller than\npseudoscalar ones. The effect of the flavor-dependence of coupling constants\nfor the masses of pions and kaons may be nearly of the same order of magnitude\nas the effect of the u,d and s quark mass non-degeneracy. The effect of these\ncoupling constants is also verified for some of the light scalar mesons masses,\nusually described by quark-antiquark states, and for some observables of the\npseudoscalar mesons.", "category": "hep-ph" }, { "text": "Simulation of Proton and Iron Induced Extensive Air Showers: The reliable simulation of extensive air showers induced by different primary\nparticles (e. g. proton, iron, gamma etc.) is of great importance in high\nenergy cosmic ray research. The CORSIKA is a standard Monte-Carlo simulation\npackage to simulate the four dimensional evolution of Extensive Air Shower\n(EAS) in the atmosphere initiated by gamma, hadrons and nuclei. CORSIKA has\ndifferent high energy interaction models like DPMJET, QGSJET, NEXUS, SIBYLL,\nVENUS and EPOS which are based on different theoretical frameworks. The\ninfluence of different hadronic interaction models, viz., QGSJET and DPMJET on\nthe lateral distribution functions (LDF) and muon to electron ratio of cosmic\nray EAS induced by 10^17 eV to 10^20 eV proton and iron primaries are explored\nin this work.", "category": "hep-ph" }, { "text": "Probing Supersymmetric Dark Matter and the Electroweak Sector using\n Vector Boson Fusion Processes: A Snowmass Whitepaper: Vector boson fusion (VBF) processes at the Large Hadron Collider (LHC)\nprovide a unique opportunity to search for new physics with electroweak\ncouplings. Two studies are presented: (i) A search of supersymmetric dark\nmatter in the final state of two VBF jets and large missing transverse energy\nis presented at 14 TeV. Prospects for determining the dark matter relic density\nare studied for the cases of Wino and Bino-Higgsino dark matter. The LHC could\nprobe Wino dark matter with mass up to approximately 600 GeV with a luminosity\nof 1000 fb$^{-1}$. (ii) A search for the chargino/neutralino system in the\nfinal state of two VBF jets, missing transverse energy and two $\\tau$'s (light\nstau case) and light lepton $e$ and $\\mu$ (light slepton case). The $5 \\sigma$\nmass reach at 300 fb$^{-1}$ (1000 fb$^{-1}$) of LHC14 for inclusive and\nopposite-sign $\\tau$ pairs are 250 GeV (300 GeV) and 200 GeV (250 GeV),\nrespectively, for $\\Delta M \\, = \\, m_{\\tilde{\\tau}_1} - m_{\\neu{1}} \\, = \\,\n30$ GeV. For $\\Delta M \\, = \\, 15$ GeV, the $3 \\sigma$ mass reach at 300\nfb$^{-1}$ (1000 fb$^{-1}$) of LHC14 for inclusive $\\tau$ pairs is 180 GeV. The\n$5 \\sigma$ mass reach at 300 fb$^{-1}$ (1000 fb$^{-1}$) of LHC14 for inclusive\nand opposite-sign $\\mu$ pairs are approximately 350 GeV (400 GeV) and 300 GeV\n(350 GeV), respectively. The mass reaches in the same-sign final state cases\nare similar to those in the opposite-sign cases.", "category": "hep-ph" }, { "text": "Matching to all orders and power corrections in heavy quark effective\n theory: This talk reports on various aspects of the divergence of perturbative\nexpansions in the context of matching QCD onto heavy quark effective theory.\nImplications for exclusive and inclusive decays of heavy mesons are discussed.", "category": "hep-ph" }, { "text": "Very High Energy Cosmic Rays from Centaurus A: Centaurus A is the nearest radio-loud AGN and is detected from radio to very\nhigh energy gamma-rays. Its nuclear spectral energy distribution shows two\npeaks, one in the far-infrared band and another at about 150 keV. By assuming\nthe second peak is due to the electron synchrotron emission and the power index\nfor the differential spectrum of the very high energy cosmic ray proton to be\n2.7 we show that only pp interaction is responsible for the observed GeV-TeV\nemission from Centaurus A. We also found that indeed many very high energy\ncosmic ray protons from Centaurus A can arrive on Earth thus supporting the\nrecent observation of two events by Pierre Auger Observatory.", "category": "hep-ph" }, { "text": "Leptogenesis as an origin of dark matter and baryon asymmetries in the\n E6 inspired SUSY models: We explore leptogenesis within the E6 inspired U(1) extension of the MSSM in\nwhich exact custodial symmetry forbids tree-level flavour-changing transitions\nand the most dangerous baryon and lepton number violating operators. This\nsupersymmetric (SUSY) model involves extra exotic matter beyond the MSSM. In\nthe simplest phenomenologically viable scenarios the lightest exotic fermions\nare neutral and stable. These states should be substantially lighter than 1 eV\nforming hot dark matter in the Universe. The low-energy effective Lagrangian of\nthe SUSY model under consideration possesses an approximate global U(1)_E\nsymmetry associated with the exotic states. The U(1)_E symmetry is explicitly\nbroken because of the interactions between the right-handed neutrino\nsuperfields and exotic matter supermultiplets. As a consequence the decays of\nthe lightest right-handed neutrino/sneutrino give rise to both U(1)_E and\nU(1)_{B-L} asymmetries. When all right-handed neutrino/sneutrino are relatively\nlight \\sim 10^6-10^7 GeV the appropriate amount of the baryon asymmetry can be\ninduced via these decays if the Yukawa couplings of the lightest right-handed\nneutrino superfields to the exotic matter supermultiplets vary between\n10^{-4}-10^{-3}.", "category": "hep-ph" }, { "text": "Universality of traveling waves with QCD running coupling: ``Geometric scaling'', i.e. the dependence of DIS cross-sections on the ratio\nQ/Q_S, where Q_S(Y) is the rapidity-dependent \\saturation scale, can be\ntheoretically obtained from universal ``traveling wave'' solutions of the\nnonlinear Balitsky-Kovchegov (BK) QCD evolution equation at fixed coupling. We\nexamine the similar mean-field predictions beyond leading-logarithmic order,\nincluding running QCD coupling.", "category": "hep-ph" }, { "text": "Axial anomaly and vector meson dominance model: The dispersive representation of axial anomaly leads to the anomaly sum rules\n(ASRs), exact nonperturbative relations in QCD. The analytical continuation of\nthe ASRs to the time-like region is performed. The transition form factors of\n$\\pi^0$, $\\eta$ and $\\eta'$ mesons in this region are calculated. A good\nagreement with the available experimental data is found. Based on the ASRs, we\nhave provided the foundations for the vector meson dominance model in these\nprocesses.", "category": "hep-ph" }, { "text": "Flavor-Changing Neutral Current Constraints in Topcolor-Assisted\n Technicolor: It is argued that the topcolor models recently proposed by Hill [1] may face\nsignificant constraints from flavor-changing neutral current processes (such as\n$B-\\bar{B}$ mixing) unless the mixing angles between down-type quarks are\nsmall. The flavor-changing processes are mediated by scalar bound states which\nare likely to be light as a result of the near critical dynamics of the\n$b$-quark sector. The consequences of the latter on the bottom quark mass are\nalso briefly discussed.", "category": "hep-ph" }, { "text": "Exclusive diffractive processes in electron-ion collisions: We present a new technique to calculate the cross-section for diffractive\nvector meson production and DVCS in electron-ion collisions based on the dipole\nmodel. The measurement of these processes can provide valuable information on\nnon-linear QCD phenomena, such as gluon saturation, and is the the only known\nway to gain insight into the spatial distribution of gluons in nuclei. We\npresent predictions of differential cross-section distribution $d\\sigma/dQ^2$\nand $d\\sigma/dt$ for $J/\\psi$ and $\\phi$ meson production for diffractive\nprocesses of heavy nuclei and demonstrate the feasibility of extracting the\ngluon source distribution of heavy nuclei, F(b), from coherent diffraction. We\nbriefly introduce a new event generator based on our method that can be used\nfor studying exclusive diffractive processes at a future electron-ion collider.", "category": "hep-ph" }, { "text": "A Non-perturbative Treatment of Heavy Quarks and Mesons: A formalism for studying heavy quarks in terms of model Dyson-Schwinger\nequations is developed. The formalism is the natural extension of a technique\nwhich has proved successful in a number of studies of light hadron physics. The\ndressed heavy quark propagator, calculated to leading order in the inverse\nquark mass, is incorporated in a treatment of mesons consisting of a heavy\nquark and light antiquark via the ladder approximation Bethe-Salpeter equation.\nIn the limit of infinite heavy quark mass the model is found to respect the\nspectrum degeneracies present in Heavy Quark Effective Theory. An exploratory\nnumerical analysis of a simple form of the model is carried out to assess its\nviability for studying $D$ and $B$ mesons.", "category": "hep-ph" }, { "text": "Electroweak Baryogenesis: Concrete in a SUSY Model with a Gauge Singlet: SUSY models with a gauge singlet easily allow for a strong first order\nelectroweak phase transition (EWPT) if the vevs of the singlet and Higgs fields\nare of comparable size. We discuss the profile of the stationary expanding\nbubble wall and CP-violation in the effective potential, in particular\ntransitional CP-violation inside the bubble wall during the EWPT. The\ndispersion relations for charginos contain CP-violating terms in the WKB\napproximation. These enter as source terms in the Boltzmann equations for the\n(particle--antiparticle) chemical potentials and fuel the creation of a baryon\nasymmetry through the weak sphaleron in the hot phase. This is worked out for\nconcrete parameters.", "category": "hep-ph" }, { "text": "The Y(2175) State in the QCD Sum Rule: We study the mass of the state Y(2175) of J^{PC} = 1^{--} in the QCD sum\nrule. We construct both the diquark-antidiquark currents (ss)(s_bar s_bar) and\nthe meson-meson currents (s_bar s)(s_bar s). We find that there are two\nindependent currents for both cases, and derive the relations between them. The\nOPE convergence of these two currents is sufficiently fast, which enables us to\nperform good sum rule analysis. Both the SVZ sum rule and the finite energy sum\nrule lead to a mass around 2.3+-0.4 GeV, which is consistent with the observed\nmass within the uncertainties of the present QCD sum rule. The coupling of the\nfour-quark currents to lower lying states such as \\phi(1020) turns out to be\nrather small. We also discuss possible decay properties of Y(2175) if it is a\ntetraquark state.", "category": "hep-ph" }, { "text": "Positronium energy levels at order $m \u03b1^7$: Product contributions\n in the two-photon-annihilation channel: Ongoing improvements in the measurement of positronium transition intervals\nmotivate the calculation of the $O(m \\alpha^7)$ corrections to these intervals.\nIn this work we focus on corrections to the spin-singlet parapositronium\nenergies involving virtual annihilation to two photons in an intermediate\nstate. We have evaluated all contributions to the positronium S-state energy\nlevels that can be written as the product of a one-loop correction on one side\nof the annihilation event and another one-loop correction on the other side.\nThese effects contribute $\\Delta E = -0.561971(25) m \\alpha^7/\\pi^3$ to the\nparapositronium ground state energy.", "category": "hep-ph" }, { "text": "Calculation of fragmentation functions in two-hadron semi-inclusive\n processes: We investigate the properties of interference fragmentation functions arising\nfrom the emission of two leading hadrons inside the same jet for inclusive\nlepton-nucleon deep-inelastic scattering. Using an extended spectator model for\nthe mechanism of the hadronization, we give a complete calculation and\nnumerical estimates for the examples of a proton-pion pair produced with\ninvariant mass on the Roper resonance, and of two pions produced with invariant\nmass close to the $\\rho$ mass. We discuss azimuthal angular dependence of the\nleading order cross section to point up favourable conditions for extracting\ntransversity from experimental data.", "category": "hep-ph" }, { "text": "Natural Suppression of Proton Decay in Supersymmetric Type III Seesaw\n Models: Supersymmetric standard model (MSSM) has two sources of rapid proton decay:\n(i) R-parity breaking terms and (ii) higher dimensional Planck induced\nB-violating terms; its extensions to include neutrino masses via the type I\nseesaw mechanism need not have the first of these problems due to the existence\nof B-L as a gauge symmetry but for sure always have the second one. If instead,\nneutrino masses are explained in a type III seesaw extension of the standard\nmodel, an anomaly free gauge symmetry different from B-L is known to exist. In\nthis note, it is shown that a realistic supersymmetric versions of this model\ncan be constructed (MSSM as well as SUSY left-right with type III seesaw) which\nforbid the R-parity violating couplings of MSSM and suppress Planck scale\ncontributions to proton decay. The degree of suppression of the latter depends\non the weak gauge group. For the left-right case, the suppression to the\ndesired level is easily achieved.", "category": "hep-ph" }, { "text": "Combined constraints on the SUSY parameter space from $\u0394r$ ~and\n Higgs boson search: Combining the constraints coming from the ~$M_W$ ~measurements and the\nunsuccesful search for the Higgs boson at LEP we determine in the framework of\nMSSM the allowed mass regions for the lighter scalar partner of the top quark.\nFor a heavy top quark particularily strong bounds are obtained for low values\nof ~$\\tan\\beta\\equiv v_2/v_1$ ~and light bottom squark.", "category": "hep-ph" }, { "text": "VISH$\u03bd$: a unified solution to five SM shortcomings with a protected\n electroweak scale: We propose a Standard Model extension, coined VISH$\\nu$ (Variant-axIon Seesaw\nHiggs $\\nu$-trino), that is an $N_{\\text{DW}} = 1$ variation of its\npredecessor, the $\\nu$DFSZ model. In accounting for the origin of neutrino\nmasses, dark matter and the baryon asymmetry of the universe, VISH$\\nu$\ninherits the explanatory power of $\\nu$DFSZ while, of course, resolving the\nstrong $CP$ problem. In both models, the electroweak scale is naturally\nprotected from a high seesaw scale that is identified with the Peccei-Quinn\n(PQ) spontaneous symmetry breaking scale. Through a flavour variant coupling\nstructure, VISH$\\nu$ evades a domain wall problem, extending the cosmological\nreach of the $\\nu$DFSZ to include a viable period of inflation. The primary\nfocus of this paper is on the inflationary dynamics of VISH$\\nu$ and their\nnaturalness in the sense of radiative stability. We find that non-minimal\ngravitational couplings, generically developed by the VISH$\\nu$ scalar fields,\nnaturally support a viable inflaton field which typically has both a PQ scalar\nand Higgs component. An axion mass window [$40\\mu\\text{eV}, \\sim 2\\text{meV}$]\naccessible to forthcoming searches, results for the case where PQ symmetry is\nrestored during the (p)reheating phase.", "category": "hep-ph" }, { "text": "$V_{cb}$ from the semileptonic decay $B\\to D \\ell \\bar\u03bd_{\\ell}$ and\n the properties of the $D$ meson distribution amplitude: The improved QCD light-cone sum rule (LCSR) provides an effective way to deal\nwith the heavy-to-light transition form factors (TFFs). Firstly, we adopt the\nimproved LCSR approach to deal with the $B\\to D$ TFF $f^{+}(q^2)$ up to twist-4\naccuracy. Due to the elimination of the most uncertain twist-3 contribution and\nthe large suppression of the twist-4 contribution, the obtained LCSR shall\nprovide us a good platform for testing the $D$-meson leading-twist DA. For the\npurpose, we suggest a new model for the $D$-meson leading-twist DA\n($\\phi_{3D}$), whose longitudinal behavior is dominantly determined by a\nparameter $B$. Moreover, we find its second Gegenbauer moment $a^D_2\\sim B$.\nVarying $B$ within certain region, one can conveniently mimic the $D$-meson DA\nbehavior suggested in the literature. Inversely, by comparing the estimations\nwith the experimental data on the $D$-meson involved processes, one can get a\npossible range for the parameter $B$ and a determined behavior for the\n$D$-meson DA. Secondly, we discuss the $B\\to D$ TFF at the maximum recoil\nregion and present a detailed comparison of it with the pQCD estimation and the\nexperimental measurements. Thirdly, by applying the LCSR on $f^{+}(q^2)$, we\nstudy the CKM matrix element $\\Vcb$ together with its uncertainties by adopting\ntwo types of processes, i.e. the $B^0/\\bar{B}^0$-type and the $B^{\\pm}$-type.\nIt is noted that a smaller $B \\precsim 0.20$ shows a better agreement with the\nexperimental value on $\\Vcb$. For example, for the case of $B=0.00$, we obtain\n$|V_{cb}|(B^0/\\bar{B}^0-{\\rm type})=(41.28 {^{+5.68}_{-4.82}}\n{^{+1.13}_{-1.16}}) \\times 10^{-3}$ and $|V_{cb}|(B^{\\pm}-{\\rm type})=(40.44\n{^{+5.56}_{-4.72}} {^{+0.98}_{-1.00}}) \\times 10^{-3}$, whose first (second)\nuncertainty comes from the squared average of the mentioned theoretical\n(experimental) uncertainties.", "category": "hep-ph" }, { "text": "Properties of the Quark Gluon Plasma: A lattice perspective: We discuss results from lattice calculations for a few observables that are\nsensitive to different length scales in the high temperature phase of QCD and\ncan give insight into its non-perturbative structure. We compare lattice\nresults with perturbative calculations at high temperature obtained for\nvanishing and non-vanishing quark chemical potential.", "category": "hep-ph" }, { "text": "Single Top Production as a Probe of Heavy Resonances: The single top quark final state provides sensitivity to new heavy resonances\nproduced in proton-proton collisions at the Large Hadron Collider.\nParticularly, the single top plus quark final state appears in models with\nheavy charged bosons or scalars, or in models with flavor-changing neutral\ncurrents involving the top quark. The cross sections and final state kinematics\ndistinguish such models from each other and from standard model backgrounds.\nSeveral models of resonances decaying to a single top quark final state are\npresented and their phenomenology is discussed.", "category": "hep-ph" }, { "text": "Monte-Carlo simulation of lepton pair production in \"p pbar --> l+l- +\n X\" events at E_beam = 14 GeV: The lepton pair production in collisions of antiproton beam (E_beam = 14 GeV)\nwith proton target is studied on the basis of event samples simulated with\nPYTHIA6 generator. Two types of quark level subprocesses are considered. The\nfirst one goes through the production of virtual photon which converts into\nlepton pair (q qbar --> gamma* --> l+l-) having a continuous energy spectrum of\nthe final lepton pair invariant mass. The other subprocess proceeds through the\nJ/Psi resonance production (p pbar --> J/Psi + X --> l+l- + X) with the\nfollowing decay of J/Psi into a pair of leptons. The distributions of different\nkinematical variables which may be useful for the design of the muon system and\nthe electromagnetic calorimeter of the detector of PANDA experiment at FAIR are\npresented. The analysis of these distribution shows the possibility to measure\nthe proton structure function in a new kinematical region defined by the\ntime-like values of the square of the momentum transferred 1 < Q^2 < 6.25 GeV^2\nand withing a rather wide interval 0.05 < x < 0.7 of Bjorken x-variable. The\nproblems due to the presence of fake leptons that appear from meson decays, as\nwell as due to the background caused by minimum bias events and other QCD\nprocesses, are also discussed. The set of cuts which allows one to separate the\nsignal events with lepton pairs from this kind of background events is\nproposed.", "category": "hep-ph" }, { "text": "Precision Electroweak Physics at Future Collider Experiments: We present an overview of the present status and prospects for progress in\nelectroweak measurements at future collider experiments leading to precision\ntests of the Standard Model of Electroweak Interactions. Special attention is\npaid to the measurement of the W mass, the effective weak mixing angle, and the\ndetermination of the top quark mass. Their constraints on the Higgs boson mass\nare discussed.", "category": "hep-ph" }, { "text": "CP-Violation in b \\to s \\ell^{+} \\ell^{-} transition Beyond the Standard\n Model: In this study the CP-asymmetry in the b \\to s \\ell^{+} \\ell^{-} transition\nwas investigated in minimal extension of the Standard Model where C_{9}^{eff}\nreceives an extra weak phase due to the new physics effects. We observed that\nCP-Violation asymmetry can be measurable in the framework of scenario mentioned\nabove.", "category": "hep-ph" }, { "text": "LHC signals for neutrino mass model in bilinear R-parity violating mAMSB: We investigate a neutrino mass model in which the neutrino data is accounted\nfor by bilinear R-parity violating supersymmetry with anomaly mediated\nsupersymmetry breaking. We focus on the CERN Large Hadron Collider (LHC)\nphenomenology, studying the reach of generic supersymmetry search channels with\nleptons, missing energy and jets. A special feature of this model is the\nexistence of long lived neutralinos and charginos which decay inside the\ndetector leading to detached vertices. We demonstrate that the largest reach is\nobtained in the displaced vertices channel and that practically all of the\nreasonable parameter space will be covered with an integrated luminosity of 10\nfb-1. We also compare the displaced vertex reaches of the LHC and Tevatron.", "category": "hep-ph" }, { "text": "Direct CP Violation in D -> hh Decays: Evidence of CP violation in the charm sector has been observed recently by\nthe LHCb and CDF Collaborations. The issue of whether it can be accommodated\nwithin the standard model (SM) is examined in this talk. We conclude that the\nCP asymmetry difference $\\Delta a_{CP}^{\\rm dir}$ between $D^0 \\to K^+ K^-$ and\n$D^0 \\to \\pi^+ \\pi^-$ is of order $-(0.14\\sim 0.15)%$. If the improved\ntheoretical estimate of $\\Delta a_{CP}^{\\rm dir}$ in the SM remains to be a few\nper mille and the experimental measurement continues to be large with more\nstatistics in the future, it will be clear evidence of physics beyond the SM in\nthe charm sector.", "category": "hep-ph" }, { "text": "Nonexistence of the Longitudinal Polarisation of a Massive Gauge Bosons: This paper has been withdrawn by the authors due to some errors.", "category": "hep-ph" }, { "text": "Landau-Zener problem in a three-level neutrino system with non-linear\n time dependence: We consider the level-crossing problem in a three-level system with\nnon-linearly time-varying Hamiltonian (time-dependence $t^{-3}$). We study the\nvalidity of the so-called independent crossing approximation in the\nLandau-Zener model by making comparison with results obtained numerically in\ndensity matrix approach. We also demonstrate the failure of the so-called\n\"nearest zero\" approximation of the Landau-Zener level-crossing probability\nintegral.", "category": "hep-ph" }, { "text": "Non-relativistic bound states at finite temperature (I): the hydrogen\n atom: We illustrate how to apply modern effective field theory techniques and\ndimensional regularization to factorize the various scales which appear in\nnon-relativistic bound states at finite temperature. We focus here on the\nsimplest case: the hydrogen atom. We discuss in detail the interplay of the\nhard, soft and ultrasoft scales of the non-relativistic system at zero\ntemperature with the additional scales induced at finite temperature. We also\ncomment on the implications of our results for heavy quarkonium bound states in\nthe quark gluon plasma.", "category": "hep-ph" }, { "text": "QCD Saturation and Deuteron-Nucleus Collisions: We make quantitative predictions for the rapidity and centrality dependencies\nof hadron multiplicities in dA collisions at RHIC basing on the ideas of parton\nsaturation in the Color Glass Condensate.", "category": "hep-ph" }, { "text": "Could the excess seen at 124-126 GeV be due to the Randall-Sundrum\n Radion?: Current Higgs boson searches in various channels at the LHC point to an\nexcess at around 124-126 GeV due to a possibly standard-model-like Higgs boson.\nIf one examines more closely the channels (\\gamma\\gamma, WW*, and ZZ*) that\nhave excess, this \"Higgs boson\" may be the Randall-Sundrum radion \\phi. Because\nof the trace anomaly the radion has stronger couplings to the photon and gluon\npairs. Thus, it will enhance the production rates into gg and \\gamma\\gamma\nwhile those for WW*, ZZ* and b\\bar b are reduced relative to their\nstandard-model values. We show that it can match well with the data from CMS\nfor m_\\phi = 124 GeV and the required scale \\Lambda_\\phi ~ <\\phi > is about\n0.68 TeV.", "category": "hep-ph" }, { "text": "Investigation of next-to-leading effects in CCFM: The effect of formally next-to-leading contributions to the CCFM evolution\nequation are discussed.", "category": "hep-ph" }, { "text": "Nonabelian dark matter models for 3.5 keV X-rays: A recent analysis of XXM-Newton data reveals the possible presence of an\nX-ray line at approximately 3.55 keV, which is not readily explained by known\natomic transitions. Numerous models of eV-scale decaying dark matter have been\nproposed to explain this signal. Here we explore models of multicomponent\nnonabelian dark matter with typical mass ~ 1-10 GeV (higher values being\nallowed in some models) and eV-scale splittings that arise naturally from the\nbreaking of the nonabelian gauge symmetry. Kinetic mixing between the photon\nand the hidden sector gauge bosons can occur through a dimension-5 or 6\noperator. Radiative decays of the excited states proceed through transition\nmagnetic moments that appear at one loop. The decaying excited states can\neither be primordial or else produced by upscattering of the lighter dark\nmatter states. These models are significantly constrained by direct dark matter\nsearches or cosmic microwave background distortions, and are potentially\ntestable in fixed target experiments that search for hidden photons. We note\nthat the upscattering mechanism could be distinguished from decays in future\nobservations if sources with different dark matter velocity dispersions seem to\nrequire different values of the scattering cross section to match the observed\nline strengths.", "category": "hep-ph" }, { "text": "Two-Photon Exchange in Electron-Proton Elastic Scattering: Theory Update: Recent theoretical developments in the studies of two-photon exchange effects\nin elastic electron-proton scattering are reviewed. Two-photon exchange\nmechanism is considered a likely source of discrepancy between polarized and\nunpolarized experimental measurements of the proton electric form factor at\nmomentum transfers of several GeV$^2$. This mechanism predicts measurable\neffects that are currently studied experimentally.", "category": "hep-ph" }, { "text": "NMSSM in gauge-mediated SUSY breaking without domain wall problem: A problem of the gauge-mediated SUSY breaking model is its difficulty to\ngenerate a natural value of mu/Bmu, while the NMSSM is a natural framework to\nsolve the mu/Bmu problem. The NMSSM in gauge-mediated SUSY breaking in its\noriginal form does not work well since the singlet field cannot develop a\ndesired vacuum expectation value. It also suffers from the cosmological domain\nwall problem. We study an extension of the model to include additional\nvector-like matter, which is charged under the hidden QCD. It is shown that\nthis simple extension solves both the problems. We study phenomenological and\ncosmological implications of this extended models. The lightest Higgs mass can\nbe as large as 130-140 GeV for some model points.", "category": "hep-ph" }, { "text": "Reconstructing CMSSM parameters at the LHC with $\\sqrt{s}=14$ TeV via\n the golden decay channel: We identify a benchmark point in the CMSSM's heavy stau-coannihilation\nregion, which is favored by experiments, and demonstrate that it could be\naccessible to the LHC at $\\sqrt{s}=14$ TeV with 300/fb of integrated luminosity\nvia a golden decay measurement. With Monte-Carlo, we simulate sparticle\nproduction and subsequent golden decay at the event level and perform\npseudo-measurements of sparticle masses from kinematic endpoints in invariant\nmass distributions. We find that two lightest neutralino masses and the first\nand second generation left-handed slepton and squark masses could be rather\nprecisely measured with correlated uncertainties. We investigate whether from\nsuch measurements one could determine the CMSSM's Lagrangian parameters by\nincluding a likelihood from our pseudo-measurements of sparticle masses in a\nBayesian analysis of the CMSSM's parameter space. We find that the CMSSM's\nparameters can be accurately determined, with the exception of the common\ntrilinear parameter. Experimental measurements of the relic density by Planck\nand the Higgs boson's mass slightly improve this determination, especially for\nthe common trilinear parameter. Finally, within our benchmark scenario, we show\nthat the neutralino dark matter will be accessible to direct searches in future\none tonne detectors.", "category": "hep-ph" }, { "text": "Phenomenology of Hidden Valleys at Hadron Colliders: We study the phenomenology of, and search techniques for, a class of \"Hidden\nValleys.\" These models are characterized by low mass (well below a TeV) bound\nstates resulting from a confining gauge interaction in a hidden sector; the\nstates include a spin-one resonance that can decay to lepton pairs. Assuming\nthat the hidden sector communicates to the Standard Model (SM) through TeV\nsuppressed operators, taking into account the constraint from the $Z$ pole\nphysics at LEP, searches at Tevatron may be difficult in the particular class\nof Hidden Valleys we consider, so that we concentrate on the searches at the\nLHC. Hidden Valley events are characterized by high multiplicities of jets and\nleptons in the final state. Depending on the scale of confinement in the hidden\nsector, the events are typically more spherical, with lower thrust and higher\nincidences of isolated leptons, than those from the SM background processes.\nMost notably, high cluster invariant mass and very narrow, low mass resonances\nin lepton pairs are the key observables to identify the signal. We use these\ncharacteristics to develop a set of cuts to separate the Hidden Valley from SM,\nand show that with these cuts LHC has a significant reach in the parameter\nspace. Our strategies are quite general and should apply well beyond the\nparticular class of models studied here.", "category": "hep-ph" }, { "text": "Suppression of Bremsstrahlung at Non-Zero Temperature: The first-order bremsstrahlung emission spectrum is $\\alpha d\\omega/\\omega$\nat zero temperature. If the radiation is emitted into a region that contains a\nthermal distribution of photons, then the rate is increased by a factor\n$1+N(\\omega)$ where $N(\\omega)$ is the Bose-Einstein function. The stimulated\nemission changes the spectrum to $\\alpha Td\\omega/\\omega^{2}$ for $\\omega\\ll\nT$. If this were correct, an infinite amount of energy would be radiated in the\nlow frequency modes. This unphysical result indicates a breakdown of\nperturbation theory. The paper computes the bremsstrahlung rate to all orders\nof perturbation theory, neglecting the recoil of the charged particle. When the\nperturbation series is summed, it has a different low-energy behavior. For\n$\\omega\\ll\\alpha T$, the spectrum is independent of $\\omega$ and has a value\nproportional to $d\\omega/\\alpha T$ .", "category": "hep-ph" }, { "text": "Charmonium decay in the C3P0 Model: In this work, we use the $C^3P_{\\,0}$ model to calculate the decay widths of\nthe low lying charmonium $J^{PC}=1^{--}$ states, nominally $J/\\psi(1S)$ and\n$\\psi(2S)$, in the following common channels: $\\rho\\,\\pi$, $\\omega\\,\\eta$,\n$\\omega\\,\\eta^\\prime$, $K^{\\ast +}\\,K^-$, $K^{\\ast 0}\\,\\bar{K}^0$,\n$\\phi\\,\\eta$, $\\phi\\,\\eta^\\prime$.", "category": "hep-ph" }, { "text": "Probing Planck Scale Spacetime By Cavity Opto-Atomic $^{87}$Rb\n Interferometry: The project of \\emph{\"quantum spacetime phenomenology\"} focuses on searching\npragmatically for the Planck scale quantum features of spacetime. Among these\nfeatures is the existence of a characteristic length scale addressed commonly\nby effective approaches to quantum gravity (QG). This characteristic length\nscale could be realized, for instance and simply, by generalizing the standard\nHeisenberg uncertainty principle (HUP) to a \\emph{\"generalized uncertainty\nprinciple\"} (GUP). While usually it is expected that phenomena belonging to the\nrealm of QG are essentially probable solely at the so-called Planck energy,\nhere we show how a GUP proposal containing the most general modification of\ncoordinate representation of the momentum operator could be probed by a\n\\emph{\"cold atomic ensemble recoil experiment\"} (CARE) as a low energy quantum\nsystem. This proposed atomic interferometer setup has advantages over the\nconventional architectures owing to the enclosure in a high finesse optical\ncavity which is supported by a new class of low power consumption integrated\ndevices known as \\emph{\"micro-electro-opto-mechanical systems\"} (MEOMS). The\nproposed system comprises of a micro mechanical oscillator instead of spherical\nconfocal mirrors as one of the components of high finesse optical cavity. In\nthe framework of a bottom-up QG phenomenological viewpoint and by taking into\naccount the measurement accuracy realized for the fine structure constant (FSC)\nfrom the Rubidium ($^{87}$Rb) CARE, we set some constraints as upper bounds on\nthe characteristic parameters of the underlying GUP. In the case of\nsuperposition of the possible GUP modification terms, we managed to set a tight\nconstraint as $0.999978<\\lambda_0<1.00002$ for the dimensionless characteristic\nparameter.", "category": "hep-ph" }, { "text": "Energetics of neutrinos in neutron stars: I review our proof that long range forces induced by the exchange of massless\nneutrino-antineutrino pairs do not affect the stability of neutron stars.", "category": "hep-ph" }, { "text": "The description of $F_2$ at low $Q^2$: We analyse the data for the proton structure function $F_2$ over the entire\n$Q^2$ domain, including especially low $Q^2$, in terms of perturbative and\nnon-perturbative QCD contributions. The small distance configurations are given\nby perturbative QCD, while the large distance contributions are given by the\nvector dominance model and, for the higher mass $q \\bar{q}$ states, by the\nadditive quark approach. The interference between states of different\n$q\\bar{q}$ mass (in the perturbative contribution) is found to play a crucial\nrole in obtaining an excellent description of the data throughout the whole\n$Q^2$ region, including photoproduction.", "category": "hep-ph" }, { "text": "Double transverse spin asymmetries in vector boson production: We investigate a helicity non-flip double transverse spin asymmetry in vector\nboson production in hadron-hadron scattering, which was first considered by\nRalston and Soper at the tree level. It does not involve transversity functions\nand in principle also arises in W-boson production for which we present the\nexpressions. The asymmetry requires observing the transverse momentum of the\nvector boson, but it is not suppressed by explicit inverse powers of a large\nenergy scale. However, as we will show, inclusion of Sudakov factors causes\nsuppression of the asymmetry, which increases with energy. Moreover, the\nasymmetry is shown to be approximately proportional to x_1 g_1(x_1) x_2 \\bar\ng_1(x_2), which gives rise to additional suppression at small values of the\nlight cone momentum fractions. This implies that it is negligible for Z or W\nproduction and is mainly of interest for \\gamma^* at low energies. We also\ncompare the asymmetry with other types of double transverse spin asymmetries\nand discuss how to disentangle them.", "category": "hep-ph" }, { "text": "A Refined Analysis on the $X(3872)$ Resonance: We study the property of the $X(3872)$ meson by analyzing the $B\\to K D\\bar\nD^*$ and $B\\to K J/\\psi \\pi^+\\pi^-$ decay processes. The competition between\nthe rescattering mediated through a Breit-Wigner resonance and the rescattering\ngenerated from a local $D\\bar{D}^* \\to D\\bar{D}^*$ interaction is carefully\nstudied through an effective lagrangian approach. Three different fits are\nperformed: pure Breit-Wigner case, pure $D\\bar{D}^*$ molecule case with only\nlocal rescattering vertices (generated by the loop chain), and the mixed case.\nIt is found that data supports the picture where X(3872) is mainly a ($\\bar\ncc$) Breit-Wigner resonance with a small contribution to the self-energy\ngenerated by $\\bar DD^*$ final state interaction. For our optimal fit, the pole\nmass and width are found to be: $M_X=3871.2\\pm0.7$MeV and\n$\\Gamma_X=6.5\\pm1.2$MeV.", "category": "hep-ph" }, { "text": "Renormalization Group Improved Exponentiation of Soft Gluons in QCD: We extend the methods of Yennie, Frautschi and Suura to QCD for the summation\nof soft gluon effects in which infrared singularities are cancelled to all\norders in $\\alpha_s$. An explicit formula for the respective \\rngp improved\nexponentiated cross section is obtained for $q+\\bbar{{q'}}\\to q+\\bbar{{q'}}+\nn(G)$ at SSC energies. Possible applications are discussed.", "category": "hep-ph" }, { "text": "Heavy Quark Expansions for Inclusive Heavy-Flavour Decays and the\n Lifetimes of Charm and Beauty Hadrons: Inclusive heavy-flavour decays can be described through $1/m_Q$ expansions\nderived from QCD with the help of an operator product expansion. I sketch their\nmethodology and apply them first to semileptonic B decays; $|V(cb)|$ can be\nextracted from $\\Gamma _{SL}(B)$ and $\\bar B \\to l \\nu D^*$ with the result:\n$|V(cb)|_{incl} = 0.0413 \\pm 0.0016_{exp} \\pm 0.002_{theor}$, $|V(cb)|_{excl} =\n0.0377 \\pm 0.0016_{exp} \\pm 0.002_{theor}$. The lifetimes of charm and beauty\nhadrons are discussed. The charm lifetimes are predicted/reproduced as well as\ncould be expected. Predictions on B meson lifetimes agree with available data;\n$\\Lambda _b$ baryons are predicted to be shorter lived than B_d mesons by no\nmore than ~ 10% - in marked contrast to present measurements. I evaluate the\nsituation and comment on recent theoretical criticism. The importance of the\nconcepts of global vs. local quark-hadron duality is pointed out.", "category": "hep-ph" }, { "text": "Particle Spectra from the ALCOR Model: We introduce the Transchemistry Model as a dynamical extension of the\nAlgebraic Coalescence Rehadronization (ALCOR) model in describing the\nhadronization of quark matter which is expected to be produced in relativistic\nheavy ion collisions. Results are presented for CERN SPS NA49 Pb+Pb experiment\ncalculating hadron multiplicities and momentum spectra. The freeze-out\nproperties of different hadrons are characterized by similar temperature,\ndensity and flow profiles in cylindrically symmetric geometry.", "category": "hep-ph" }, { "text": "Probe of anomalous neutrino couplings to W and Z in medium energy setup\n of a beta-beam facility: Capability of medium energy setup of a beta beam experiment to probe new\nphysics contributions to neutrino-W and neutrino-Z couplings are investigated.\nWe employ the effective lagrangian approach of Buchmuller and Wyler and obtain\n95% confidence level limits on neutrino couplings to these gauge bosons without\nassuming the flavor universality of the coupling of neutrinos. We show that a\nbeta beam facility can place 3 to 20 times more restrictive limits than present\nones on the deviations from the electron neutrino couplings in the Standard\nModel.", "category": "hep-ph" }, { "text": "Azimuthal spin asymmetries in light-cone constituent quark models: We present results for all leading-twist azimuthal spin asymmetries in\nsemi-inclusive lepton-nucleon deep-inelastic scattering due to T-even\ntransverse-momentum dependent parton distribution functions on the basis of a\nlight-cone constituent quark model. Attention is paid to discuss the range of\napplicability of the model, especially with regard to the scale dependence of\nthe observables and the transverse-momentum dependence of the distributions. We\nfind good agreement with available experimental data and present predictions to\nbe further tested by future CLAS, COMPASS and HERMES data.", "category": "hep-ph" }, { "text": "Non-factorizable corrections to W-pair production: In this paper we study the non-factorizable QED corrections to\nW-pair-mediated (charged-current) four-fermion production in electron-positron\ncollisions. A brief account of the obtained analytical results is given. They\nturn out to be different from the ones published in the literature. For the\nfirst time numerical results are presented, in particular the effects on the W\nline-shape. These effects are of the order of a per cent. Applying the same\nmethods to ZZ- or ZH-mediated four-fermion production, the non-factorizable\n$O(\\alpha)$ corrections to the Z or H line-shape vanish.", "category": "hep-ph" }, { "text": "Search for new physics with neutrinos at Radioactive Ion Beam facilities: We propose applications of Radioactive Ion Beam facilities to investigate\nphysics beyond the Standard Model. In particular, we focus on the possible\nmeasurement of coherent neutrino-nucleus scattering and on a search for sterile\nneutrinos, by means of a low energy beta-beam with a Lorentz boost factor\n$\\gamma \\approx 1$. In the considered setup the collected radioactive ions are\nsent inside a 4$\\pi$ detector. For the first application we provide the number\nof events associated with neutrino-nucleus coherent scattering, when the\ndetector is filled in with a noble liquid. For the sterile search we consider\nthat the spherical detector is filled in with a liquid scintillator, and that\nthe neutrino detection channel is inverse-beta decay. We provide the exclusion\ncurves for the sterile neutrino mixing parameters, based upon the 3+1\nformalism, depending upon the achievable ion intensity. Our results are\nobtained both from total rates, and including spectral information with binning\nin energy and in distance. The proposed experiment represents a possible\nalternative to clarify the current anomalies observed in neutrino experiments.", "category": "hep-ph" }, { "text": "Top condensation as a motivated explanation of the top forward-backward\n asymmetry: Models of top condensation can provide both a compelling solution to the\nhierarchy problem as well as an explanation of why the top-quark mass is large.\nThe spectrum of such models, in particular topcolor-assisted technicolor,\nincludes top-pions, top-rhos and the top-Higgs, all of which can easily have\nlarge top-charm or top-up couplings. Large top-up couplings in particular would\nlead to a top forward-backward asymmetry through $t$-channel exchange, easily\nconsistent with the Tevatron measurements. Intriguingly, there is destructive\ninterference between the top-mesons and the standard model which conspire to\nmake the overall top pair production rate consistent with the standard model.\nThe rate for same-sign top production is also small due to destructive\ninterference between the neutral top-pion and the top-Higgs. Flavor physics is\nunder control because new physics is mostly confined to the top quark. In this\nway, top condensation can explain the asymmetry and be consistent with all\nexperimental bounds. There are many additional signatures of topcolor with\nlarge tu mixing, such as top(s)+jet(s) events, in which a top and a jet\nreconstruct a resonance mass, which make these models easily testable at the\nLHC.", "category": "hep-ph" }, { "text": "Heavy-light meson's physics in Lattice QCD: The possibility of revealing new physics by studying the flavor sector of the\nStandard Model strongly depends upon the accuracy that will be achieved in\n(near) future lattice QCD calculations and, in particular, on heavy-light\nmeson's observables. In turn, handling with heavy-light mesons on the lattice\nis a challenging problem, because of the presence of two largely separated\nenergy scales, and at present it is impossible to extract matrix elements\ninvolving B mesons in external states without recurring to some approximation.\nIn this note I give a fast overview of some of the methods that have been\ndevised to handle such kind of problems, emphasizing those based on finite\nvolume techniques, and briefly discuss some recent results obtained by their\napplication.", "category": "hep-ph" }, { "text": "Feasibility of tau g-2 measurements in ultra-peripheral collisions of\n heavy ions: The anomalous magnetic moment of the tau lepton, a_tau = (g_tau - 2)/2, is a\nsensitive probe of new physics but is extremely difficult to measure precisely\nin contrast to electron and muon moments. The best experimental limits were set\nby the DELPHI collaboration more than 15 years ago in studies of the ditau\nproduction in the e+e -> e+e+tau+tau process. Ultra-peripheral collisions\n(UPCs) of heavy ions at the LHC may provide a unique opportunity to improve the\na_tau constraints in the studies of Pb+Pb -> Pb+Pb+tau+tau process. We review\nrecent proposals to study ditau production via semi-leptonic tau decays in\nPb-Pb UPC with the available ATLAS and CMS data and discuss the feasibility to\nexplore this process down to low transverse momenta of decay leptons with the\nALICE and LHCb experiments.", "category": "hep-ph" }, { "text": "Measuring the Top Yukawa Coupling at 100 TeV: We propose a measurement of the top Yukawa coupling at a 100 TeV hadron\ncollider, based on boosted Higgs and top decays. We find that the top Yukawa\ncoupling can be measured to 1%, with excellent handles for reducing systematic\nand theoretical uncertainties, both from side bands and from\n$t\\bar{t}H/t\\bar{t}Z$ ratios.", "category": "hep-ph" }, { "text": "Remark on approximation in the calculation of the primordial spectrum\n generated during inflation: We re-examine approximations in the analytical calculation of the primordial\nspectrum of cosmological perturbation produced during inflation. Taking two\ninflation models (chaotic inflation and natural inflation) as examples, we\nnumerically verify the accuracy of these approximations.", "category": "hep-ph" }, { "text": "R-charge Kills Monopoles: Large charge density, unlike high temperature, may lead to nonrestoration of\nglobal and gauge symmetries. Supersymmetric GUTs with the appealing scenario of\nunification scale being generated dynamically naturally contain global\ncontinuous $R$ symmetries. We point out that the presence of a large $R$ charge\nin the early Universe can lead to GUT symmetry nonrestoration. This provides a\nsimple way out of the monopole problem.", "category": "hep-ph" }, { "text": "Forward proton scattering in association with muon pair production via\n the photon fusion mechanism at the LHC: Dilepton production in proton-proton collision through $\\gamma\\gamma$-fusion\nwith one proton scattered elastically while the second produces a hadron jet is\nconsidered. Semi-analytical formulas describing the cross section of a muon\npair production are presented.", "category": "hep-ph" }, { "text": "Electroweak phase transition via Dilaton in Two-Time Physics: The Two-time model (2T model) has six dimensions with two dimensions of time,\nhas a Dilaton particle that makes the symmetry breaking differently from the\nStandard Model. Assuming a soft break of $SP(2,R)$ symmetry, the 2T extension\ncan give a suitable picture of the matter-antimatter asymmetry by the\nBaryogenesis scenario. By reducing the 2T metric to the Minkowski metric (1T\nmetric) and using a new form of Dilaton potential, we consider the electroweak\nphase transition picture in the 2T model with the Dilaton as a trigger. Our\nanalysis shows that Electroweak Phase Transition (EWPT) is a first-order phase\ntransition at the $200$ GeV scale, its strength is about $1 - 3.08$ and the\nmass of Dilaton is in the interval $[345,625]$ GeV. Therefore, the 2T-model\nindirectly suggests that extra-dimension can also be a source of EWPT.", "category": "hep-ph" }, { "text": "New algorithm to study the pseudo-Wigner solution of the quark gap\n equation in the framework of the (2+1)-flavor NJL model: In this paper, we study the pseudo-Wigner solution of the quark gap equation\nwith a recently proposed algorithm in the framework of the (2+1)-flavor\nNambu-Jona-Lasinio (NJL) model. We find that for the current quark mass $m_{\\rm\nu,d}=5.5$ MeV and chemical potential $\\mu<\\mu_{\\rm TCP}=272.5$ MeV, the Nambu\nsolution and the positive pseudo-Wigner solution obtained via this algorithm is\nconsistent with the physical solution obtained with the iterative method.\nFurthermore, the algorithm we used can help to illustrate the evolution of the\nsolutions of the gap equation from the chiral limit to non-chiral limit and\ngives a prediction where the crossover line is located in the phase diagram for\n$\\mu<272.5$ MeV. In addition, we also study the chiral susceptibilities as well\nas the loss of solutions for different chemical potentials.", "category": "hep-ph" }, { "text": "FIESTA 3: cluster-parallelizable multiloop numerical calculations in\n physical regions: The goal of this paper is to present a new major release of the program\nFIESTA (Feynman Integral Evaluation by a Sector decomposiTion Approach). This\nversion presents features like cluster-parallelization, new asymptotic\nexpansion algorithms, calculations in physical regions, new\nsector-decomposition strategies, as well as multiple speed, memory, and\nstability improvements.", "category": "hep-ph" }, { "text": "Dynamically generated axial-vector meson resonance in the chiral\n symmetry restored vacuum: We study the modification of the properties of the axial-vector meson,\ndynamically generated through the unitarization procedure, in the vacuum where\nthe chiral symmetry is restored. This is accomplished by scaling the pion decay\nconstant as the chiral order parameter while keeping the other input parameters\nfixed. We find that the mass and width of the axial-vector meson reduce to\nthose of the vector meson, as anticipated by the Weinberg sum rules. The\nfindings are consistent with the results of a recent QCD sum rule calculation,\nwherein the chiral order parameter is expressed through chiral\nsymmetry-breaking four-quark operators, leading to the mass-squared difference\nscaling in proportion to variations in the chiral order parameter. We calculate\nthe scaling behavior for the mass differences obtained from the unitarization\nmethod using both the physical and massless pion masses.", "category": "hep-ph" }, { "text": "Mass effects in muon and semileptonic b -> c decays: Quantum chromodynamics (QCD) effects in the semileptonic decay b -> c l nu\nare evaluated to the second order in the coupling constant, O(alpha_s^2), and\nto several orders in the expansion in quark masses, m_c/m_b. Corrections are\ncalculated for the total decay rate as well as for the first two moments of the\nlepton energy and the hadron system energy distributions. Applied to the muon\ndecay, they decrease its predicted rate by -0.43 ppm.", "category": "hep-ph" }, { "text": "Scale dependence of the q and T parameters of the Tsallis distribution\n in the process of jet fragmentation: The dependence of the $q$ and $T$ parameters of the\nTsallis-distribution-shaped fragmentation function (FF) on the fragmentation\nscale (found to be equal to the jet mass) is calculated via the resummation of\nthe branching process of jet fragmentation in the leading-log appriximation\n(LLA) in the $\\phi^3$ theory. Jet and hadron spectra in electron-positron\n($e^+e^-$) annihilations with 2- and 3-jet final states are calculated using\nvirtual leading partons. It is found that jets, produced earlier in the\nbranching process, are more energetic, and the energy, angle and multiplicity\ndistributions of hadrons stemming from them are broader. It is also found that\nreplacing the LL resummation in the branching process by a single splitting\nprovides good approximation for the jet energy distribution in 2-jet events.\nFurthermore, a micro-canonical statistical event generator is presented for the\nevent-by-event calculation of hadron momenta in $e^+e^-$ annihilations.", "category": "hep-ph" }, { "text": "Unparticle physics in diphoton production at the CERN LHC: We have considered the di-photon production with unparticle at LHC. The\ncontributions of spin-0 and spin-2 unparticle to the di-photon production are\nstudied in the invariant mass and other kinematical distributions, along with\ntheir dependencies on the model dependent parameters. The signal corresponding\nto the unparticle is significant for moderate coupling constant values.", "category": "hep-ph" }, { "text": "CutLHCO: A Consumer-Level Tool for Implementing Generic Collider Data\n Selection Cuts in the Search for New Physics: A new computer program named CutLHCO is introduced, whose function is the\nimplementation of generic data selection cuts on collider event specification\nfiles in the standardized .lhco format. This software is intended to fill an\nopen market niche for a lightweight yet flexible \"consumer-level\" alternative\nto the ROOT data analysis framework. The primary envisioned application is as a\nfilter on output produced by the PGS4 and DELPHES detector simulations, which\nare themselves lightweight alternatives to the GEANT4 based solutions favored\nby the large LHC experiments. All process control instructions are provided via\na compact and powerful card file input syntax that efficiently facilitates the\nreasonable approximation of most event selection strategies and specialized\ndiscovery statistics commonly employed by the CMS and ATLAS collaborations. The\nstructure, function, invocation and usage of the most recent CutLHCO 2.0\nprogram version are documented thoroughly, including a detailed deconstruction\nof several example card file specifications. The associated software is\nsimultaneously being made available for free public download.", "category": "hep-ph" }, { "text": "Extended Dark Matter EFT: Conventional approaches to describe dark matter phenomenology at collider and\n(in)direct detection experiments in the form of dark matter effective field\ntheory or simplified models suffer in general from drawbacks regarding validity\nat high energies and/or generality, limiting their applicability. In order to\navoid these shortcomings, we propose a hybrid framework in the form of an\neffective theory, including, however, both the dark matter states and a\nmediator connecting the former to the Standard Model fields. Since the\nmediation can be realized through rather light new dynamical fields allowing\nfor non-negligible collider signals in missing energy searches, the framework\nremains valid for the phenomenologically interesting parameter region, while\nretaining correlations dictated by gauge symmetry. Moreover, a richer\nnew-physics sector can be consistently included via higher-dimensional\noperators. Interestingly, for fermionic and scalar dark matter with a\n(pseudo-)scalar mediator, the leading effects originate from dimension-five\noperators, allowing to capture them with a rather small set of new couplings.\nWe finally examine the correlations between constraints from reproducing the\ncorrect relic density, direct-detection experiments, and mono-jet and\nHiggs+missing energy signatures at the LHC.", "category": "hep-ph" }, { "text": "CP Violation in the Neutral Higgs Sector of a Non-minimal Supersymmetric\n Standard Model with Multiple Higgs Singlets: The possibility of CP violation is studied in the Higgs sector of a\nsupersymmetric standard model with multiple Higgs singlets. The tree-level\nLagrangian in this model is assumed to conserve the CP symmetry. We find that\nCP violation is viable in this model at the one-loop level, in an explicit way,\nif the radiative corrections from the third generation of quarks and squarks\nare taken into account. In the presence of explicit CP violation, at the\none-loop level, the upper bound on the mass of the lightest neutral Higgs boson\nand the productions of the neutral Higgs bosons via the Higgsstrahlung process\nin high-energy $e^+e^-$ collisions are calculated. We find that the upper bound\non the mass of the lightest neutral Higgs boson increases as the number of\nHiggs singlets increases in a regulated manner. The production cross sections\nof the neutral Higgs bosons also show a reasonable increasing behavior with\nrespect to the number of Higgs singlets.", "category": "hep-ph" }, { "text": "Spontaneous CP Violation in the Next-to-Minimal Supersymmetric Standard\n Model Revisited: We re-examine spontaneous CP violation at the tree level in the context of\nthe next-to-minimal supersymmetric standard model (NMSSM) with two Higgs\ndoublets and a gauge singlet field. We analyse the most general Higgs potential\nwithout a discrete Z_3 symmetry, and derive an upper bound on the mass of the\nlightest neutral Higgs boson consistent with present experimental data. We\ninvestigate, in particular, its dependence on the admixture and CP-violating\nphase of the gauge singlet field, as well as on tan(beta). To assess the\nviability of the spontaneous CP violation scenario, we estimate epsilon_K by\napplying the mass insertion approximation. We find that a non-trivial flavour\nstructure in the soft-breaking A terms is required to account for the observed\nCP violation in the neutral kaon sector. Furthermore, combining the\nminimisation conditions for spontaneous CP violation with the constraints\ncoming from K0-K0bar mixing, we find that the upper bound on the lightest\nHiggs-boson mass becomes stronger. We also point out that the electric dipole\nmoments of electron and neutron are a serious challenge for SUSY models with\nspontaneous CP violation.", "category": "hep-ph" }, { "text": "A role of parton charges and masses in the exclusive photon-photon\n production of meson pairs: The exclusive photon-photon production of the $K$-meson pairs has been\nanalyzed within the partonic model of QCD for the kinematical conditions of\nBELLE experiment. The cross section dependences on partonic masses, charges,\nand a shape of $K$-meson wave function have been studied for the process under\ndiscussion.", "category": "hep-ph" }, { "text": "$\u03bd$ Electroweak Baryogenesis: We investigate if the CP violation necessary for successful electroweak\nbaryogenesis may be sourced by the neutrino Yukawa couplings. In particular, we\nconsider an electroweak scale Seesaw realisation with sizeable Yukawas where\nthe new neutrino singlets form (pseudo)-Dirac pairs. We find that flavour\neffects critically impact the final asymmetry obtained and that, taking them\ninto account, the observed value may be obtained in some regions of the\nparameter space. This source of CP violation naturally avoids the strong\nconstraints from electric dipole moments and links the origin of the baryon\nasymmetry of the Universe with the mechanism underlying neutrino masses.\nInterestingly, the mixing of the active and heavy neutrinos needs to be\nsizeable and could be probed at the LHC or future collider experiments.", "category": "hep-ph" }, { "text": "When does the Schwinger Preheating Occur?: When the inflaton couples to photons and amplifies electric fields, charged\nparticles produced via the Schwinger effect can dominate the universe after\ninflation, which is dubbed as the Schwinger preheating. Using the hydrodynamic\napproach for the Boltzmann equation, we numerically study two cases, the\nStarobinsky inflation model with the kinetic coupling and the anisotropic\ninflation model. The Schwinger preheating is not observed in the latter model\nbut occurs for a sufficiently large inflaton-photon coupling in the first\nmodel. We analytically address its condition and derive a general attractor\nsolution of the electric fields. The occurrence of the Schwinger preheating in\nthe first model is determined by whether the electric fields enter the\nattractor solution during inflation or not.", "category": "hep-ph" }, { "text": "Comparison of improved TMD and CGC frameworks in forward quark dijet\n production: For studying small-$x$ gluon saturation in forward dijet production in\nhigh-energy dilute-dense collisions, the improved TMD (ITMD) factorization\nformula was recently proposed. In the Color Glass Condensate (CGC) framework,\nit represents the leading term of an expansion in inverse powers of the hard\nscale. It contains the leading-twist TMD factorization formula relevant for\nsmall gluon's transverse momentum $k_t$, but also incorporates an all-order\nresummation of kinematical twists, resulting in a proper matching to\nhigh-energy factorization at large $k_t$. In this paper, we evaluate the\naccuracy of the ITMD formula quantitatively, for the case of quark dijet\nproduction in high-energy proton-proton($p+p$) and proton-nucleus ($p+A$)\ncollisions at LHC energies. We do so by comparing the quark-antiquark azimuthal\nangle $\\Delta\\phi$ distribution to that obtained with the CGC formula. For a\ndijet with each quark momentum $p_t$ much larger than the target saturation\nscale, $Q_s$, the ITMD formula is a good approximation to the CGC formula in a\nwide range of azimuthal angle. It becomes less accurate as the jet $p_t$'s are\nlowered, as expected, due to the presence of genuine higher-twists\ncontributions in the CGC framework, which represent multi-body scattering\neffects absent in the ITMD formula. We find that, as the hard jet momenta are\nlowered, the accuracy of ITMD start by deteriorating at small angles, in the\nhigh-energy-factorization regime, while in the TMD regime near\n$\\Delta\\phi=\\pi$, very low values of $p_t$ are needed to see differences\nbetween the CGC and the ITMD formula. In addition, the genuine twists\ncorrections to ITMD become visible for higher values of $p_t$ in $p+A$\ncollisions, compared to $p+p$ collisions, signaling that they are enhanced by\nthe target saturation scale.", "category": "hep-ph" }, { "text": "Transverse momentum spectra of D and B mesons in hadron collisions at\n high energies: Transverse momentum spectra of charmed and beauty mesons produced in\nproton-proton and proton-antiproton collisions at high energies are analyzed\nwithin the modified quark-gluon string model (QGSM) including the internal\nmotion of quarks in colliding hadrons. It is shown that this approach can\ndescribe rather satisfactorily the experimental data at not large values of the\ntransverse momentum where the NLO QCD calculation has a big uncertainty. We\nalso show that using both the QGSM and the NLO QCD one can describe these data\nin a wide region of transverse momenta and give some predictions for the future\nLHC experiments.", "category": "hep-ph" }, { "text": "AROMA 2.2 - A Monte Carlo Generator for Heavy Flavour Events in $ep$\n Collisions: A program to simulate the production of heavy quarks through the boson-gluon\nfusion process in $e^{\\pm}p$ collisions is presented. The full electro\\-weak\nstructure of the electron--gluon interaction is taken into account as well as\nthe masses of the produced heavy quarks. Higher order QCD radiation is treated\nusing initial and final state parton showers, and hadronization is performed\nusing the Lund string model. Physics and programming aspects are described in\nthis manual.", "category": "hep-ph" }, { "text": "The Sigma Meson and Chiral Transition in Hot and Dense Matter: It is pointed out that the hadron spectroscopy should be a study of the\nstructure of the QCD vacuum, low-energy elementary excitations on top of which\nare hadrons. Concentrating on the dynamical breaking of the chiral symmetry in\nthe QCD vacuum, we emphasize the importance to clarify what is going on with\nmesons in the $I=J=0$-channel, i.e., the sigma meson channel, because it is\nconnected to the quantum fluctuations of the chiral order parameter. After\nsummarizing the significance of the sigma meson in QCD and low-energy hadron\nphenomenology, we give a review on some theoretical and experimental effort to\ntry to reveal the possible restoration of chiral symmetry in hot and dense\nnuclear matter including heavy nuclei.", "category": "hep-ph" }, { "text": "Searching for Scalar Ultralight Dark Matter with Optical Fibers: We consider optical fibers as detectors for scalar ultralight dark matter\n(UDM) and propose using a fiber-based interferometer to search for scalar UDM\nwith particle mass in the range $10^{-17} - 10^{-13}$ eV/$c^2$ $\\left(10^{-3}-\n10 \\text{ Hz}\\right)$. Composed of a solid core and a hollow core fiber, the\nproposed detector would be sensitive to relative oscillations in the fibers'\nrefractive indices due to scalar UDM-induced modulations in the fine-structure\nconstant $\\alpha$. We predict that, implementing detector arrays or cryogenic\ncooling, the proposed optical fiber-based scalar UDM search has the potential\nto reach new regions of the parameter space. Such a search would be\nparticularly well-suited to probe for a Solar halo of dark matter with a\nsensitivity exceeding that of previous DM searches over the particle mass range\n$7\\times 10^{-17} - 2\\times 10^{-14}$ eV/$c^2$.", "category": "hep-ph" }, { "text": "Accurate decay-constant ratios $f_{B^*}/f_B$ and $f_{B_s^*}/f_{B_s}$\n from Borel QCD sum rules: We present our analysis of the decay constants of the beauty vector mesons\n$B^*$ and $B^*_s$ within the framework of dispersive sum rules for the\ntwo-point correlator of vector currents in QCD. While the decay constants of\nthe vector mesons $f_{B^*}$ and $f_{B_s^*}$ $-$ similar to the decay constants\nof the pseudoscalar mesons $f_B$ and $f_{B_s}$ $-$ individually have large\nuncertainties induced by theory parameters not known with a satisfactory\nprecision, these uncertainties almost entirely cancel out in the ratios of\nvector over pseudoscalar decay constants. These ratios may be thus predicted\nwith very high accuracy due to the good control over the systematic\nuncertainties of the decay constants gained upon application of our\nhadron-parameter extraction algorithm. Our final results read\n$f_{B^*}/f_B=0.944\\pm0.011_{\\rm OPE}\\pm0.018_{\\rm syst}$ and\n$f_{B_s^*}/f_{B_s}=0.947\\pm0.023_{\\rm OPE}\\pm0.020_{\\rm syst}$. Thus, both\n$f_{B^*}/f_B$ and $f_{B_s^*}/f_{B_s}$ are less than unity at 2.5$\\sigma$ and\n2$\\sigma$ level, respectively.", "category": "hep-ph" }, { "text": "A Parametrization for $K^+\\to \u03c0^+\u03c0^- e^+\u03bd$: We discuss various models and Chiral Perturbation Theory results for the\n$K_{l4}$ form factors $F$ and $G$. We check in how much a simple\nparametrization with a few parameters can be used to extract information from\nexperiment.", "category": "hep-ph" }, { "text": "Electromagnetic Properties of the SU(3) Octet Baryons in the\n semibosonized Nambu--Jona-Lasinio Model: The electromagnetic properties of the SU(3) octet baryons are investigated in\nthe semibosonized SU(3) Nambu--Jona-Lasinio model.The rotational $1/N_c$ and\nstrange quark mass corrections in linear order are taken into account. It turns\nout that the model is in good agreement with the experimental data.", "category": "hep-ph" }, { "text": "Higgsino Dark Matter or Not: Role of Disappearing Track Searches at the\n LHC and Future Colliders: Higgsino in supersymmetric standard models is known to be a promising\ncandidate for dark matter in the Universe. Its phenomenological property is\nstrongly affected by the gaugino fraction in the Higgsino-like state. If this\nis sizable, in other words, if gaugino masses are less than ${\\cal O}(10)$ TeV,\nwe may probe the Higgsino dark matter in future non-accelerator experiments\nsuch as dark matter direct searches and measurements of electric dipole\nmoments. On the other hand, if gauginos are much heavier, then it is hard to\nsearch for Higgsino in these experiments. In this case, due to a lack of\ngaugino components, the mass difference between the neutral and charged\nHiggsinos is uniquely determined by electroweak interactions to be around $350$\nMeV, which makes the heavier charged state rather long-lived, with a decay\nlength of about $1$ cm. In this letter, we argue that a charged particle with a\nflight length of ${\\cal O}(1)$ cm can be probed in disappearing-track searches\nif we require only two hits in the pixel detector. Even in this case, we can\nreduce background events with the help of the displaced-vertex reconstruction\ntechnique. We study the prospects of this search strategy at the LHC and future\ncolliders for the Higgsino dark matter scenario. It is found that an almost\npure Higgsino is indeed within the reach of the future $33$ TeV collider\nexperiments. We then discuss that the interplay among collider and\nnon-accelerator experiments plays a crucial role in testing the Higgsino dark\nmatter scenarios. Our strategy for disappearing-track searches can also enlarge\nthe discovery potential of pure wino dark matter as well as other\nelectroweak-charged dark matter candidates.", "category": "hep-ph" }, { "text": "Is the tri-bimaximal mixing accidental?: The Tri-bimaximal (TBM) mixing is not accidental if structures of the\ncorresponding leptonic mass matrices follow immediately from certain (residual\nor broken) flavor symmetry. We develop a simple formalism which allows one to\nanalyze effects of deviations of the lepton mixing from TBM on structure of the\nneutrino mass matrix and on underlying flavor symmetry. We show that possible\ndeviations from the TBM mixing can lead to strong modifications of the mass\nmatrix and strong violation of the TBM mass relations. As a result, the mass\nmatrix may have an \"anarchical\" structure with random values of elements or it\nmay have some symmetry which differs from the TBM symmetry. Interesting\nexamples include matrices with texture zeros, matrices with certain \"flavor\nalignment\" as well as hierarchical matrices with a two-component structure,\nwhere the dominant and sub-dominant contributions have different symmetries.\nThis opens up new approaches to understand the lepton mixing.", "category": "hep-ph" }, { "text": "Pion mass dependence of the electromagnetic form factors of singly heavy\n baryons: We study the electromagnetic form factors of the lowest-lying singly heavy\nbaryons with spin 1/2 within the framework of the chiral quark-soliton model,\nfocusing on the comparison with recent lattice data. To compare the present\nresults quantitatively with the lattice data, it is essential to treat the pion\nmass as a variable parameter, i.e., to employ the unphysical values of the pion\nmass, which are used in lattice calculations. While the results with the\nphysical value of the pion mass fall off faster than those from the lattice\ncalculations as the momentum transfer increases, the extrapolated results with\nlarger pion masses get closer to the lattice data.", "category": "hep-ph" }, { "text": "Stability constraint for spin equation of state: A generalized Frenkel condition is proposed for use in spin hydrodynamics to\nrelate the spin density and spin polarization (or spin chemical potential)\ntensors. It allows for independent treatment of electric- and magnetic-like\ncomponents of the spin density tensor, which helps to fulfill the stability\nconditions recently derived in the literature. The generalized Frenkel\ncondition extrapolates between the original Frenkel condition, where only the\nmagnetic-like part of the spin tensor is present, and the case where the spin\ndensity tensor is directly proportional to the spin polarization tensor. We\nalso demonstrate that our approach is supported by the result of a microscopic\ncalculation.", "category": "hep-ph" }, { "text": "Searching for supersymmetry in rare B decays: We quantify the ability of B-Factories to observe supersymmetric\ncontributions to the rare decays B -> X_s \\gamma and B -> X_s l+ l-. A global\nfit to the Wilson coefficients which contribute to these decays is performed\nfrom Monte Carlo generated data on B(B -> X_s \\gamma) and the kinematic\ndistributions associated with the final state lepton pair in B -> X_s l+ l-.\nThis fit is then compared to supersymmetric predictions. Evaluation of the\nWilson coefficients is carried out with several different patterns of the\nsuperpartner spectrum. We find that the B-Factories will be able to probe\nregions of the SUSY parameter space not accessible to LEPII, the Tevatron, and\nperhaps the LHC. We also employ the recent NLO calculation of the matrix\nelements for B -> X_s \\gamma and find the bound mH+ > 300 GeV in\ntwo-Higgs-doublet models using present data.", "category": "hep-ph" }, { "text": "Accessing quark helicity in $e^+e^-$ and SIDIS via dihadron correlations: The correlation between the longitudinal polarization of a fragmenting quark\nand the transverse momenta of the produced hadrons was predicted over two\ndecades ago. Nevertheless, experimental searches in the electron-positron\nannihilation process, both through the so-called jet handedness measurements by\nthe {\\tt SLD} Collaboration and more recently via the measurements of the\nazimuthal asymmetry containing the helicity-dependent dihadron fragmentation\nfunction (DiFF) by the $\\textrm{BELLE}$ Collaboration, did not yield a signal.\nWe will first discuss our recent explanation of the zero result at\n$\\textrm{BELLE}$, and the two new methods for accessing the helicity-dependent\nDiFFs both in the electron-positron annihilation experiments, and in the\nsemi-inclusive deep inelastic scattering (SIDIS) experiments with a\nlongitudinally polarized target. We will also for the first time describe yet\nanother, new method for accessing the helicity-dependent DiFFs in SIDIS using\npolarized beam asymmetry. Finally, we will present a new Monte Carlo\ncalculation of the specific Fourier moments of the helicity-dependent DiFF\nentering in to the new asymmetries, performed within the extended quark-jet\nmodel, and compare the results to those for the interference DiFF.", "category": "hep-ph" }, { "text": "Application of the QCD light cone sum rule to tetraquarks: the strong\n vertices $X_bX_b\u03c1$ and $X_cX_c\u03c1$: The full version of QCD light-cone sum rule method is applied to tetraquarks\ncontaining a single heavy $b$ or $c$ quark. To this end, investigations of the\nstrong vertices $X_{b}X_{b}\\rho$ and $X_{c}X_{c}\\rho$ are performed, where\n$X_b=[su][\\bar b\\bar d]$ and $X_c=[su][\\bar c\\bar d]$ are the exotic states\nbuilt of four quarks of different flavors. The strong coupling constants\n$G_{X_{b}X_{b}\\rho}$ and $G_{X_{c}X_{c}\\rho}$ corresponding to these vertices\nare found using the $\\rho$-meson leading and higher-twist distribution\namplitudes. In the calculations $X_{b}$ and $X_{c}$ are treated as scalar bound\nstates of a diquark and antidiquark.", "category": "hep-ph" }, { "text": "Confinement and chiral symmetry crossovers: We study the QCD phase diagram, in particular we study the critical points of\nthe two main QCD phase transitions, confinement and chiral symmetry breaking.\nConfinement drives chiral symmetry breaking, and, due to the finite quark mass,\nat small density both transitions are a crossover, while they are a first or\nsecond order phase transition in large density. We study the QCD phase diagram\nwith a quark potential model including both confinement and chiral symmetry.\nThis formalism, in the Coulomb gauge hamiltonian formalism of QCD, is presently\nthe only one able to microscopically include both a quark-antiquark confining\npotential and a vacuum condensate of quark-antiquark pairs. This model is able\nto address all the excited hadrons, and chiral symmetry breaking, at the same\ntoken. Our order parameters are the Polyakov loop and the quark mass gap. The\nconfining potential is extracted from the Lattice QCD data of the Bielefeld\ngroup. We address how the quark masses affect the critical point location in\nthe phase diagram.", "category": "hep-ph" }, { "text": "Gravitational and higher-order form factors of the pion in chiral quark\n models: The gravitational form factor of the pion is evaluated in two chiral quark\nmodels and confronted to the recent full-QCD lattice data. We find good\nagreement for the case of the Spectral Quark Model, which builds in the\nvector-meson dominance for the charge form factor. We derive a simple relation\nbetween the gravitational and electromagnetic form factors, holding in the\nconsidered quark models in the chiral limit. The relation implies that the\ngravitational mean squared radius is half the electromagnetic one. We also\nanalyze higher-order quark generalized form factors of the pion, related to\nhigher moments in the symmetric Bjorken X-variable of the generalized parton\ndistribution functions, and discuss their perturbative QCD evolution, needed to\nrelate the quark-model predictions to the lattice data. The values of the\nhigher-order quark form factors at t=0, computed on the lattice, also agree\nwith our quark model results within the statistical and method uncertainties.", "category": "hep-ph" }, { "text": "Enhancement of dilepton production rate and electric conductivity around\n QCD critical point: We investigate whether the soft mode that becomes massless at the QCD\ncritical point (CP) causes an enhancement of the dilepton production rate (DPR)\nand the electric conductivity around the CP through the modification of the\nphoton self-energy. The modification is described by the so-called\nAslamazov-Larkin, Maki-Thompson and density of states terms, which have been\ntaken into account in our previous study on the DPR near the\ncolor-superconducting phase transition, with a replacement of the diquark modes\nwith the soft mode of the QCD CP. We show that the coupling of photons with the\nsoft modes brings about an enhancement of the DPR in the low invariant-mass\nregion and the conductivity near the CP, which would be observable in the\nrelativistic heavy-ion collisions.", "category": "hep-ph" }, { "text": "Charged lepton flavor violation searches in the charmonium system: An invited research highlight article on Charged lepton flavor violation\nsearches in the charmonium system.", "category": "hep-ph" }, { "text": "Impact of theoretical uncertainties on model parameter reconstruction\n from GW signals sourced by cosmological phase transitions: Different computational techniques for cosmological phase transition\nparameters can impact the Gravitational Wave (GW) spectra predicted in a given\nparticle physics model. To scrutinize the importance of this effect, we perform\nlarge-scale parameter scans of the dynamical real-singlet extended Standard\nModel using three perturbative approximations for the effective potential: the\n$\\overline{\\rm MS}$ and on-shell schemes at leading order, and\nthree-dimensional thermal effective theory (3D EFT) at next-to-leading order.\nWhile predictions of GW amplitudes are typically unreliable in the absence of\nhigher-order corrections, we show that the reconstructed model parameter spaces\nare robust up to a few percent in uncertainty. While 3D EFT is accurate from\none loop order, theoretical uncertainties of reconstructed model parameters,\nusing four-dimensional standard techniques, remain dominant over the\nexperimental ones even for signals merely strong enough to claim a detection by\nLISA.", "category": "hep-ph" }, { "text": "NLO QCD corrections to pp -> ttbb+X via quark anti-quark annihilation: The process pp -> top anti-top bottom anti-bottom + X represents a very\nimportant background reaction to searches at the LHC, in particular to top\nanti-top H production where the Higgs boson decays into a bottom anti-bottom\npair. A successful analysis of top anti-top H at the LHC requires the knowledge\nof direct top anti-top bottom anti-bottom production at NLO in QCD. We take the\nfirst step in this direction upon calculating the NLO QCD corrections to the\nsubprocess initiated by quark anti-quark annihilation.", "category": "hep-ph" }, { "text": "Hadronization from color interactions: A quark coalescence model is presented based on semi-relativistic molecular\ndynamics with color interactions among quarks taken into account and applied to\n$pp$ collisions to study the effects of this model. A phenomenological\npotential with two tunable parameters is introduced to describe the color\ninteractions between quarks and antiquarks. The interactions drive the process\nof hadronization and finally make them form different color neutral clusters,\nwhich can be identified as hadrons based on some criteria. A Monte Carlo\ngenerator, PYTHIA is used to generate the quarks in the initial state of\nhadronization, and different values of tunable parameters are used to study\ntheir effects on the final state distributions and correlations. Baryon to\nmeson ratios, transverse momentum spectra, pseudorapidity distributions and\nforward-backward multiplicity correlations of hadrons produced in the\nhadronization process from this model with different parameters are compared\nwith those from PYTHIA.", "category": "hep-ph" }, { "text": "The midpoint between dipole and parton showers: We present a new parton-shower algorithm. Borrowing from the basic ideas of\ndipole cascades, the evolution variable is judiciously chosen as the transverse\nmomentum in the soft limit. This leads to a very simple analytic structure of\nthe evolution. A weighting algorithm is implemented, that allows to\nconsistently treat potentially negative values of the splitting functions and\nthe parton distributions. We provide two independent, publicly available\nimplementations for the two event generators Pythia and Sherpa.", "category": "hep-ph" }, { "text": "Phenomenological Approach to Multiple Particle Production: We formulate empirically the rapidity density distribution of produced\nparticles in multiple particle production. The assumed mechanism is that the\nproduced particles are emitted isotropically from several emitting centers,\nlocated on the rapidity axis. The formula includes five adjustable parameters,\nwhich are to be determined by the experimental data of (pseudo-)rapidity\ndensity distributions and transverse momentum distributions at various\nenergies. It is a distinguished difference of the present rapidity density\ndistribution from those of other models that the particle production is\nsuppressed strongly in the forward region. We discuss multiplicity and\ninelasticity at high energies, the pseudo-rapidity density distribution at LHC\nenergy and some speculations, based on the present formulation.", "category": "hep-ph" }, { "text": "Electroweak couplings and LHC constraints on alternative $Z^{\\prime}$\n models in $E_6$: We report the most general expression for the chiral charges of a $Z'$ gauge\nboson coming from an $E_6$ unification model, as a function of the electroweak\nparameters and the charges of the $U(1)$ factors in the chain of subgroups.\nThese charges are valid for an arbitrary Higgs sector and only depend on the\nbranching rules of the $E_6$ fundamental representation and the corresponding\nrules for the fermionic representations of their subgroups. By assuming $E_6$\nunification, the renormalization group equations~(RGE) allow us to calculate\nthe electroweak parameters at low energies for most of the chains of subgroups\nin $E_6$. From RGE and unitary conditions, we show that at low energies there\nmust be a mixing between the gauge boson of the standard model hypercharge and\nthe $Z'$. From this, it is possible to delimit the preferred region in the\nparameter space for a breaking pattern in $E_6$. In general, without\nunification, it is not viable to determine this region; however, for some\nmodels and under certain assumptions, it is possible to limit the corresponding\nparameter space. By using the most recent upper limits on the cross-section of\nextra gauge vector bosons $Z'$ decaying into dileptons from the ATLAS data at\n13~TeV with accumulated luminosities of 36.1~fb$^{-1}$ and 13.3~fb$^{-1}$, we\nreport the 95$\\%$ C.L. lower limits on the $Z'$ mass for the typical $E_6$\nbenchmark models. We also show the contours in the 95\\% C.L. of the $Z'$ mass\nbounds for the entire parameter space of $E_6$.", "category": "hep-ph" }, { "text": "Is Radiative Electroweak Symmetry Breaking Consistent with a 125 GeV\n Higgs Mass?: The mechanism of radiative electroweak symmetry breaking occurs through loop\ncorrections, and unlike conventional symmetry breaking where the Higgs mass is\na parameter, the radiatively-generated Higgs mass is dynamically predicted.\nPade approximations and an averaging method are developed to extend the Higgs\nmass predictions in radiative electroweak symmetry breaking from five- to\nnine-loop order in the scalar sector of the Standard Model, resulting in an\nupper bound on the Higgs mass of 141 GeV. The mass predictions are\nwell-described by a geometric series behaviour, converging to an asymptotic\nHiggs mass of 124 GeV consistent with the recent ATLAS/CMS observations.\nSimilarly, we find that the Higgs self-coupling converges to $\\lambda=0.23$,\nwhich is significantly larger than its conventional symmetry breaking\ncounterpart for a 124 GeV Higgs mass. In addition to this significant\nenhancement of the Higgs self-coupling and $HH\\rightarrow HH$ scattering, we\nfind that Higgs decays to gauge bosons are unaltered and the scattering\nprocesses $W_{L}^{+}W_{L}^{+}\\rightarrow HH$, $Z_{L}Z_{L}\\rightarrow HH$ are\nalso enhanced, providing signals to distinguish conventional and radiative\nelectroweak symmetry breaking mechanisms.", "category": "hep-ph" }, { "text": "Possible Interpretations of $D_{sJ}^+(2632)$ If It Really Exists: We analyze various possible interpretations of the narrow state\n$D_{sJ}^+(2632)$ observed by SELEX Collaboration recently, which lies above\nthreshold and has abnormal decay pattern. These interpretations include: (1)\nseveral versions of tetraquarks; (2) conventional $c\\bar s$ meson such as the\nfirst radial excitation of $D_s(2112)$ with abnormally large SU(3) symmetry\nbreaking; (3) conventional $c\\bar s$ meson with abnormally large $\\eta_1$\ncoupling; (4) heavy hybrid meson. We discuss the physical implications of each\ninterpretation. For example, if the existence of $D_{sJ}^+(2632)$ is confirmed\nas the first radial excitation of $D_s(2112)$ by other experiments, it will be\nhelpful to look for (1) its SU(3) flavor partners $D_{J}^{0,+}(2530)$; (2) its\nB-meson analogues $B_{J}^{0,+}(5840), B_{sJ}^+(5940)$; (3) S-wave two pion\ndecay modes.", "category": "hep-ph" }, { "text": "Mixing at 1-loop in a SU(2)_L gauge theory of weak interactions: Flavor mixing is scrutinized at 1-loop in a SU(2)_L gauge theory of massive\nfermions. The main issue is to cope with kinetic-like, momentum (p^2) dependent\neffective interactions that arise at this order. They spoil the unitarity of\nthe connection between flavor and mass states, which potentially alters the\nstandard Cabibbo-Kobayashi-Maskawa (CKM) phenomenology by giving rise, in\nparticular, to extra flavor changing neutral currents (FCNC). We explore the\nconservative requirement that these should be suppressed, which yields\nrelations between the CKM angles, the fermion and $W$ masses, and a\nrenormalization scale $\\mu$. For two generations, two solutions arise: either\nthe mixing angle of the fermion pair the closer to degeneracy is close to\nmaximal while, inversely, the mass and flavor states of the other pair are\nquasi-aligned, or mixing angles in both sectors are very small. For three\ngenerations, all mixing angles of neutrinos are predicted to be large\n(theta_{23}, close to maximal, is the largest) and the smallness of their mass\ndifferences induces mass-flavor quasi-alignment for all charged leptons. The\nhadronic sector differs in that the top quark is twice as heavy as the W. The\nsituation is, there, bleaker, as all angles come out too large, but,\nnevertheless, encouraging, because theta_{12} decreases as the top mass\nincreases. Whether other super-heavy fermions could drag it down to realistic\nvalues stays an open issue, together with the role of higher order corrections.\nThe same type of counterterms that turned off the 4th order static corrections\nto the quark electric dipole moment are, here too, needed, in particular to\nstabilize quantum corrections to mixing angles.", "category": "hep-ph" }, { "text": "NLO Monte-Carlo approach in 1 or 2 jets Photoproduction: We present a method for calculating the photoproduction of jets at HERA based\non Next to Leading Logarithm QCD calculations. It is implemented in a\nMonte-Carlo generator which allows us to easily compute any infra-red safe\ncross sections for 1 or 2 jet observables using various jet reconstruction\nalgorithms. We focus on the possibility of extracting the gluon contents of the\nphoton and of the proton from present and future H1 and ZEUS data.", "category": "hep-ph" }, { "text": "SU(3) Mixing for Excited Mesons: The SU(3)-flavor symmetry breaking and the quark-antiquark annihilation\nmechanism are taken into account for describing the singlet-octet mixing for\nseveral nonets assigned by Particle Data Group(PDG). This task is approached\nwith the mass matrix formalism.", "category": "hep-ph" }, { "text": "Impact of nonextensivity on the transport coefficients of a magnetized\n hot and dense QCD matter: We have studied the impact of the nonextensivity on the transport\ncoefficients related to charge and heat in thermal QCD. For this purpose, the\nelectrical ($\\sigma_{\\rm el}$), Hall ($\\sigma_{\\rm H}$), thermal ($\\kappa$) and\nHall-type thermal ($\\kappa_{\\rm H}$) conductivities are determined using the\nkinetic theory approach in association with the nonextensive Tsallis\nstatistical mechanism. The effect of nonextensivity is encoded in the\nnonextensive Tsallis distribution function, where the deviation of the\nparameter $q$ from 1 signifies the degree of nonextensivity in the concerned\nsystem. The thermal and electrical conductivities are found to increase with\nthe introduction of nonextensivity, which means that the deviation of the\nmedium from thermal equilibrium enhances both charge and heat transports. With\nthe magnetic field, the deviations of $\\sigma_{\\rm el}$, $\\sigma_{\\rm H}$,\n$\\kappa$ and $\\kappa_{\\rm H}$ from their respective equilibrated values\nincrease, whereas these deviations decrease with the chemical potential. We\nhave also studied how the extent of the nonextensivity modulates the longevity\nof magnetic field. Present work is further extended to the study of some\nobservables associated with the aforesaid transport phenomena, such as the\nKnudsen number and the elliptic flow within the nonextensive Tsallis framework.", "category": "hep-ph" }, { "text": "(beta beta)_{0 nu}-decay: a possible test of the nuclear matrix element\n calculations: The existing calculations of the nuclear matrix elements of the neutrinoless\ndouble beta-decay differ by about a factor three. This uncertainty prevents\nquantative interpretation of the results of experiments searching for this\nprocess. We suggest here that the observation of the neutrinoless double\nbeta-decay of several nuclei in future experiments of could allow to test\ndifferent calculations of the nuclear matrix elements through the direct\ncomparison of them with the experimental data.", "category": "hep-ph" }, { "text": "Status of the NLO Corrections to the Photon Impact Factor: We present the status of the programme of calculating the next-to-leading\norder corrections to the virtual photon impact factor. In particular, we\ndiscuss new results for the transversely polarized photon. We briefly outline\nthe definition of infrared finite terms and the subtraction of the leading\nlogarithmic parts.", "category": "hep-ph" }, { "text": "Decays of the neutral Higgs bosons into SM fermions and gauge bosons in\n the $\\mathcal{CP}$-violating NMSSM: The Next-to-Minimal Supersymmetric Standard Model (NMSSM) offers a rich\nframework embedding physics beyond the Standard Model as well as consistent\ninterpretations of the results about the Higgs signal detected at the LHC. We\ninvestigate the decays of neutral Higgs states into Standard Model (SM)\nfermions and gauge bosons. We perform full one-loop calculations of the decay\nwidths and include leading higher-order QCD corrections. We first discuss the\ntechnical aspects of our approach, before confronting our predictions to those\nof existing public tools, performing a numerical analysis and discussing the\nremaining theoretical uncertainties. In particular, we find that the decay\nwidths of doublet-dominated heavy Higgs bosons into electroweak gauge bosons\nare dominated by the radiative corrections, so that the tree-level\napproximations that are often employed in phenomenological analyses fail.\nFinally, we focus on the phenomenological properties of a mostly singlet-like\nstate with a mass below the one at $125\\,$GeV, a scenario that appears commonly\nwithin the NMSSM. In fact, the possible existence of a singlet-dominated state\nin the mass range around or just below $100\\,$GeV would have interesting\nphenomenological implications. Such a scenario could provide an interpretation\nfor both the $2.3\\sigma$ local excess observed at LEP in the $e^+e^-\\to Z(H\\to\nb\\bar{b})$ searches at $\\sim 98\\,$GeV and for the local excess in the diphoton\nsearches recently reported by CMS in this mass range, while at the same time it\nwould reduce the \"Little Hierarchy\" problem.", "category": "hep-ph" }, { "text": "The renormalization group analysis of the large lepton flavor mixing and\n the neutrino mass: The Superkamiokande experiment suggests the large flavor mixing between nu_mu\nand nu_tau. We show that the mixing angle receives significant corrections from\nthe renormalization group equation (RGE) when both the second and the third\ngeneration neutrino masses are larger than O(0.1eV). This means that the mixing\nangle must be small at the decoupling scale of right-handed neutrinos in the\nmodel containing a sterile neutrino nu_s with the mass spectrum of m_nu_s =\nm_nu_e << m_nu_mu = m_nu_tau.", "category": "hep-ph" }, { "text": "Perturbative QCD description of jet data from LHC Run-I and Tevatron\n Run-II: We present a systematic comparison of jet predictions at the LHC and the\nTevatron, with accuracy up to next-to-next-to-leading order (NNLO). The exact\ncomputation at NNLO is completed for the gluons-only channel, so we compare the\nexact predictions for this channel with an approximate prediction based on\nthreshold resummation, in order to determine the regions where this\napproximation is reliable at NNLO. The kinematic regions used in this study are\nidentical to the experimental setup used by recently published jet data from\nthe ATLAS and CMS experiments at the LHC, and CDF and D0 experiments at the\nTevatron. We study the effect of choosing different renormalisation and\nfactorisation scales for the NNLO exact prediction and as an exercise assess\ntheir impact on a PDF fit including these corrections. Finally we provide\nnumerical values of the NNLO k-factors relevant for the LHC and Tevatron\nexperiments.", "category": "hep-ph" }, { "text": "Decoupling Theoretical Uncertainties from Measurements of the Higgs\n Boson: We develop a technique to present Higgs coupling measurements, which decouple\nthe poorly defined theoretical uncertainties associated to inclusive and\nexclusive cross section predictions. The technique simplifies the combination\nof multiple measurements and can be used in a more general setting. We\nillustrate the approach with toy LHC Higgs coupling measurements and a\ncollection of new physics models.", "category": "hep-ph" }, { "text": "Precision test of a Fermion mass texture: Texture zeros in the quark Yukawa matrices generally lead to precise and\nsimple expressions for CKM matrix elements in terms of ratios of quark masses.\nUsing the new data on $b-$decays we test a particularly promising texture zero\nsolution and show that it is at best approximate. We analyse the approximate\ntexture zero structure and show it is consistent with experiment. We\ninvestigate the implications for the CKM unitarity triangle, measurements at\n$BaBar$ and $BELLE$ as well as for the theories which invoke family symmetries.", "category": "hep-ph" }, { "text": "Uncertainties of predictions from parton distribution functions II: the\n Hessian method: We develop a general method to quantify the uncertainties of parton\ndistribution functions and their physical predictions, with emphasis on\nincorporating all relevant experimental constraints. The method uses the\nHessian formalism to study an effective chi-squared function that quantifies\nthe fit between theory and experiment. Key ingredients are a recently developed\niterative procedure to calculate the Hessian matrix in the difficult global\nanalysis environment, and the use of parameters defined as components along\nappropriately normalized eigenvectors. The result is a set of 2d Eigenvector\nBasis parton distributions (where d=16 is the number of parton parameters) from\nwhich the uncertainty on any physical quantity due to the uncertainty in parton\ndistributions can be calculated. We illustrate the method by applying it to\ncalculate uncertainties of gluon and quark distribution functions, W boson\nrapidity distributions, and the correlation between W and Z production cross\nsections.", "category": "hep-ph" }, { "text": "Thermodynamic inconsistency in quasiparticle model - a revisit: Widely studied quasiparticle models for quark gluon plasma is revisited here\nto understand the statistical mechanics and thermodynamics of the system. We\ninvestigate the statistical mechanics and thermodynamics inconsistencies\ninvolved in these models and their consequences in the observables.\nQuasiparticle model is a phenomenological model with few parameters and by\nadjusting them all models fit the results of lattice gauge simulation of gluon\nplasma \\cite{bo.1}. However, after fixing 2 of the 3 parameters of the model by\nphysical arguments, only one quasiparticle model, which is consistent with both\nstatistical mechanics and thermodynamics, fits the Bielefeld lattice data\n\\cite{bo.1}. The same model also fits the recent lattice results of\nWuppertal-Budapest group \\cite{fo.1}, which deals with precision SU(3)\nthermodynamics for a large temperature range, reasonably well.", "category": "hep-ph" }, { "text": "Unstable Gravitino Dark Matter and Neutrino Flux: The gravitino is a promising supersymmetric dark matter candidate which does\nnot require exact R-parity conservation. In fact, even with some small R-parity\nbreaking, gravitinos are sufficiently long-lived to constitute the dark matter\nof the Universe, while yielding a cosmological scenario consistent with\nprimordial nucleosynthesis and the high reheating temperature required for\nthermal leptogenesis. In this paper, we compute the neutrino flux from direct\ngravitino decay and gauge boson fragmentation in a simple scenario with\nbilinear R-parity breaking. Our choice of parameters is motivated by a proposed\ninterpretation of anomalies in the extragalactic gamma-ray spectrum and the\npositron fraction in terms of gravitino dark matter decay. We find that the\ngenerated neutrino flux is compatible with present measurements. We also\ndiscuss the possibility of detecting these neutrinos in present and future\nexperiments and conclude that it is a challenging task. However, if detected,\nthis distinctive signal might bring significant support to the scenario of\ngravitinos as decaying dark matter.", "category": "hep-ph" }, { "text": "Higgs boson decays into \u03b3\u03b3 and Z\u03b3 in the MSSM and\n BLSSM: We calculate Higgs decay rates into {\\gamma}{\\gamma} and Z{\\gamma} in the\nMinimal Supersymmetric Standard Model (MSSM) and (B-L) Supersymmetric Standard\nModel (BLSSM) by allowing for contributions from light staus and charginos. We\nshow that sizable departures are possible from the SM predictions for the 125\nGeV state and that they are testable during run 2 at the Large Hadron Collider.\nFurthermore, we illustrate how a second light scalar Higgs signal in either or\nboth these decay modes can be accessed at the CERN machine rather promptly\nwithin the BLSSM, a possibility instead precluded to the MSSM owing to the much\nlarger mass of its heavy scalar state.", "category": "hep-ph" }, { "text": "Q-ball Metamorphosis: Flat directions in the minimal supersymmetric standard model are known to\ndeform into non-topological solitons, Q-balls, which generally possess both\nbaryon and lepton asymmetries. We investigate how Q-balls evolve if some of the\nconstituent fields of the flat direction decay into light species. It is found\nthat the Q-balls takes a new configuration whose energy per charge slightly\nincreases due to the decay. Specifically, we show that all the stable Q-balls\neventually transform into pure B-balls via the decay into neutrinos.", "category": "hep-ph" }, { "text": "Nuclear effects in the proton-deuteron Drell-Yan process: We compute the nuclear corrections to the proton-deuteron Drell-Yan cross\nsection for inclusive dilepton production, which, when combined with the\nproton-proton cross section, is used to determine the flavor asymmetry in the\nproton sea, dbar - ubar. In addition to nuclear smearing corrections that are\nknown to be important at large values of the nucleon's parton momentum fraction\nx_N, we also consider dynamical off-shell nucleon corrections associated with\nthe modifications of the bound nucleon structure inside the deuteron, which we\nfind to be significant at intermediate and large x_N values. We also provide\nestimates of the nuclear corrections at kinematics corresponding to existing\nand planned Drell-Yan experiments at Fermilab and J-PARC which aim to determine\nthe dbar/ubar ratio for x < 0.6.", "category": "hep-ph" }, { "text": "A review of neutrino decoupling from the early universe to the current\n universe: We review the distortions of spectra of relic neutrinos due to the\ninteractions with electrons, positrons, and neutrinos in the early universe. We\nsolve integro-differential kinetic equations for the neutrino density matrix,\nincluding vacuum three-flavor neutrino oscillations, oscillations in electron\nand positron background, a collision term and finite temperature corrections to\nelectron mass and electromagnetic plasma up to the next-to-leading order\n$\\mathcal{O}(e^3)$. After that, we estimate the effects of the spectral\ndistortions in neutrino decoupling on the number density and energy density of\nthe Cosmic Neutrino Background (C$\\nu$B) in the current universe, and discuss\nthe implications of these effects on the capture rates in direct detection of\nthe C$\\nu$B on tritium, with emphasis on the PTOLEMY-type experiment. In\naddition, we find a precise value of the effective number of neutrinos, $N_{\\rm\neff}=3.044$. However, QED corrections to weak interaction rates at order\n$\\mathcal{O}(e^2 G_F^2)$ and forward scattering of neutrinos via their\nself-interactions have not been precisely taken into account in the whole\nliterature so far. Recent studies suggest that these neglections might induce\nuncertainties of $\\pm(10^{-3} - 10^{-4})$ in $N_{\\rm eff}$.", "category": "hep-ph" }, { "text": "An extended Higgs sector for neutrino mass, dark matter and baryon\n asymmetry: In this talk, we discuss a TeV scale model which would explain neutrino\noscillation, dark matter, and baryon asymmetry of the Universe simultaneously\nby the dynamics of the extended Higgs sector and TeV-scale right-handed\nneutrinos. By the imposed exact $Z_2$ symmetry, tiny neutrino masses are\ngenerated at the three loop level, and the stability of the dark matter\ncandidate, an additional singlet scalar field, is guaranteed. The extra Higgs\ndoublet is introduced not only for neutrino masses but also for successful\nelectroweak baryogenesis. The model provides various discriminative predictions\nin Higgs phenomenology, which can be tested at the Large Hadron Collider and\nthe International Linear Collider.", "category": "hep-ph" }, { "text": "3-3-1 exotic quark search at CERN LEPII-LHC: The 3-3-1 electroweak model is the simplest chiral extension of the standard\nmodel which predicts single and double charged bileptons and exotic quarks\ncarrying -4/3 and 5/3 units of the positron charge. In this paper we study the\npossibilities of the production and decay of one of these exotic quarks at CERN\nLEPII-LHC collider. For typical vector bilepton, exotic quark masses and mixing\nangles we obtained between 20 and 750 events per year. Angular distributions\nare also presented.", "category": "hep-ph" }, { "text": "Theoretical investigations on the Y(4260) being an hybrid meson: The new recently experiments at the B-factories yield a renewed interest in\nthe charm and charmonium spectroscopy. New intriguing states have been\nobserved, which appear to be non-conventional mesons, such as X(3862) and\nY(4260) and request more theoretical investigations. We will explore the\npossibility for the Y(4260) to be a c-cbar-g hybrid meson. Using the\nquark-gluon constituent model, we exclude its existence as QE-hybrid meson, and\nas mixing of c-cbar-g hybrid with conventional c-cbar meson. We find the only\ninterpretation as GE-hybrid, decaying in D_(1)-Dbar channels. Then more\nexperimental studies are needed to confirm the existence of this resonance and\nto give its properties.", "category": "hep-ph" }, { "text": "The Heavy Quark Expansion for the Charm Quark: We show that one can re-arrange the Heavy Quark Expansion for inclusive weak\ndecays of charmed hadrons in such a way that the resulting expansion is an\nexpansion in $\\Lambda_{\\rm QCD} / m_c$ and $\\alpha_s (m_c)$ with order-one\ncoefficients. Unlike in the case of the bottom quark, the leading term includes\nnot only the contribution of the free-quark decay, but also a tower of terms\nrelated to matrix elements of four quark operators.", "category": "hep-ph" }, { "text": "Reach of the CERN LHC for the Minimal Anomaly-Mediated SUSY Breaking\n Model: We examine the reach of the CERN LHC pp collider for supersymmetric models\nwhere the dominant contribution to soft SUSY breaking parameters arises from\nthe superconformal anomaly. In the simplest viable anomaly mediated SUSY\nbreaking (AMSB) model, tachyonic slepton squared masses are made positive by\nadding a universal contribution m_0^2 to all scalars. We use the event\ngenerator ISAJET to generate AMSB signal events as a function of model\nparameter space. Assuming an integrated luminosity of 10 fb-1, the LHC can\nreach to values of $m_{\\tg}\\sim 2.3$ TeV for low values of $m_0$, where the\ndilepton plus jets plus E_T(missing) channel offers the best reach. For large\n$m_0$, the best signature is typically 0 or 1 isolated lepton plus jets plus\nE_T(missing); in this case the reach is typically diminished to values of\n$m_{\\tg}\\sim 1.3$ TeV. The presence of terminating tracks in a subset of signal\nevents could serve to verify the presence of a long lived lightest chargino\nwhich is generic in the minimal AMSB model.", "category": "hep-ph" }, { "text": "One-loop Weak Dipole Form Factors and Weak Dipole Moments of Heavy\n Fermions: The one-loop weak-magnetic and weak-electric dipole form factors of heavy\nfermions in a generic model are derived. Numerical predictions for the $\\tau$\nlepton and $b$ quark Weak Anomalous Magnetic and Electric Dipole Moments (AWMDM\nand WEDM) in the SM and MSSM are reviewed. The MSSM contribution to the $\\tau$\n($b$) AWMDM could be, in the high $\\tan\\beta$ scenario, four (thirty) times\nlarger than the Electroweak SM one, but still a factor five below the QCD\ncontribution (in the $b$ case). More interesting is the CP-odd sector where the\ncontribution to the $\\tau$ ($b$) WEDM in the MSSM could be up to twelve orders\nof magnitude larger than in the SM.", "category": "hep-ph" }, { "text": "Gauge Dependence of Lower Bounds on the Higgs Mass Derived from\n Electroweak Vacuum Stability Constraints: We examine the gauge dependence of lower bounds on the Higgs mass obtained\nfrom the requirement that the electroweak vacuum be the global minimum of the\neffective potential. We study a simple model, the spontaneously-broken Abelian\nHiggs model coupled to a chiral quark doublet in a two-parameter gauge and\ndemonstrate that the lower bounds on the Higgs mass obtained in this model are\ndependent on the choice of gauge parameters. We discuss the significance of\nthis result for calculations in the Standard Model.", "category": "hep-ph" }, { "text": "Zee and Zee-Babu mechanisms in the minimal 331 model: We show that the minimal 3-3-1 model cannot accommodate the neutrino masses\nat tree level using present experimental data. Nevertheless, a modified Zee and\nthe Zee-Babu mechanisms for generating neutrino masses at 1-loop and 2-loop,\nrespectively, are automatically implemented in the minimal 3-3-1 model, without\nintroducing new degrees of freedom to the model. We also present a systematic\nmethod for finding solutions to the leptonic sector masses and mixing. As a\ncase study, we accommodate the charged and neutral leptons masses and the PMNS\nmatrix in the 1-loop modified Zee mechanism contained in the minimal 3-3-1\nmodel.", "category": "hep-ph" }, { "text": "Troubles with the Minimal SU(5) Supergravity Model: We show that within the framework of the minimal $SU(5)$ supergravity model,\nradiatively-induced electroweak symmetry breaking and presently available\nexperimental lower bounds on nucleon decay, impose severe constraints on the\navailable parameter space of the model which correspond to fine-tuning of the\nmodel parameters of over two orders of magnitude. Furthermore, a\nstraightforward calculation of the cosmic relic density of neutralinos ($\\chi$)\ngives $\\Omega_\\chi h^2\\gg1$ for most of the allowed parameter space in this\nmodel, although small regions may still be cosmologically acceptable. We\nfinally discuss how the {\\it no-scale flipped $SU(5)$ supergravity model}\navoids naturally the above troubles and thus constitutes a good candidate for\nthe low-energy effective supergravity model.", "category": "hep-ph" }, { "text": "Bounds on heavy Majorana neutrinos in type-I seesaw and implications for\n collider searches: The neutrino masses and flavor mixings, which are missing in the Standard\nModel (SM), can be naturally incorporated in the type-I seesaw extension of the\nSM with heavy Majorana neutrinos being singlet under the SM gauge group. If the\nheavy Majorana neutrinos are around the electroweak scale and their mixings\nwith the SM neutrinos are sizable, they can be produced at high energy\ncolliders, leaving characteristic signatures with lepton-number violations.\nEmploying the general parametrization for the neutrino Dirac mass matrix in the\nminimal seesaw scenario, we perform a parameter scan and identify allowed\nregions to satisfy a variety of experimental constraints from the neutrino\noscillation data, the electroweak precision measurements and the lepton-flavor\nviolating processes. We find that the resultant mixing parameters between the\nheavy neutrinos and the SM neutrinos are more severely constrained than those\nobtained from the current search for heavy Majorana neutrinos at the LHC. Such\nparameter regions can be explored at the High-Luminosity LHC and a 100 TeV\npp-collider in the future.", "category": "hep-ph" }, { "text": "Energy Momentum Tensor Correlators in Improved Holographic QCD: In this thesis, we study the physics of the quark gluon plasma (QGP) using\nholographic methods borrowed from string theory. We start our discussion by\nmotivating the use of such machinery, explaining how recent experimental\nresults from the LHC and RHIC colliders suggests that the created QGP should be\ndescribed as a strongly coupled liquid with small but nonvanishing bulk and\nshear viscosities. We argue that holographic dualities are a very efficient\nframework for studying transport properties in such a medium.\n Next, we introduce the underlying physics behind all holographic dualities,\nthe AdS/CFT correspondence, and then motivate the necessity of implementing\nconformal invariance breaking in them. After this, we present the\nphenomenologically most successful holographic model of the strong interactions\n- Improved Holographic QCD (IHQCD).\n Working within IHQCD, we next move on to calculate energy momentum tensor\ncorrelators in the bulk and shear channels of large-Nc Yang-Mills theory. In\nthe shear channel, we confront our results with those derived in strongly\ncoupled N=4 Super Yang-Mills theory as well as weakly interacting ordinary\nYang-Mills theory. Close to the critical temperature of the deconfinement\ntransition, we observe significant effects of conformal invariance breaking. In\nthe bulk channel, where the conformal result is trivial, we make comparisons\nwith both perturbative and lattice QCD. We observe that lattice data seem to\nfavor our holographic prediction over the perturbative one over a wide range of\ntemperatures.", "category": "hep-ph" }, { "text": "A comprehensive study on the semileptonic decay of heavy flavor mesons: The semileptonic decay of heavy flavor mesons offers a clean environment for\nextraction of the Cabibbo-Kobayashi-Maskawa (CKM) matrix elements, which\ndescribes the CP-violating and flavor changing process in the Standard Model.\nThe involved form factors where the dynamical information is encoded play an\nessential role in achieving any conclusive statement. That is, the knowledge of\nthe form factors should be under good control, requiring one to examine more\nobservables in addition to the branching fraction. In this paper, we provide\nthe mean value and the $q^2$-dependent shape for further observables\n[differential decay distribution ($d\\Gamma/dq^2$), forward-backward asymmetry\n($\\mathcal{A}_{FB}^l$), longitudinal ($P_L^l$) and transverse ($P_T^l$)\npolarization of a charged lepton, longitudinal polarization of a vector meson\nin the final state ($F_L^l(V)$), leptonic convexity parameter ($C_F^l$), and\ntrigonometric moments ($W_i^l$) in the decay of $D_{(s)}$ and $B_{(s)}$ to $P/V\nl^+ \\nu_l$ ($l=e$, $\\mu$ or $\\tau$)], based on the predictions of the relevant\nform factors from the covariant light-front quark model. $P$ and $V$ denote the\npseudoscalar and vector meson, respectively. As a comparison, we find a good\nagreement with the results from the covariant confining quark model and the\nrelativistic quark model in the literature. As it has been observed that the\n$P_L^l$ and $F_L^l(V)$ are crucial quantities to discriminate various New\nPhysics models, the reexamination of these observables from a different method\nis also essential and necessary.", "category": "hep-ph" }, { "text": "The tau lepton Monte Carlo Event Generation -- imprinting New Physics\n models with exotic scalar or vector states into simulation samples: The Monte Carlo for lepton pair production andtau decays consist of KKMC for\nlepton pair production, tauola for tau lepton decays and photos for radiative\ncorrections in decays.\n An effort for adaptation of the system for precision data being collected at\nthe Belle II experiment included simulation of additional light lepton pairs.\nExtension to processes where lepton pair is produced through narrow resonances,\nlike dark photon or dark scalar phi resonances, was straight forward.\n Modified programs versions are available in stand-alone format from gitlab\nrepository or through the basf2 system of Belle II software. It was explained\nrecently during the International Workshop on Tau Lepton Physics September,\n2021, Bloomington IN. Now we concentrate on simulations for phi resonance, a\nhypothetical object which could be responsible for anomalous moment g-2 in\nZ-\\tau-\\tau interactions through virtual contributions.", "category": "hep-ph" }, { "text": "Possible Suppression of Resonant Signals for Split-UED by Mixing at the\n LHC?: The mixing of the imaginary parts of the transition amplitudes of nearby\nresonances via the breakdown of the Breit-Wigner approximation has been shown\nto lead to potentially large modifications in the signal rates for new physics\nat colliders. In the case of suppression, this effect may be significant enough\nto lead to some new physics signatures being initially missed in searches at,\ne.g., the LHC. Here we explore the influence of this `width mixing' on the\nproduction of the nearly degenerate, level-2 Kaluza-Klein (KK) neutral gauge\nbosons present in Split-UED. We demonstrate that in this particular case large\ncross section modifications in the resonance region are necessarily absent and\nexplain why this is so based on the group theoretical structure of the SM.", "category": "hep-ph" }, { "text": "Electrodynamics with Lorentz-violating operators of arbitrary dimension: The behavior of photons in the presence of Lorentz and CPT violation is\nstudied. Allowing for operators of arbitrary mass dimension, we classify all\ngauge-invariant Lorentz- and CPT-violating terms in the quadratic Lagrange\ndensity associated with the effective photon propagator. The covariant\ndispersion relation is obtained, and conditions for birefringence are\ndiscussed. We provide a complete characterization of the coefficients for\nLorentz violation for all mass dimensions via a decomposition using\nspin-weighted spherical harmonics. The resulting nine independent sets of\nspherical coefficients control birefringence, dispersion, and anisotropy. We\ndiscuss the restriction of the general theory to various special models,\nincluding among others the minimal Standard-Model Extension, the isotropic\nlimit, the case of vacuum propagation, the nonbirefringent limit, and the\nvacuum-orthogonal model. The transformation of the spherical coefficients for\nLorentz violation between the laboratory frame and the standard Sun-centered\nframe is provided. We apply the results to various astrophysical observations\nand laboratory experiments. Astrophysical searches of relevance include studies\nof birefringence and of dispersion. We use polarimetric and dispersive data\nfrom gamma-ray bursts to set constraints on coefficients for Lorentz violation\ninvolving operators of dimensions four through nine, and we describe the mixing\nof polarizations induced by Lorentz and CPT violation in the cosmic-microwave\nbackground. Laboratory searches of interest include cavity experiments. We\npresent the theory for searches with cavities, derive the experiment-dependent\nfactors for coefficients in the vacuum-orthogonal model, and predict the\ncorresponding frequency shift for a circular-cylindrical cavity.", "category": "hep-ph" }, { "text": "Annihilating Asymmetric Dark Matter: The relic abundance of particle and antiparticle dark matter (DM) need not be\nvastly different in thermal asymmetric dark matter (ADM) models. By considering\nthe effect of a primordial asymmetry on the thermal Boltzmann evolution of\ncoupled DM and anti-DM, we derive the requisite annihilation cross section.\nThis is used in conjunction with CMB and Fermi-LAT gamma-ray data to impose a\nlimit on the number density of anti-DM particles surviving thermal freeze-out.\nWhen the extended gamma-ray emission from the Galactic Center is reanalyzed in\na thermal ADM framework, we find that annihilation into $\\tau$ leptons prefer\nanti-DM number densities 1-4$\\%$ that of DM while the $b$-quark channel prefers\n50-100$\\%$.", "category": "hep-ph" }, { "text": "Anti-B --> X(s) gamma in two universal extra dimensions: We calculate the leading order corrections to the anti-B --> X(s) gamma decay\nin the standard model with two large flat universal extra dimensions. We find\nthat the contributions involving the exchange of Kaluza-Klein modes of the\nphysical scalar field a^+-_(kl) depend logarithmically on the ultraviolet\ncut-off scale Lambda. We emphasize that all flavor-changing neutral current\ntransitions suffer from this problem. Although the ultraviolet sensitivity\nweakens the lower bound on the inverse compactification radius 1/R that follows\nfrom anti-B --> X(s) gamma, the constraint remains stronger than any other\navailable direct measurement. After performing a careful study of the potential\nimpact of cut-off and higher-order effects, we find 1/R > 650 GeV at 95%\nconfidence level if errors are combined in quadrature. Our limit is at variance\nwith the parameter region 1/R <~ 600 GeV preferred by dark matter constraints.", "category": "hep-ph" }, { "text": "Large mixing, family structure, and dominant block in the neutrino mass\n matrix: A possible connection between the flavour structure of the charged fermions\nand the large $\\nu_\\mu-\\nu_\\tau$ mixing motivates an ansatz for the neutrino\nmass matrix with a dominant block. We distinguish between a general form and\nthe specific forms of the ansatz, and concentrate on the cases of\nphenomenological interest. The general form can incorporate an observable\namount of CP violation in the leptonic sector. Only specific forms can\nincorporate the Mikheyev-Smirnov-Wolfenstein solutions for solar neutrinos,\nwith small or large mixing angles. Other specific variants explain the Los\nAlamos neutrino anomaly, or provide a two-neutrino hot dark matter component.", "category": "hep-ph" }, { "text": "Semi-inclusive production of spin-3/2 hadrons in deep inelastic\n scattering: We investigate the production of spin-3/2 hadrons in semi-inclusive deep\ninelastic lepton-nucleon scatterings. The complete differential cross section\nis derived through the kinematic analysis and expressed in terms of 288\nstructure functions, corresponding to all polarization configurations and\nazimuthal modulations. For an unpolarized lepton beam, half of the 192\nstructure functions have nonzero leading order contributions in the parton\nmodel, among which 42 are from rank-3 tensor polarized fragmentation functions\nof the hadron. For a polarized lepton beam, one third of the 96 structure\nfunctions contribute at the leading order and 14 of them are from rank-3 tensor\npolarized fragmentation functions. In addition to the formalism, we perform a\nmodel estimation of the spin transfer to a $S_{hLLL}$ polarized hadron and\nsizable asymmetry is expected. Therefore, these newly defined observables for\nthe production of a spin-3/2 hadron in semi-inclusive deep inelastic scattering\nprocess can be explored in future experiments to understand nucleon spin\nstructures and spin-dependent fragmentation functions.", "category": "hep-ph" }, { "text": "A sum rule for elastic scattering: A sum rule is derived for elastic scattering of hadrons at high energies\nwhich is in good agreement with experimental data on $p\\bar{p}$ available upto\nthe maximum energy $\\sqrt{s} = 2 TeV$. Physically, our sum rule reflects the\nway unitarity correlates and limits how large the elastic amplitude can be as a\nfunction of energy to how fast it decreases as a function of the momentum\ntransfer. The universality of our result is justified through our earlier\nresult on equipartition of quark and glue momenta obtained from the virial\ntheorem for massless quarks and the Wilson conjecture", "category": "hep-ph" }, { "text": "Are CP Violating Effects in the Standard Model Really Tiny?: We derive an effective action of the bosonic sector of the Standard Model by\nintegrating out the fermionic degrees of freedom in the worldline approach. The\nCP violation due to the complex phase in the CKM matrix gives rise to\nCP-violating operators in the effective action. We calculate the prefactor of\nthe appropriate next-to-leading order operators and give general estimates of\nCP violation in the bosonic sector of the Standard Model. In particular, we\nshow that the effective CP violation for weak gauge fields is not suppressed by\nthe Yukawa couplings of the light quarks and is much larger than the bound\ngiven by the Jarlskog determinant.", "category": "hep-ph" }, { "text": "Diagnosis of Supersymmetry Breaking Mediation Schemes by Mass\n Reconstruction at the LHC: If supersymmetry is discovered at the LHC, the next question will be the\ndetermination of the underlying model. While this may be challenging or even\nintractable, a more optimistic question is whether we can understand the main\ncontours of any particular paradigm of the mediation of supersymmetry breaking.\nThe determination of superpartner masses through endpoint measurements of\nkinematic observables arising from cascade decays is a powerful diagnostic\ntool. In particular, the determination of the gaugino sector has the potential\nto discriminate between certain mediation schemes (not all schemes, and not\nbetween different UV realizations of a given scheme). We reconstruct gaugino\nmasses, choosing a model where anomaly contributions to supersymmetry breaking\nare important (KKLT compactification), and find the gaugino unification scale.\nMoreover, reconstruction of other superpartner masses allows us to solve for\nthe parameters defining the UV model. The analysis is performed in the stop and\nstau coannihilation regions where the lightest neutralinos are mainly gauginos,\nto additionally satisfy dark matter constraints. We thus develop observables to\ndetermine stau and stop masses to verify that the coannihilation mechanism is\nindeed operational, and solve for the relic density.", "category": "hep-ph" }, { "text": "Electron Mass Operator in a Strong Magnetic Field and Dynamical Chiral\n Symmetry Breaking: The electron mass operator in a strong magnetic field is calculated. The\ncontribution of higher Landau levels of virtual electrons, along with the\nground Landau level, is shown to be essential in the leading log approximation.\nThe effect of the electron dynamical mass generation by a magnetic field is\ninvestigated. In a model with N charged fermions, it is shown that some\ncritical number N_{cr} exists for any value of the electromagnetic coupling\nconstant alpha, such that the fermion dynamical mass is generated with a\ndoublet splitting for N < N_{cr}, and the dynamical mass does not arise at all\nfor N > N_{cr}, thus leaving the chiral symmetry unbroken.", "category": "hep-ph" }, { "text": "Three-Loop Effective Potential of O(N) $\u03c6^4$ Theory: The three-loop effective potential of the massless O(N) $\\phi^4$ theory is\ncalculated analytically using techniques of dimensional regularization. We see\na complete agreement between our result and Jackiw's result obtained only up to\ntwo-loop order using a different regularization (cutoff regularization) method,\nbut the same renormalization conditions. For an easy check of the mutual\ncancellation of all the dangerous pole terms in each loop order, we give the\n$\\epsilon$-expanded loop integrals in full detail.", "category": "hep-ph" }, { "text": "Towards a consistent AdS/QCD dictionary: This note focuses on the large-N behaviour of the Hard Wall model of QCD and\nclarifies the AdS/QCD dictionary formulated on the basis of the AdS/CFT\ncorrespondence. It is shown how short-distance studies performed in the\nframework of the AdS/QCD Soft Wall model allow one to determine unambiguously\nthe chiral symmetry breaking function in the Hard Wall model. Especially, the\ndifferent forms of the field/operator prescription are emphasized. The large-N\nbehaviour of the Hard Wall model is then checked considering the vector and\ngravitational form factors of the pion in the chiral limit.", "category": "hep-ph" }, { "text": "Inclusive hadronic distributions at small x: After giving their general expressions valid at all x, double differential\n1-particle inclusive distribution inside a quark and a gluon jet produced in a\nhard process, together with the inclusive kt distribution, are given at small x\nin the Modified Leading Logarithmic Approximation (MLLA), as functions of the\ntransverse momentum kt of the outgoing hadron.", "category": "hep-ph" }, { "text": "Matching of Fracture Functions for SIDIS in Target Fragmentation Region: In the target fragmentation region of Semi-Inclusive Deep Inelastic\nScattering, the diffractively produced hadron has small transverse momentum. If\nit is at order of $\\Lambda_{QCD}$, it prevents to make predictions with the\nstandard collinear factorization. However, in this case, differential\ncross-sections can be predicted by the factorization with fracture functions,\ndiffractive parton distributions. If the transverse momentum is much larger\nthan $\\Lambda_{QCD}$ but much smaller than $Q$ which is the virtuality of the\nvirtual photon, both factorizations apply. In this case, fracture functions can\nbe factorized with collinear parton distributions and fragmentation functions.\nWe study the factorization up to twist-3 level and obtain gauge invariant\nresults. They will be helpful for modeling fracture functions and useful for\nresummation of large logarithm of the transverse momentum appearing in\ncollinear factorization.", "category": "hep-ph" }, { "text": "Isolating a light Higgs boson from the di-photon background at the LHC: We compute the QCD corrections to the gluon fusion subprocess gg to gamma\ngamma, which forms an important component of the background to the search for a\nlight Higgs boson at the LHC. We study the dependence of the improved pp to\ngamma gamma X background calculation on the factorization and renormalization\nscales, on various choices for photon isolation cuts, and on the rapidities of\nthe photons. We also investigate ways to enhance the statistical significance\nof the Higgs signal in the di-photon channel.", "category": "hep-ph" }, { "text": "SMEFT interpretation of $\u0394$F = 2 transitions: A model-independent anatomy of $\\Delta F= 2$ transitions in the context of\nthe Weak Effective Theory (WET) below the electroweak scale (EW) and the\nStandard Model Effective Field Theory (SMEFT) above the EW scale is discussed.\nTwo master formulae for the BSM contribution of the mixing amplitude $M_{12}$,\nin terms of Wilson coefficients are presented. The coefficients entering these\nformulae contain all the information below the EW scale and the NP scale\n$\\Lambda$, respectively. The renormalization group evolution from the top-quark\nYukawa coupling has the largest impact on the result. The obtained expressions\ndepend on whether the down-basis or the up-basis for SMEFT operators is\nconsidered.", "category": "hep-ph" }, { "text": "Confinement of Fermions in Tachyon Matter at Finite Temperature: We study a phenomenological model that mimics the characteristics of QCD\ntheory at finite temperature. The model involves fermions coupled with a\nmodified Abelian gauge field in a tachyon matter. It reproduces some important\nQCD features such as, confinement, deconfinement, chiral symmetry and\nquark-gluon-plasma (QGP) phase transitions. The study may shed light on both\nlight and heavy quark potentials and their string tensions. Flux-tube and\nCornell potentials are developed depending on the regime under consideration.\nOther confining properties such as scalar glueball mass, gluon mass,\nglueball-meson mixing states, gluon and chiral condensates are exploited as\nwell. The study is focused on two possible regimes, the ultraviolet (UV) and\nthe infrared (IR) regimes.", "category": "hep-ph" }, { "text": "Light $q\\bar{q}$ Resonances: Spectrum and Decays: I give a brief introduction to light $q\\bar{q}$ resonances. The properties of\n$q\\bar{q}$ states are discussed in the context of the constituent quark model,\nincluding predictions for mass and partial decay widths. Problems and puzzles\nin the meson spectrum are pointed out with an emphasis on how an 8+ GeV photon\nbeam can address these. I also point out some areas where I believe theoretical\nstudy would be useful.", "category": "hep-ph" }, { "text": "Chiral density waves in quarkyonic matter: We study the phase diagram of strongly interacting matter including the\ninhomogeneous phase of Chiral Density Waves (CDW) within the Polyakov loop\nextended Nambu-Jona-Lasinio (PNJL) model. We discuss the phase structure taking\ninto account density and flavour dependence of the Polyakov loop potential\nparameter and temperature dependence of the four-point coupling constant of the\nNJL model. It is shown that the CDW phase exists and that can be interpreted as\na special realisation of quarkyonic matter. This fact is of particular interest\nbecause the existence of homogeneous quarkyonic matter is strongly constrained.\nThis also indicates that the study of inhomogeneous phases at finite\ntemperatures and baryon densities are of special importance.", "category": "hep-ph" }, { "text": "Light Scalars and the KOTO Anomaly: The KOTO experiment recently presented a significant excess of events in\ntheir search for the rare SM process $K_L \\to \\pi^0\\nu\\bar{\\nu}$, well above\nboth Standard Model signal and background predictions. We show that this excess\nmay be due to weakly-coupled scalars that are produced from Kaon decays and\nescape KOTO undetected. We study two concrete realizations, the minimal Higgs\nportal and a hadrophilic scalar model, and demonstrate that they can explain\nthe observed events while satisfying bounds from other flavor and beam-dump\nexperiments. Hadronic beam-dump experiments provide particularly interesting\nconstraints on these types of models, and we discuss in detail the normally\nunderestimated uncertainties associated with them. The simplicity of the models\nwhich can explain the excess, and their possible relations with interesting UV\nconstructions, provides strong theoretical motivation for a new physics\ninterpretation of the KOTO data.", "category": "hep-ph" }, { "text": "Studying the Higgs Potential at the e+e- Linear Collider: The determination of the shape of the Higgs potential is needed to complete\nthe investigation of the Higgs profile and to obtain a direct experimental\nproof of the mechanism of electro-weak symmetry breaking. This can be achieved,\nat a linear collider, by determining the Higgs triple self-coupling g_HHH in\nthe processes e+e--> HHZ and HHnunu and, possibly, the quartic coupling. This\npaper summarises the results of a study of the expected accuracies on the\ndetermination of g_HHH at a TeV-class LC and at a multi-TeV LC. The statistical\ndilution arising from contributions not sensitive to the triple Higgs vertex,\ncan be reduced by means of variables sensitive to the kinematics and the spin\nproperties of the reactions.", "category": "hep-ph" }, { "text": "An analysis of f_0-sigma mixing in light cone QCD sum rules: We investigate f_0-sigma mixing in the framework of light cone QCD sum rules\nand by employing the experimental results about the decay widths and the masses\nof these scalar mesons we estimate the scalar mixing angle by using sigma meson\ndata and f_0 meson data. The two values we thus obtain of the scalar mixing\nangle are not entirely consistent with each other, possibly indicating that the\nstructure of these mesons cannot be simple quark-antiquark states.", "category": "hep-ph" }, { "text": "Pinching phenomenon: Central feature in out of equilibrium thermal field\n theories: We continue to study out of equilibrium TFT with switching on the interaction\noccurring at finite time. We exploit the concept of projected function (PF) and\nWigner transform of projected function (WTPF). WTPF's are bare propagators,\none-loop self-energies, retarded and advanced components of the resummed\npropagator. Among WTPF's convolution product is very simple, one does not need\ngradient expansion. However, WTPF's are completely determined by their infinite\ntime limit and, thus, cannot be the carriers of relaxation phenomena.\nFurthermore, we observe that the functions capable of carrying relaxation\nphenomena (non-WTPF) emerge in the mixed (\"ill-defined\") products of retarded\nand advanced propagators and self-energies. In particular, only non-WTPF's\ncontribute to time variation of equal-time Green functions (particle number,\netc.); contributions from WTPF will be constant in time. As these are generated\nin mixed products, the pinching phenomenon is being promoted from an obstacle\nto the central feature of out of equilibrium TFT. We analyze the pinching\nphenomenon. In the case of naive pinching we reproduce known results. In\nSchwinger-Dyson equations the Keldysh component of self-energy is well defined\neven for multiple self-energy insertion contributions. We calaculate explicitly\nsingle self-energy contribution to Keldysh component of propagator which\ngenerates nontrivial time dependence. For photon production from QCD plasma\n(finite-lifetime effect) our approximate analytic results agree with the\nresults by S. -Y. Wang and D. Boyanovsky obtained within dynamical\nrenormalisation group approach.", "category": "hep-ph" }, { "text": "Charged Lepton Flavor Violation at the High-Energy Colliders: Neutrino\n Mass Relevant Particles: We summarize the potential charged lepton flavor violation (LFV) from\nneutrino mass relevant models, for instance the seesaw mechanisms. In\nparticular, we study, in a model-dependent way, the LFV signals at the\nhigh-energy hadron and lepton colliders originating from the beyond standard\nmodel (BSM) neutral scalar $H$, doubly charged scalar $H^{\\pm\\pm}$, heavy\nneutrino $N$, heavy $W_R$ boson, and the $Z'$ boson. For the neutral scalar,\ndoubly charged scalar and $Z'$ boson, the LFV signals originate from the\n(effective) LFV couplings of these particles to the charged leptons, while for\nthe heavy neutrino $N$ and $W_R$ boson, the LFV effects are from flavor mixing\nin the neutrino sector. We consider current limits on these BSM particles and\nestimate their prospects at future high-energy hadron and lepton colliders.", "category": "hep-ph" }, { "text": "Sea contribution to the charge radii and quadrupole moment of\n $J^P=\\frac{1}{2}^+, \\frac{3}{2}^+$ baryons: An operator formalism is used on the wavefunction of baryons to compute their\ncharge radii and quadrupole moments. Total anti-symmetric wavefunction in spin,\ncolor and flavor space is framed for $J^P=\\frac{1}{2}^+$ nucleons and\n$J^P=\\frac{3}{2}^+$ hyperons. To understand the importance of sea, statistical\nmodel is used in conjugation with the detailed balance principle. Within the\nstatistical approach, the importance of sea with quarks and gluons are studied\nusing the relevant probabilities that are associated with spin, flavor, and\ncolor space. The present work also focuses on individual contributions of\nvalence and sea which contains terms of scalar, vector and tensor sea. The\nobtained results are in agreement with available theories and few experimental\noutcomes. Our computed results may provide important information for upcoming\nexperimental findings.", "category": "hep-ph" }, { "text": "The renormalization group and quark number fluctuations in the Polyakov\n loop extended quark-meson model at finite baryon density: Thermodynamics and the phase structure of the Polyakov loop-extended two\nflavors chiral quark--meson (PQM) model is explored beyond the mean-field\napproximation. The analysis of the PQM model is based on the functional\nrenormalization group (FRG) method. We formulate and solve the renormalization\ngroup flow equation for the scale-dependent thermodynamic potential in the\npresence of the gluonic background field at finite temperature and density. We\ndetermine the phase diagram of the PQM model in the FRG approach and discuss\nits modification in comparison with the one obtained under the mean-field\napproximation. We focus on properties of the net-quark number density\nfluctuations as well as their higher moments and discuss the influence of\nnon-perturbative effects on their properties near the chiral crossover\ntransition. We show, that with an increasing net-quark number density the\nhigher order moments exhibit a peculiar structure near the phase transition. We\nalso consider ratios of different moments of the net-quark number density and\ndiscuss their role as probes of deconfinement and chiral phase transitions.", "category": "hep-ph" }, { "text": "Singlet scalars as Higgs imposters at the Large Hadron Collider: An electroweak singlet scalar can couple to pairs of vector bosons through\nloop-induced dimension five operators. Compared to a Standard Model Higgs\nboson, the singlet decay widths in the diphotons and Z gamma channels are\ngenerically enhanced, while decays into massive final states like WW and ZZ are\nkinematically disfavored. The overall event rates into gamma gamma and Z gamma\ncan exceed the Standard Model expectations by orders of magnitude. Such a\nsinglet may appear as a resonant signal in the gamma gamma and Z gamma\nchannels, even with a mass above the WW kinematic threshold.", "category": "hep-ph" }, { "text": "A road to an elementary particle physics model with no Higgs -- II: This is the second of two companion papers in which we continue developing\nthe construction of an elementary particle model with no Higgs. Here we show\nthat the recently identified non-perturbative field-theoretical feature,\nalternative to the Higgs mechanism and capable of giving masses to quarks,\nTera-quarks and $W$, can also provide mass to leptons and Tera-leptons when the\nmodel is extended to include, besides strong, Tera-strong and weak\ninteractions, also hypercharge. In the present approach elementary fermion\nmasses are not free parameters but are determined by the dynamics of the\ntheory. We derive parametric formulae for elementary particle masses from which\nwe can ``predict'' the order of magnitude of the scale of the new\nTera-interaction and get crude numerical estimates for mass ratios in fair\nagreement with phenomenology. The interest of considering elementary particle\nmodels endowed with this kind of non-perturbative mass generation mechanism is\nthat they allow solving some of the conceptual problems of the present\nformulation of the Standard Model, namely origin of the electroweak scale and\nnaturalness.", "category": "hep-ph" }, { "text": "J/P=1/2+, J/P=3/2+ masses in statistical model: The mass formulae for the baryon octet and decuplet are calculated. These\nformulae are function of constituent quark masses and spin spin interaction\nterms for the quarks inside the baryons. The coefficients in the mass formulae\nis estimated by the statistical model for J/P=1/2+, J/P=3/2+, incorporating the\ncontributions from \\sea\" containing uu; dd; ss pairs and gluons . The measured\nmasses are presented and found to be matching good with some of the\nexperimental and theoretical data.", "category": "hep-ph" }, { "text": "Leptoquark effects on $b \\to s \u03bd\\bar\u03bd$ and $B \\to K l^+ l^-$\n decay processes: We study the rare semileptonic decays of $B$ mesons induced by $b \\to s \\nu\n\\bar{\\nu}$ as well as $b \\to s l^+ l^-$ transitions in the scalar leptoquark\nmodel where the leptoquarks transform as $(3,2,7/6)$ and $(3,2,1/6)$ under the\nstandard model gauge group. The leptoquark parameter space is constrained using\nthe most recent experimental results on ${\\rm Br}(B_s \\rightarrow \\mu^+ \\mu^-)$\nand ${\\rm Br}(B_d \\to X_s \\mu^+ \\mu^-)$ processes. Considering only the baryon\nnumber conserving leptoquark interactions, we estimate the branching ratios for\nthe exclusive $\\bar{B} \\rightarrow \\bar{K}^{(*)} \\nu \\bar{\\nu}$ and inclusive\n$B \\rightarrow X_s \\nu \\bar{\\nu}$ decay processes by using the constraint\nparameters. We also obtain the low recoil (large lepton invariant mass, i.e.,\n$q^2 \\sim m^2_b$) predictions for the angular distribution of $\\bar B\n\\rightarrow \\bar{K} l^+ l^-$ process and several other observables including\nthe flat term and lepton flavour non-universality factor in this model.", "category": "hep-ph" }, { "text": "Drell-Yan hadron tensor: contour gauge and gluon propagator: We consider the gauge invariant Drell-Yan hadron tensor which includes the\nstandard and non-standard diagram contributions. The non-standard diagram\ncontribution is appeared owing to the complexity of the twist three\n$B^V(x_1,x_2)$-function where the gluon pole manifests. We use the contour\ngauge conception which allows us to fix easily the spurious uncertainties in\nthe gluon propagator. The contour gauge condition is generated by the\ncorresponding Wilson lines in both the standard and non-standard diagrams. We\ndemonstrate the substantial role of the non-standard diagram for forming of the\nrelevant contour in the Wilson path-ordered exponential that leads to the\nspurious singularity fixing.", "category": "hep-ph" }, { "text": "Shift Symmetry and Higgs Inflation in Supergravity with Observable\n Gravitational Waves: We demonstrate how to realize within supergravity a novel chaotic-type\ninflationary scenario driven by the radial parts of a conjugate pair of Higgs\nsuperfields causing the spontaneous breaking of a grand unified gauge symmetry\nat a scale assuming the value of the supersymmetric grand unification scale.\nThe superpotential is uniquely determined at the renormalizable level by the\ngauge symmetry and a continuous R symmetry. We select two types of Kahler\npotentials, which respect these symmetries as well as an approximate shift\nsymmetry. In particular, they include in a logarithm a dominant shift-symmetric\nterm proportional to a parameter c- together with a small term violating this\nsymmetry and characterized by a parameter c+. In both cases, imposing a lower\nbound on c-, inflation can be attained with subplanckian values of the original\ninflaton, while the corresponding effective theory respects perturbative\nunitarity for r+-=c+/c-<1. These inflationary models do not lead to\noverproduction of cosmic defects, are largely independent of the one-loop\nradiative corrections and accommodate, for natural values of r+-, observable\ngravitational waves consistently with all the current observational data. The\ninflaton mass is mostly confined in the range (3.7-8.1)x10^10 GeV.", "category": "hep-ph" }, { "text": "Global analysis of the Sivers functions at NLO+NNLL in QCD: We perform global fit to the quark Sivers function within the transverse\nmomentum dependent (TMD) factorization formalism in QCD. We simultaneously fit\nSivers asymmetry data from Semi-Inclusive Deep Inelastic Scattering (SIDIS) at\nCOMPASS, HERMES, and JLab, from Drell-Yan lepton pair production at COMPASS,\nand from $W/Z$ boson at RHIC. This extraction is performed at next-to-leading\norder (NLO) and next-to-next-to leading logarithmic (NNLL) accuracy. We find\nexcellent agreement between our extracted asymmetry and the experimental data\nfor SIDIS and Drell-Yan lepton pair production, while tension arises when\ntrying to describe the spin asymmetries of $W/Z$ bosons at RHIC. We carefully\nassess the situation, and we study in details the impact of the RHIC data and\ntheir implications through different ways of performing the fit. In addition,\nwe find that the quality of the description of $W/Z$ vector boson asymmetry\ndata could be strongly sensitive to the DGLAP evolution of Qiu-Sterman\nfunction, besides the usual TMD evolution. We present discussion on this and\nthe implications for measurements of the transverse-spin asymmetries at the\nfuture Electron Ion Collider.", "category": "hep-ph" }, { "text": "Insights from the Interplay of K -> pi nu anti-nu and epsilon_K on the\n New Physics Flavour Structure: In certain new physics (NP) models, such as the Littlest Higgs model with\nT-parity, a strict correlation between the K_L -> pi0 nu anti-nu and K+ -> pi+\nnu anti-nu branching ratios has been observed, allowing essentially only for\ntwo branches of possible points, while in other NP frameworks, such as the\ngeneral MSSM or warped extra dimensional models, no visible correlation\nappears. We analyse the origin of the correlation in question and show it to be\na direct consequence of the stringent experimental constraint on epsilon_K,\nprovided that the NP enters with comparable strength and a universal weak phase\nin both Delta S = 2 and Delta S = 1 transitions. This happens in many NP\nscenarios with either only SM operators, or where the NP induces exclusively\nright-handed currents while the left-right Delta S = 2 operators are absent. On\nthe other hand, if the NP phases in Delta S = 2 and Delta S = 1 processes are\nuncorrelated, epsilon_K has no power to put constraints on the K -> pi nu\nanti-nu system. The latter appears in particular in those NP models where K^0 -\nanti-K^0 mixing receives contributions from the chirally enhanced left-right\noperators. We discuss the stability of the correlation in question against\nsmall deviations from the assumption of universal Delta S = 2 and Delta S = 1\nweak phases, and in the presence of non-negligible NP contributions to\nepsilon_K.", "category": "hep-ph" }, { "text": "Masses and Mixing of $c q \\bar{q} \\bar{q}$ Tetraquarks Using\n Glozman-Riska Hyperfine Interaction: In this paper we perform a detailed study of the masses and mixing of the\nsingle charmed scalar tetraquarks: $c q \\bar{q} \\bar{q}$. We also give a\nsystematic analysis of these tetraquark states by weight diagrams, quantum\nnumbers and flavor wave functions. Tetraquark masses are calculated using four\ndifferent fits. The following SU(3)$_\\mathrm{F}$ representations are discussed:\n$\\bar{15}_\\mathrm{S}$, $\\bar{3}_\\mathrm{S}$, $6_\\mathrm{A}$ and\n$\\bar{3}_\\mathrm{A}$. We use the flavor-spin Glozman-Riska interaction\nHamiltonian with SU(3) flavor symmetry breaking. There are 27 different\ntetraquarks composed of a charm quark $c$ and of the three light flavors $u, d,\ns$: 11 cryptoexotic (3 D$_\\mathrm{s}^{+}$, 4 D$^{+}$, 4 D$^{0}$) and 16\nexplicit exotic states. We discuss D$_\\mathrm{s}$ and its isospin partners in\nthe same multiplet, as well as all the other four-quark states. Some explicit\nexotic states appear in the spectrum with the same masses as\nD$_\\mathrm{s}^{+}$(2632) in $\\bar{15}_\\mathrm{S}$ and with the same masses as\nD$_\\mathrm{s}^{+}$(2317) in $6_\\mathrm{A}$ representation, which confirm the\ntetraquark nature of these states.", "category": "hep-ph" }, { "text": "Non-Abelian Discrete Flavor Symmetries from Magnetized/Intersecting\n Brane Models: We study non-abelian discrete flavor symmetries, which can appear in\nmagnetized brane models. For example, $D_4$, $\\Delta(27)$ and $\\Delta(54)$ can\nappear and matter fields with several representations can appear. We also study\nthe orbifold background, where non-abelian flavor symmetries are broken in a\ncertain way.", "category": "hep-ph" }, { "text": "Super-leading logarithms in non-global observables in QCD: Colour basis\n independent calculation: In a previous paper we reported the discovery of super-leading logarithmic\nterms in a non-global QCD observable. In this short update we recalculate the\nfirst super-leading logarithmic contribution to the 'gaps between jets'\ncross-section using a colour basis independent notation. This sheds light on\nthe structure and origin of the super-leading terms and allows them to be\ncalculated for gluon scattering processes for the first time.", "category": "hep-ph" }, { "text": "Precise predictions for mt, Vcb and tan: The fermion mass and mixing angle predictions of a recently proposed\nframework are investigated for large b and $\\tau$ Yukawa couplings. A new\nallowed region of parameters is found for this large $\\tan \\beta$ case. The two\npredictions which are substantially altered, $m_t$ and $\\tan \\beta$, are\ndisplayed, including the dependence on the inputs $|V_{cb}|$, $m_c$, $m_b$ and\n$\\alpha_s$. A simple restriction on this framework yields an additional\nprediction, for $|V_{cb}|$. If the b,t, and $\\tau$ Yukawas are equal at the GUT\nscale then $|\\Vcb|$ is predicted and the top quark mass is constrained to lie\nin the range $\\mt = 179. \\pm 4.$ GeV.", "category": "hep-ph" }, { "text": "Light axial-vector tetraquark state candidate: $a_1(1420)$: In this article, we study the axial-vector tetraquark state and\ntwo-quark-tetraquark mixed state consist of light quarks using the QCD sum\nrules. The present predictions disfavor assigning the $a_1(1420)$ as the\naxial-vector tetraquark state with $J^{PC}=1^{++}$, while support assigning the\n$a_1(1420)$ as the axial-vector two-quark-tetraquark mixed state.", "category": "hep-ph" }, { "text": "Energy dependence of underlying-event observables from RHIC to LHC\n energies: A study of the charged-particle density (number density) in the transverse\nregion of the di-hadron correlations exploiting the existing pp and p$\\bar{\\rm\np}$ data from RHIC to LHC energies is reported. This region has contributions\nfrom the Underlying Event (UE) as well as from Initial- and Final-State\nRadiation (ISR-FSR). Based on the data, a two-component model is built. This\nhas the functional form $\\propto s^{\\alpha}+\\beta\\log(s)$, where the\nlogarithmic (($\\beta = 0.140 \\pm 0.007$)) and the power-law ($\\alpha = 0.270\n\\pm 0.005$) terms describe the components more sensitive to the ISR-FSR and UE\ncontributions, respectively. The model describes the data from RHIC to LHC\nenergies, the extrapolation to higher energies indicates that at around\n$\\sqrt{s} \\approx 100$\\,TeV the number density associated to UE will match that\nfrom ISR-FSR. Although this behaviour is not predicted by PYTHIA~8.244, the\npower-law behaviour of the UE contribution is consistent with the energy\ndependence of the parameter that regulates Multiparton Interactions. Using\nsimulations, KNO-like scaling properties of the multiplicity distributions in\nthe regions sensitive to either UE or ISR-FSR are also discussed. The results\npresented here can be helpful to constrain QCD-inspired Monte Carlo models at\nthe Future Circular Collider energies, as well as to characterize the UE-based\nevent classifiers which are currently used at the LHC.", "category": "hep-ph" }, { "text": "Study of Single W production in e-gamma collisions through the decay\n lepton spectrum to probe gamma-WW couplings: We investigate the effect of anomalous gamma-W-W couplings in e-gamma --> nu\nW through the angular and energy spectrum of the secondary leptons. Within the\nnarrow-width approximation, a semi-analytical study of the secondary lepton\nenergy-angle double distribution is considered. Utility of observables derived\nfrom this is demonstrated by considering the anomalous coupling,\ndelta-kappa-gamma. Results of our investigation for typical ILC machine\nconsidered at Ecm = 300-1000 GeV re-affirms potential of this collider as a\nprecision machine.", "category": "hep-ph" }, { "text": "Spectrum-doubled Heavy Vector Bosons at the LHC: We study a simple effective field theory incorporating six heavy vector\nbosons together with the standard-model field content. The new particles\npreserve custodial symmetry as well as an approximate left-right parity\nsymmetry. The enhanced symmetry of the model allows it to satisfy precision\nelectroweak constraints and bounds from Higgs physics in a regime where all the\ncouplings are perturbative and where the amount of fine-tuning is comparable to\nthat in the standard model itself.\n We find that the model could explain the recently observed excesses in\ndi-boson processes at invariant mass close to 2 TeV from LHC Run 1 for a range\nof allowed parameter space. The masses of all the particles differ by no more\nthan roughly 10%. In a portion of the allowed parameter space only one of the\nnew particles has a production cross section large enough to be detectable with\nthe energy and luminosity of Run 1, both via its decay to WZ and to Wh, while\nthe others have suppressed production rates. The model can be tested at the\nhigher-energy and higher-luminosity run of the LHC even for an overall scale of\nthe new particles higher than 3 TeV.", "category": "hep-ph" }, { "text": "Affleck-Dine dynamics and the dark sector of pangenesis: Pangenesis is the mechanism for jointly producing the visible and dark matter\nasymmetries via Affleck-Dine dynamics in a baryon-symmetric universe. The\nbaryon-symmetric feature means that the dark asymmetry cancels the visible\nbaryon asymmetry and thus enforces a tight relationship between the visible and\ndark matter number densities. The purpose of this paper is to analyse the\ngeneral dynamics of this scenario in more detail and to construct specific\nmodels. After reviewing the simple symmetry structure that underpins all\nbaryon-symmetric models, we turn to a detailed analysis of the required\nAffleck-Dine dynamics. Both gravity-mediated and gauge-mediated supersymmetry\nbreaking are considered, with the messenger scale left arbitrary in the latter,\nand the viable regions of parameter space are determined. In the gauge-mediated\ncase where gravitinos are light and stable, the regime where they constitute a\nsmall fraction of the dark matter density is identified. We discuss the\nformation of Q-balls, and delineate various regimes in the parameter space of\nthe Affleck-Dine potential with respect to their stability or lifetime and\ntheir decay modes. We outline the regions in which Q-ball formation and decay\nis consistent with successful pangenesis. Examples of viable dark sectors are\npresented, and constraints are derived from big bang nucleosynthesis, large\nscale structure formation and the Bullet cluster. Collider signatures and\nimplications for direct dark matter detection experiments are briefly\ndiscussed. The following would constitute evidence for pangenesis:\nsupersymmetry, GeV-scale dark matter mass(es) and a Z' boson with a significant\ninvisible width into the dark sector.", "category": "hep-ph" }, { "text": "A New Hypothesis on the Origin of the Three Generations: We suggest that the Standard Model may undergo a supercritical transition\nnear the Landau scale, where the U(1) gauge boson couples to the left and right\nhanded states of any given fermion with different charges. This scenario\nnaturally gives rise to three generations of fermion, corresponding to the\nthree critical scales for the right-right, right-left and left-left fermion\ninteractions going supercritical, as well as CP violation in the quark sector.", "category": "hep-ph" }, { "text": "Lepton flavor violation beyond the MSSM: Most extensions of the Standard Model lepton sector predict large lepton\nflavor violating rates. Given the promising experimental perspectives for\nlepton flavor violation in the next few years, this generic expectation might\noffer a powerful indirect probe to look for new physics. In this review we will\ncover several aspects of lepton flavor violation in supersymmetric models\nbeyond the Minimal Supersymmetric Standard Model. In particular, we will\nconcentrate on three different scenarios: high-scale and low-scale seesaw\nmodels as well as models with R-parity violation. We will see that in some\ncases the LFV phenomenology can have characteristic features for specific\nscenarios, implying that dedicated studies must be performed in order to\ncorrectly understand the phenomenology in non-minimal supersymmetric models.", "category": "hep-ph" }, { "text": "Domain walls in the Two-Higgs-Doublet Model and their charge and\n CP-violating interactions with Standard Model fermions: Discrete symmetries play an important role in several extensions of the\nStandard Model (SM) of particle physics. For instance, in order to avoid flavor\nchanging neutral currents, a discrete $Z_2$ symmetry is imposed on the\nTwo-Higgs-Doublet Model (2HDM). This can lead to the formation of domain walls\n(DW) as the $Z_2$ symmetry gets spontaneously broken during electroweak\nsymmetry breaking in the early universe and domain walls form between regions\nwhose vacua are related by the discrete symmetry. Due to this simultaneous\nspontaneous breaking of both the discrete symmetry and the electroweak\nsymmetry, the vacuum manifold consists of two disconnected 3-spheres. Such a\nnon-trivial disconnected vacuum manifold leads to several choices for the vacua\nat two adjacent regions, in contrast to models where only the discrete symmetry\ngets spontaneously broken and the vacuum manifold consists of several\ndisconnected points. Due to this, we end up with several classes of DW\nsolutions having different properties localized inside the wall, such as charge\nand/or CP violating vacua. We discuss the properties of these different classes\nof DW solutions as well as the interaction of SM fermions with such topological\ndefects leading to different exotic phenomena such as, for example, the top\nquark being transmitted or reflected off the wall as a bottom quark.", "category": "hep-ph" }, { "text": "A new approach for calculating the Nambu-Gorkov propagator in color\n superconductivity theory: In this article, we propose a new approach to calculate the Nambu-Gorkov\npropagator intuitively with some linear algebra techniques in presence of the\nscalar diquark condensates. With the help of energy projective operators, we\ncan obtain relatively simple expressions for the quark propagators, which\ngreatly facilitate the calculations in solving the Schwinger-Dyson equation to\nobtain the gap parameters.", "category": "hep-ph" }, { "text": "More on Parametrization Relevant to Describe Violation of CP, T and CPT\n Symmetries in the $K^0-\\bar{K^0}$ System: To study violation of CP, T and/or CPT symmetries in the $K^0-\\bar{K^0}$\nsystems, one has to parametrize the relevant mixing parameters and decay\namplitudes in such a way that each parameter represents violation of these\nsymmetries in a well-defined way. Parametrization is of course not unique and\nis always subject to phase ambiguities. We discuss these problems with freedom\nassociated with rephasing of final (or intermediate) as well as initial states\ntaken into account. We present a fully rephasing-invariant parametrization and\na particular rephasing-dependent parametrization, and give a couple of comments\nrelated to these and other possible parametrizations.", "category": "hep-ph" }, { "text": "Leading Order Calculation of Electric Conductivity in Hot Quantum\n Electrodynamics from Diagrammatic Methods: Using diagrammatic methods, we show how the Ward identity can be used to\nconstrain the ladder kernel in transport coefficient calculations. More\nspecifically, we use the Ward identity to determine the necessary diagrams that\nmust be resummed using an integral equation. One of our main results is an\nequation relating the kernel of the integral equation with functional\nderivatives of the full self-energy; it is similar to what is obtained with 2PI\neffective action methods. However, since we use the Ward identity as our\nstarting point, gauge invariance is preserved. Using power counting arguments,\nwe also show which self-energies must be included in the resummation at leading\norder, including 2 to 2 scatterings and 1 to 2 collinear scatterings with the\nLPM effect. We show that our quantum field theory result is equivalent to the\none of Arnold, Moore and Yaffe obtained using effective kinetic theory. In this\npaper we restrict our discussion to electrical conductivity in hot QED, but our\nmethod can in principle be generalized to other transport coefficients and\nother theories.", "category": "hep-ph" }, { "text": "Gluon correlations from a Glasma flux-tube model compared to measured\n hadron correlations on transverse momentum $\\bf (p_t,p_t)$ and angular\n differences $\\bf (\u03b7_\u0394,\u03c6_\u0394)$: A Glasma flux-tube model has been proposed to explain strong elongation on\npseudorapidity $\\eta$ of the same-side 2D peak in minimum-bias angular\ncorrelations from $\\sqrt{s_{NN}} = 200$ GeV \\auau collisions. The same-side\npeak or \"soft ridge\" is said to arise from coupling of flux tubes to radial\nflow. Gluons radiated transversely from flux tubes are boosted by radial flow\nto form a narrow structure or ridge on azimuth. In this study we test the\nconjecture by comparing predictions for particle production, spectra and\ncorrelations from the Glasma model and conventional fragmentation processes\nwith measurements. We conclude that the Glasma model is contradicted by\nmeasured hadron yields, spectra and correlations, whereas a two-component model\nof hadron production, including minimum-bias parton fragmentation, provides a\nquantitative description of most data, although $\\eta$ elongation remains\nunexplained.", "category": "hep-ph" }, { "text": "Unitary and Analytic Models in Particle Physics Phenomenology: After two decades of a development of the unitary and analytic models of the\nelectromagnetic structure of hadrons and nuclei their main principles are\nbriefly formulated, then a general scheme of their applications to the\nelectromagnetic, weak and strong interaction processes are traced out and\nfinally, some results of their successful applications are reviewed.", "category": "hep-ph" }, { "text": "Thoughts about the utility of perturbative QCD in the cores of neutron\n stars: In this contribution, I discuss the utility that perturbative QCD offers in\nstudying the matter in the cores of neutron stars. I discuss the reasons why\nperturbative QCD can constrain the equation of state at densities far below the\ndensities where we can perform controlled calculations. I discuss how\nperturbative QCD can inform nuclear modelling of neutron stars and how it\ninfluences equation-of-state inference. And finally, I discuss the implications\nto the QCD phase diagram and argue that interesting features in the equation of\nstate revealed by the QCD input may be used to argue for the existence of\nquark-matter cores in most massive neutron stars.", "category": "hep-ph" }, { "text": "Dark matter astrometry at underground detectors with multiscatter events: We show that current and imminent underground detectors are capable of\nprecision astrometry of dark matter. First we show that galactic dark matter\nvelocity distributions can be obtained from reconstructed tracks of dark matter\nscattering on multiple nuclei during transit; using the liquid scintillator\nneutrino detector SNO+ as an example, we find that the dark matter velocity\nvector can be reconstructed event-by-event with such a small uncertainty, that\nthe precision of dark matter astrometry will be limited mainly by statistics.\nWe then determine the number of dark matter events required to determine the\ndispersion speed, escape speed, and velocity anisotropies of the local dark\nmatter halo, and also find that with as few as $\\mathcal{O}(10)$ events, dark\nmatter signals may be discriminated from potential backgrounds arising as\npower-law distributions. Finally, we discuss the prospects of dark matter\nastrometry at other liquid scintillator detectors, dark matter experiments, and\nthe recently proposed MATHUSLA detector.", "category": "hep-ph" }, { "text": "Improving the J/psi Production Baseline at RHIC and the LHC: We assess the theoretical uncertainties on the inclusive J/psi production\ncross section in the Color Evaporation Model (CEM) using values for the charm\nquark mass, renormalization and factorization scales obtained from a fit to the\ncharm production data. We use our new results to provide improved baseline\ncomparison calculations at RHIC and the LHC. We also study cold matter effects\non J/psi production at leading relative to next-to-leading order in the CEM\nwithin this approach.", "category": "hep-ph" }, { "text": "What Can We Learn About Leptoquarks At LEP200?: We investigate the discovery potential for first generation leptoquarks at\nthe LEP200 $e^+e^-$ collider. We consider direct leptoquark searches using\nsingle leptoquark production via resolved photon contributions which offers a\nmuch higher kinematic limit than the more commonly considered leptoquark pair\nproduction process. Depending on the coupling strength of the leptoquark,\nsearch limits can be obtained to within a few GeV of $\\sqrt{s}$. We also\nconsider LQ limits that can be obtained from t-channel interferences effects in\n$e^+e^- \\to hadrons$.", "category": "hep-ph" }, { "text": "The predictions of the charm structure function exponents behaviour at\n low x in deep inelastic scattering: We use the hard (Lipatov) pomeron for the low-x gluon distribution and\nprovide a compact formula for the ratio $R^{c} =F_{L}^{c}/F_{2}^{c}$ that is\nuseful to extract the charm structure function from the reduced charm\ncross-section, in particular at DESY HERA. Our results show that this ratio is\nindependent of x and independent of the DGLAP evolution of the gluon PDF. As a\nresult, we show that the charm structure function and the reduced charm\ncross-section exponents do not have the same behaviour at very low x. This\ndifference is independent of the input gluon distribution functions and\npredicts the non-linear effects and some evidence for shadowing and\nantishadowing at HERA and RHIC.", "category": "hep-ph" }, { "text": "Quark-Lepton Flavor Democracy and the Non-Existence of the Fourth\n Generation: In the Standard Model with two Higgs doublets (type II), which has a\nconsistent trend to a flavor gauge theory and its related flavor democracy in\nthe quark and the leptonic sectors (unlike the minimal Standard Model) when the\nenergy of the probes increases, we impose the mixed quark-lepton flavor\ndemocracy at high ``transition'' energy and assume the usual see-saw mechanism,\nand consequently find out that the existence of the fourth generation of\nfermions in this framework is practically ruled out.", "category": "hep-ph" }, { "text": "Neutralino Dark Matter and Other LHC Predictions from Quasi Yukawa\n Unification: We explore the dark matter and LHC implications of t-b-tau quasi Yukawa\nunification in the framework of supersymmetric models based on the gauge\nsymmetry G=SU(4)_{c}\\times SU(2)_{L}\\times SU(2)_{R}. The deviation from exact\nYukawa unification is quantified by a dimensionless parameter C (|C| <~ 0.2),\nsuch that the Yukawa couplings at M_GUT are related by y_t:y_b:y_tau=|1+C| :\n|1-C| : |1+3C|. In contrast to earlier studies which focused on universal\ngaugino masses, we consider non-universal gaugino masses at M_GUT that are\ncompatible with the gauge symmetry G. We perform two independent scans of the\nfundamental parameter space, one of which employs ISAJET, while the other uses\nSoftSusy interfaced with SuperIso. These scans reveal qualitatively similar\nallowed regions in the parameter space, and yield a variety of neutralino dark\nmatter scenarios consistent with the observations. These include stau and\nchargino coannihilation scenarios, the A-resonance scenario, as well as\nHiggsino dark matter solution which is more readily probed by direct detection\nsearches. The gluino mass is found to be <~ 4.2 TeV, the stop mass is >~ 2 TeV,\nwhile the first two family squarks and sleptons are of order 4-5 TeV and 3 TeV\nrespectively.", "category": "hep-ph" }, { "text": "$D_s$ Lifetime, $m_b$, $m_c$ and $|V_{cb}|$ in the Heavy Quark Expansion: We present some straightforward applications of the QCD heavy quark\nexpansion, stated in previous papers [1-3], to the inclusive widths of heavy\nflavour hadrons. We address the question of the $D_s$ lifetime and argue that\n-- barring Weak Annihilation (WA) -- $\\tau (D_s)$ is expected to exceed $\\tau\n(D^0)$ by several percent; on the other hand WA could provide a difference of\nup to $10\\div20\\%$ of {\\it any} sign. We extract $m_c$, $m_b$ and $|V_{cb}|$\nfrom $\\Gamma\\ind{SL}(D^+)$ and $\\Gamma\\ind{SL}(B)$. The values of the quark\nmasses are somewhat higher, but compatible with estimates from QCD sum rules;\nwe obtain $|V_{cb}|\\simeq 0.043$ for $\\tau (B)=1.4$ psec and\n$BR_{SL}(B)=10.5$\\% . We discuss the associated uncertainties in the $1/m_Q$\nexpansion as well as some consequences for other electroweak decays.", "category": "hep-ph" }, { "text": "On Supersymmetries: After reviewing electroweak (EW) scale supersymmetry (susy) and split susy,\nas well as their implications in very high energy cosmic rays, I present a high\nscale susy model for fermion masses. An O(0.1) nu_e-nu_{tau} mixing is\nexpected.", "category": "hep-ph" }, { "text": "On the Spectrum of Lattice Massive SU(2) Yang-Mills: On the basis of extended simulations we provide some results concerning the\nspectrum of Massive SU(2) Yang-Mills on the lattice. We study the \"time\"\ncorrelator of local gauge invariant operators integrated over the remaining\nthree dimensions. The energy gaps are measured in the isospin I=0,1 and\ninternal spin J=0,1 channels. No correlation is found in the I=1,J=0 channel.\nIn the I=1, J=1 channel and far from the critical mass value $m_c$ the energy\ngap roughly follows the bare value $m$ (vector mesons). In approaching the\ncritical value $m_c$ at $\\beta$ fixed, there is a bifurcation of the energy\ngap: one branch follows the value $m$, while the new is much larger and it\nshows a more and more dominant weight. This phenomenon might be the sign of two\nimportant features: the long range correlation near the fixed point at $\\beta\n\\to \\infty$ implied by the low energy gap and the screening (or confining)\nmechanisms across the $m=m_c$ associated to the larger gap. The I=0, J=0,1 gaps\nare of the same order of magnitude, typically larger than the I=1, J=1 gap (for\n$m>>m_c$). For $m\\sim m_c$ both I=0 gaps have a dramatic drop with minima near\nthe value $m$. This behavior might correspond to the formation of I=0 bound\nstates both in the J=0 and J=1 channels.", "category": "hep-ph" }, { "text": "Charmless $B_{u,d,s}\\to VT$ decays in perturbative QCD approach: Motivated by the experimental data, we study charmless $B_{u,d,s}\\to VT$ ($V$\nand $T$ denote light vector and tensor mesons respectively) decays in the\nperturbative QCD approach. The predictions of branching ratios, polarization\nfractions and direct CP violations are given in detail. Specifically, within\nthis approach we have calculated the polarization fractions and the branching\nratios of $B\\to \\phi(K_2^{*-}, \\bar K_2^{*0})$ which agree well with the\nobserved experimental data, however the branching ratios of $B\\to\n\\omega(K_2^{*-}, \\bar K_2^{*0})$ are hard to be explained, where the\npolarization fractions are well accommodated. The tree dominated channels with\na vector meson emitted have longitudinal polarization fraction of 90%, while\nthe penguin dominating ones have subtle polarization fractions. Fortunately,\nmost branching ratios of $B_{u,d}$ decays are of the order $10^{-6}$, which\nwould be straight forward for experimental observations. For the $B_s$ decays\nthe branching ratios can reach the order of $10^{-6}$ in tree dominated decays,\nwhile in penguin dominated decays those are of order of $10^{-7}$ which require\nmore experimental data to be observed.", "category": "hep-ph" }, { "text": "Higgs production in hadron collisions: soft and virtual QCD corrections\n at NNLO: We consider QCD corrections to Higgs boson production through gluon-gluon\nfusion in hadron collisions. Using the recently evaluated two-loop amplitude\nfor this process and the corresponding factorization formulae for soft-gluon\nbremsstrahlung at O(alpha_s^2), we compute the soft and virtual contributions\nto the NNLO cross section. We also discuss soft-gluon resummation at\nnext-to-next-to-leading logarithmic accuracy. Numerical results for Higgs boson\nproduction at the LHC are presented.", "category": "hep-ph" }, { "text": "Primordial magnetic fields, anomalous isocurvature fluctuations and Big\n Bang nucleosynthesis: We show that the presence of primordial stochastic (hypercharge) magnetic\nfields before the electroweak (EW) phase transition induces isocurvature\nfluctuations (baryon number inhomogeneities). Depending on the details of the\nmagnetic field spectrum and on the particle physics parameters (such as the\nstrength of the EW phase transition and electron Yukawa couplings) these\nfluctuations may survive until the Big Bang nucleosynthesis (BBN). Their\nlenghtscale may exceed the neutron diffusion length at that time, while their\nmagnitude can be so large that sizable antimatter domains are present. This\nprovides the possibility of a new type of initial conditions for\nnon-homogeneous BBN or, from a more conservative point of view, stringent\nbounds on primordial magnetic fields.", "category": "hep-ph" }, { "text": "Excess Cross-Sections at the Electroweak Scale in the Sextet Quark\n ``Standard Model'': If dynamical electroweak symmetry breaking is due to a flavor doublet of\ncolor sextet quarks, enhanced electroweak scale QCD instanton interactions may\nproduce a large top mass, raise the $\\eta_6$ axion mass, and also explain the\nexcesses in the DIS cross-section at HERA and jet cross-sections at the\nTevatron.", "category": "hep-ph" }, { "text": "Determination of QCD condensates from tau-decay data: We have used the latest data from the ALEPH Collaboration to extract values\nfor QCD condensates up to dimension d=12 in the V-A channel and up to dimension\nd=8 in the V, A and V+A channels. Performing 2- and 3-parameter fits, we obtain\nnew results for the correlations of condensates. The results are consistent\namong themselves and agree with most of the previous results found in the\nliterature.", "category": "hep-ph" }, { "text": "Initial fields and instability in the classical model of the heavy-ion\n collision: Color Glass Condensate (CGC) provides a classical description of dense gluon\nmatter at high energies. Using the McLerran-Venugopalan (MV) model we calculate\nthe initial energy density \\epsilon(\\tau) in the early stage of the\nrelativistic nucleus-nucleus collision. Our analytical formula reproduces the\nquantitative results from lattice discretized simulations and leads to an\nestimate \\epsilon(\\tau=0.1fm)=40-50GeV/fm^3 in the Au-Au collision at RHIC\nenergy. We then formulate instability with respect to soft fluctuations that\nviolate boost invariance inherent to hard CGC backgrounds. We find unstable\nmodes arising as a result of ensemble average over the initial CGC fields.", "category": "hep-ph" }, { "text": "Chiral asymmetry and axial anomaly in magnetized relativistic matter: The induced axial current and the chiral anomaly are studied in the normal\nphase of magnetized relativistic matter. A special attention is paid to the\nrole of the chiral shift parameter Delta, leading to a relative shift of the\nlongitudinal momenta in the dispersion relations of opposite chirality\nfermions. In the Nambu-Jona-Lasinio model, it is shown directly from the form\nof the gap equation that Delta necessarily exists in the normal phase in a\nmagnetic field. By making use of the gauge invariant point-splitting\nregularization, we then show that the presence of Delta essentially modifies\nthe form of the axial current, but does not affect the conventional axial\nanomaly relation. By recalculating the axial current with the proper-time\nregularization, we conclude that the result is robust with respect to a\nspecific regularization scheme used.", "category": "hep-ph" }, { "text": "Jet quenching phenomenology from soft-collinear effective theory with\n Glauber gluons: We present the first application of a recently-developed effective theory of\njet propagation in matter SCETG to inclusive hadron suppression in\nnucleus-nucleus collisions at the LHC. SCETG-based splitting kernels allow us\nto go beyond the traditional energy loss approximation and unify the treatment\nof vacuum and medium-induced parton showers. In the soft gluon emission limit,\nwe establish a simple analytic relation between the QCD evolution and energy\nloss approaches to jet quenching. We quantify the uncertainties associated with\nthe implementation of the in-medim modification of hadron production cross\nsections and show that the coupling between the jet and the medium can be\nconstrained with better than 10% accuracy.", "category": "hep-ph" }, { "text": "The Effect of Weak Interactions on the Ultra-Relativistic Bose-Einstein\n Condensation Temperature: We calculate the ultra-relativistic Bose-Einstein condensation temperature of\na complex scalar field with weak lambda Phi^4 interaction. We show that at high\ntemperature and finite density we can use dimensional reduction to produce an\neffective three-dimensional theory which then requires non-perturbative\nanalysis. For simplicity and ease of implementation we illustrate this process\nwith the linear delta expansion.", "category": "hep-ph" }, { "text": "Has HERA reached a new QCD regime?: These notes are a summary of our efforts to answer the question in the title.\nOur answer is in the affirmative as: (i) HERA data indicate a large value of\nthe gluon structure function; (ii) no contradictions with the asymptotic\npredictions of high density QCD have been observed; and (iii) the numerical\nestimates of our model give a natural description of the size of deviation from\nthe routine DGLAP explanation. We discuss the alternative approaches and\npossible new experiments.", "category": "hep-ph" }, { "text": "Electroweak and supersymmetric two-loop corrections to lepton anomalous\n magnetic and electric dipole moments: Using the effective Lagrangian method, we analyze the electroweak corrections\nto the anomalous dipole moments of lepton from some special two-loop diagrams\nwhere a closed neutralino/chargino loop is inserted into relevant two Higgs\ndoublet one-loop diagrams in the minimal supersymmetric extension of the\nstandard model with CP violation. Considering the translational invariance of\nloop momenta and the electromagnetic gauge invariance, we get all dimension 6\noperators and derive their coefficients. After applying equations of motion to\nthe external leptons, we obtain the anomalous dipole moments of lepton. The\nnumerical results imply that there is parameter space where the contributions\nto the muon anomalous dipole moments from this sector may be significant.", "category": "hep-ph" }, { "text": "Nonequilibrium Chiral Dynamics and Effective Lagrangians: We review our recent work on Chiral Lagrangians out of thermal equilibrium,\nwhich are introduced to analyse the pion gas formed after a Relativistic Heavy\nIon Collision. Chiral Perturbation Theory is extended by letting $\\fpi$ be time\ndependent and allows to describe explosive production of pions in parametric\nresonance. This mechanism could be relevant if hadronization occurs at the\nchiral phase transition.", "category": "hep-ph" }, { "text": "Comment on the Theta+ width and mass: We discuss the relatively low mass and narrow width prediction for the exotic\nbaryon Theta+, and comment on recent statements by R.L. Jaffe on the subject.\nWe reaffirm that a narrow width of 3.6-11.2 MeV follows from the equations of\nour 1997 paper.", "category": "hep-ph" }, { "text": "Positivity issues for the pinch-technique gluon propagator and their\n resolution: Although gauge-boson propagators in asymptotically-free gauge theories\nsatisfy a dispersion relation, they do not satisfy the K\\\"allen-Lehmann (KL)\nrepresentation because the spectral function changes sign. We argue that this\nis a simple consequence of asymptotic freedom. On the basis of the QED-like\nWard identities of the pinch technique (PT) we claim that the product of the\ncoupling $g^2$ and the scalar part $\\hat{d}(q^2)$ of the PT propagator, which\nis both gauge invariant and renormalization-group invariant, can be factored\ninto the product of the running charge $\\bar{g}^2(q^2)$ and a term\n$\\hat{H}(q^2)$ both of which satisfy the KL representation although their\nproduct does not. We show that this behavior is consistent with some simple\nanalytic models that mimic the gauge-invariant PT Schwinger-Dyson equations\n(SDE) provided that the dynamic gauge boson mass is sufficiently large. The PT\nSDEs do not depend directly on the PT propagator through $\\hat{D}$ but only\nthrough $\\hat{H}$.", "category": "hep-ph" }, { "text": "Discrete Symmetry, Neutrino Magnetic Moment and the 17 Kev Neutrino: The problem of generating large transition magnetic moments for nearly\nmassless neutrinos in a truly three--generation case is discussed. A model to\nachieve the same by exploiting an octahedral symmetry is presented. The scheme\nalso accomodates a radiatively generated mass of $17\\:keV$ for a pseudo--Dirac\nneutrino that decays rapidly through the Majoron channel.", "category": "hep-ph" }, { "text": "Hadronic structure on the light-front VI. Generalized parton\n distributions of unpolarized hadrons: We discuss the generalized parton distributions (GPDs) for unpolarized\nhadrons, as a continuation of our recent work on hadronic structure on the\nlight front. We analyze the unpolarized GPDs for the light nucleon and delta,\nas well as generic mesons, using the lowest Fock states. We use these GPDs to\nreconstruct the charge and gravitational form factors, and discuss their\nrelative sizes. The results are also compared to reported QCD lattice results.", "category": "hep-ph" }, { "text": "Composite Higgs to two Photons and Gluons: We introduce a simple framework to estimate the composite Higgs boson\ncoupling to two-photon in Technicolor extensions of the standard model. The\nsame framework allows us to predict the composite Higgs to two-gluon process.\nWe compare the decay rates with the standard model ones and show that the\ncorrections are typically of order one. We suggest, therefore, that the\ntwo-photon decay process can be efficiently used to disentangle a light\ncomposite Higgs from the standard model one. We also show that the Tevatron\nresults for the gluon-gluon fusion production of the Higgs either exclude the\ntechniquarks to carry color charges to the 95% confidence level, if the\ncomposite Higgs is light, or that the latter must be heavier than around 200\nGeV.", "category": "hep-ph" }, { "text": "The Gerasimov-Drell-Hearn sum rule and the infinite-momentum limit: We study the current-algebra approach to the Gerasimov-Drell-Hearn sum rule,\npaying particular attention to the infinite-momentum limit. Employing the\norder-alpha^2 Weinberg-Salam model of weak interactions as a testing ground, we\nfind that the legitimacy of the infinite-momentum limit is intimately connected\nwith the validity of the naive equal-times algebra of electric charge\ndensities. Our results considerably reduce the reliability of a recently\nproposed modification of the Gerasimov-Drell-Hearn sum rule, originating from\nan anomalous charge-density algebra.", "category": "hep-ph" }, { "text": "Current correlators to all orders in the quark masses: The contributions to the coefficient functions of the quark and the mixed\nquark-gluon condensate to mesonic correlators are calculated for the first time\nto all orders in the quark masses, and to lowest order in the strong coupling\nconstant. Existing results on the coefficient functions of the unit operator\nand the gluon condensate are reviewed. The proper factorization of short- and\nlong-distance contributions in the operator product expansion is discussed in\ndetail. It is found that to accomplish this task rigorously the operator\nproduct expansion has to be performed in terms of non-normal-ordered\ncondensates. The resulting coefficient functions are improved with the help of\nthe renormalization group. The scale invariant combination of dimension 5\noperators, including mixing with the mass operator, which is needed for the\nrenormalization group improvement, is calculated in the leading order.", "category": "hep-ph" }, { "text": "Cabibbo-favored $\u039b^+_c\\to\u039ba_{0}(980)^+$ decay in the final\n state interaction: The anti-triplet charmed baryon decays with the light scalar mesons are\nrarely measured, whereas the recent observation of the Cabibbo-favored\n$\\Lambda_c^+\\to \\Lambda\\eta\\pi^+$ decay hints a possible $\\Lambda_c^+\\to\\Lambda\na_0(980)^+,a_0(980)^+\\to \\eta\\pi^+$ process. We hence study the\n$\\Lambda_c^+\\to\\Lambda a_0(980)^+$ decay. Particularly, it is found that the\nfinal state interaction can give a significant contribution, where\n$\\Sigma^{+}(1385)$ and $\\eta$ in $\\Lambda_c^+\\to \\Sigma^{+}(1385)\\eta$ by\nexchanging a charged pion are transformed as $\\Lambda$ and $a_0(980)^+$,\nrespectively. Accordingly, we predict ${\\cal B}(\\Lambda_c^+\\to\\Lambda\na_0(980)^+)=(1.7^{+2.8}_{-1.0}\\pm 0.3)\\times 10^{-3}$, accessible to the\nBESIII, BELLEII and LHCb experiments.", "category": "hep-ph" }, { "text": "The static potential in QCD to two loops: We evaluate the static QCD potential to two--loop order. Compared to a\nprevious calculation a sizable reduction of the two--loop coefficient $a_2$ is\nfound.", "category": "hep-ph" }, { "text": "Update of the Hagedorn mass spectrum: We present an update of the Hagedorn hypothesis of the exponential growth of\nthe number of hadronic resonances with mass. We use the newest available\nexperimental data for the non-strange mesons and baryons, as well as fill in\nsome missing states according to the observation that the high-lying states\nform chiral multiplets. The results show, especially for the case of the\nmesons, that the Hagedorn growth continues with the increasing mass, with the\nnew states lining up along the exponential growth.", "category": "hep-ph" }, { "text": "Limits on Cosmological Variation of Strong Interaction and Quark Masses\n from Big Bang Nucleosynthesis, Cosmic, Laboratory and Oklo Data: Recent data on cosmological variation of the electromagnetic fine structure\nconstant from distant quasar (QSO) absorption spectra have inspired a more\ngeneral discussion of possible variation of other constants. We discuss\nvariation of strong scale and quark masses. We derive the limits on their\nrelative change from (i) primordial Big-Bang Nucleosynthesis (BBN); (ii)\n Oklo natural nuclear reactor, (iii) quasar absorption spectra, and (iv)\nlaboratory measurements of hyperfine intervals.", "category": "hep-ph" }, { "text": "Higgs Physics: These lectures review the background to Higgs physics, its current status\nfollowing the discovery of a/the Higgs boson at the LHC, models of Higgs\nphysics beyond the Standard Model and prospects for Higgs studies in future\nruns of the LHC and at possible future colliders.", "category": "hep-ph" }, { "text": "Geometry of the neutrino mixing space: We study a geometric structure of a physical region of neutrino mixing\nmatrices as part of the unit ball of the spectral norm. Each matrix from the\ngeometric region is a convex combination of unitary PMNS matrices. The disjoint\nsubsets corresponding to a different minimal number of additional neutrinos are\ndescribed as relative interiors of faces of the unit ball. We determined the\nCarath\\'eodory's number showing that, at most, four unitary matrices of\ndimension three are necessary to represent any matrix from the neutrino\ngeometric region. For matrices which correspond to scenarios with one and two\nadditional neutrino states, the Carath\\'eodory's number is two and three,\nrespectively. Further, we discuss the volume associated with different\nmathematical structures, particularly with unitary and orthogonal groups, and\nthe unit ball of the spectral norm. We compare the obtained volumes to the\nvolume of the region of physically admissible mixing matrices for both the\nCP-conserving and CP-violating cases in the present scenario with three\nneutrino families and scenarios with the neutrino mixing matrix of dimension\nhigher than three.", "category": "hep-ph" }, { "text": "Probing New Physics With b Decays: I discuss how b decays can be used to unravel new physics beyond the Standard\nModel. Decays second order in the weak interaction involving loops and CP\nviolation are emphasized. This information is complementary to that obtainable\nwith higher energy machines.", "category": "hep-ph" }, { "text": "A screening mechanism for extra W and Z gauge bosons: We generalize a previous construction of a fermiophobic model to the case of\nmore than one extra $W$ and $Z$ gauge bosons. We focus in particular on the\nexistence of screening configurations and their implication on the gauge boson\nmass spectrum. One of these configurations allows for the existence of a set of\nrelatively light new gauge bosons, without violation of the quite restrictive\nbounds coming from the $\\rho_{\\rm NC}$ parameter. The links with Bess and\ndegenerate Bess models are also discussed. Also the signal given here by this\nmore traditional gauge extension of the SM could help to disentangle it from\nthe towers of Kaluza-Klein states over $W$ and $Z$ gauge bosons in extra\ndimensions.", "category": "hep-ph" }, { "text": "A study of the resonances $K_{0}^{*}(800)$ and $K_{0}^{*}(1430)$: We study the scalar kaonic states $K_{0}^{\\ast}(800)$ and\n$K_{0}^{\\ast}(1430)$ by using a relativistic QFT Lagrangian in which only a\nsingle kaonic field corresponding to the well-established scalar state\n$K_{0}^{\\ast}(1430)$ is considered and in which both derivative and\nnon-derivative interaction terms are taken into account. Even if the scalar\nspectral function shows a unique peak close to $1.4$ GeV, we find two poles in\nthe complex plane: $1.413\\pm0.002-i(0.127\\pm0.003)$ GeV, which is related to\nthe seed quark-antiquark state $K_{0}^{\\ast}(1430),$ and\n$0.746\\pm0.019-i(262\\pm0.014)$ GeV, which is an additional companion pole\nrelated to $K_{0}^{\\ast}(800)$. As a further investigation for increasing\n$N_{c}$ confirms, $K_{0}^{\\ast}(800)$ emerges as a dynamically generated\nfour-quark object as a consequence of pion-kaon loops.", "category": "hep-ph" }, { "text": "A note on Higgs decays into $Z$ boson and $J/\u03a8(\u03a5)$: Rare decays $h\\to Z V$ with $V$ denoting the narrow $c\\bar{c}$ or $b\\bar{b}$\nresonances, such as $J/\\Psi$ or $\\Upsilon$ states, have been analyzed. Within\nthe standard model, these channels may proceed through the tree-level\ntransition $h\\to ZZ^*$ with the virtual $Z^*\\to V$, and also loop-induced\nprocess $h\\to Z\\gamma^*$, followed by $\\gamma^*\\to V$. Our analysis shows that,\nfor the bottomonium final states, the decay rate of $h\\to Z \\Upsilon$ from the\nloop-induced process is small and the former transition gives the dominant\ncontribution; while, for the charmonium final states, $\\Gamma(h\\to Z J/\\Psi)$\nand $\\Gamma(h\\to Z\\Psi(2S))$ induced by $h\\to Z\\gamma^* \\to Z V$ could be\ncomparable to the contribution given by the tree-level $h\\to ZZ^*\\to Z V$\ntransition.", "category": "hep-ph" }, { "text": "Axionic Mirage Mediation: In this talk, we propose a model of mirage mediation, in which Peccei-Quinn\nsymmetry is incorporated. In this \\textit{axionic mirage mediation}, it is\nshown that the Peccei-Quinn symmetry breaking scale is dynamically determined\naround $10^{10}$ GeV to $10^{12}$ GeV due to the supersymmetry breaking\neffects. The problems in the original mirage mediation such as the\n$\\mu$-problem and the moduli problem can be solved simultaneouly. Furthermore,\nin our model the axino, which is the superpartner of the axion, is the lightest\nsparticle.", "category": "hep-ph" }, { "text": "Deuteron Magnetic Quadrupole Moment From Chiral Effective Field Theory: We calculate the magnetic quadrupole moment (MQM) of the deuteron at leading\norder in the systematic expansion provided by chiral effective field theory. We\ntake into account parity and time-reversal violation which, at the quark-gluon\nlevel, results from the QCD vacuum angle and dimension-six operators that\noriginate from physics beyond the Standard Model. We show that the deuteron MQM\ncan be expressed in terms of five low-energy constants that appear in the\nparity- and time-reversal-violating nuclear potential and electromagnetic\ncurrent, four of which also contribute to the electric dipole moments of light\nnuclei. We conclude that the deuteron MQM has an enhanced sensitivity to the\nQCD vacuum angle and that its measurement would be complementary to the\nproposed measurements of light-nuclear EDMs.", "category": "hep-ph" }, { "text": "Predicting the Pion and Eta Masses as Quantum Corrections without Quark\n Masses: This paper is removed because it used an approximation, which alters some of\nthe conclusions. Another paper will be written in the near future.", "category": "hep-ph" }, { "text": "Probing the Dark Matter of Three-loop Radiative Neutrino Mass Generation\n Model with the Cherenkov Telescope Array: We investigate the prospect of detecting the Dark Matter (DM) candidate in\nthe three-loop radiative neutrino mass generation model extended with large\nelectroweak multiplets of the Standard Model (SM) gauge group, at the future\nimaging atmospheric Cherenkov telescope known as the Cherenkov Telescope Array\n(CTA). We find that the addition of such large electroweak multiplets leads to\na sizable Sommerfeld enhanced annihilation of the DM with $O(\\text{TeV})$ mass,\ninto the SM gauge bosons which results in continuum and line-like spectra of\nvery high energy (VHE) gamma-rays, and therefore becomes observable for the\nCTA. We determine the viable models by setting the upper limit on the\n$SU(2)_{L}$ isospin of the multiplets from the partial-wave unitarity\nconstraints and the appearance of low-scale Landau pole in the gauge coupling.\nAfterwards, by considering the continuum VHE gamma-rays produced from the DM\nannihilation at the Galactic center, we probe the parameter space of the model\nusing the sensitivity reach of the CTA.", "category": "hep-ph" }, { "text": "Probing initial geometrical anisotropy and final azimuthal anisotropy in\n heavy-ion collisions at Large Hadron Collider energies through event-shape\n engineering: Anisotropic flow is accredited to have effects from the initial state\ngeometry and fluctuations in the nuclear overlap region. The elliptic flow\n($v_2$) and triangular flow ($v_3$) coefficients of the final state particles\nare expected to have influenced by eccentricity ($\\varepsilon_2$) and\ntriangularity ($\\varepsilon_3$) of the participants, respectively. In this\nwork, we study $v_2$, $v_3$, $\\varepsilon_2$, $\\varepsilon_3$ and the\ncorrelations among them with respect to event topology in the framework of a\nmulti-phase transport model (AMPT). We use transverse spherocity and reduced\nflow vector as event shape classifiers in this study. Transverse spherocity has\nthe unique ability to separate events based on geometrical shapes, i.e., jetty\nand isotropic, which pertain to pQCD and non-pQCD domains of particle\nproduction in high-energy physics, respectively. We use the two-particle\ncorrelation method to study different anisotropic flow coefficients. We\nconfront transverse spherocity with a more widely used event shape classifier\n-- reduced flow vector ($q_n$) and they are found to have significant\n(anti-)correlations among them. We observe significant spherocity dependence on\n$v_2$, $v_3$ and $\\varepsilon_2$. This work also addresses transverse momentum\ndependent crossing points between $v_2$ and $v_3$, which varies for different\ncentrality and spherocity percentiles.", "category": "hep-ph" }, { "text": "Hadron-hadron collision mode in ReneSANCe-v1.3.0: We report an implementation of the hadron-hadron ($pp$ and $p\\bar{p}$)\ncollision mode to the Monte Carlo event generator ReneSANCe - the code that was\npreviously developed for $e^+e^-$ collisions. The described extension of\nReneSANCe currently contains neutral and charged current Drell-Yan prosesses\n$pp[p\\bar{p}] \\to ZX \\to \\ell^+\\ell^- X$, $pp[p\\bar{p}] \\to W^+X \\to\n\\ell^+\\nu_\\ell X$ and $pp[p\\bar{p}] \\to W^-X \\to \\ell^-\\bar{\\nu}_\\ell X$. We\ntake into account complete one-loop electroweak (EW) and one-loop QCD\ncorrections to these processes. The calculation is based on the SANC (Support\nfor Analytic and Numeric Calculations for experiments at colliders) modules.\nThe generator is constructed in such a way that new processes can be easily\nadded. The paper contains a theoretical description of the SANC approach,\nnumerical validations and a manual.", "category": "hep-ph" }, { "text": "Dissipative Effects on Reheating after Inflation: The inflaton must convert its energy into radiation after inflation, which,\nin a conventional scenario, is caused by the perturbative inflaton decay. This\nreheating process would be much more complicated in some cases: the decay\nproducts obtain masses from an oscillating inflaton and thermal environment,\nand hence the conventional reheating scenario can be modified. We study in\ndetail processes of particle production from the inflaton, their subsequent\nthermalization and evolution of inflaton/plasma system by taking dissipation of\nthe inflaton in a hot plasma into account. It is shown that the reheating\ntemperature is significantly affected by these effects.", "category": "hep-ph" }, { "text": "The connection between the DRED and NSVZ renormalisation schemes: We explore the relationship between the DRED and NSVZ schemes. Using certain\nexact results for the soft scalar mass $\\beta$-function, we derive the\ntransformation of $\\alpha^{\\DRED}$ to $\\alpha^{\\NSVZ}$ through terms of order\n$\\alpha^4$. We thus incidentally determine $\\beta_{\\alpha}^{\\DRED}$ through\nfour loops, and we compare our result to a previous Pad\\'e Approximant\nprediction.", "category": "hep-ph" }, { "text": "Herwig++ 2.2 Release Note: A new release of the Monte Carlo program Herwig++ (version 2.2) is now\navailable. This version includes a number of improvements including: matrix\nelements for the production of an electroweak gauge boson, W and Z, in\nassociation with a jet; several new processes for Higgs production in\nassociation with an electroweak gauge boson; and the matrix element correction\nfor QCD radiation in Higgs production via gluon fusion.", "category": "hep-ph" }, { "text": "Late decaying 2-component dark matter scenario as an explanation of the\n AMS-02 positron excess: The long standing anomaly in the positron flux as measured by the PAMELA and\nAMS-02 experiments could potentially be explained by dark matter (DM)\nannihilations. This scenario typically requires a large \"boost factor\" to be\nconsistent with a thermal relic dark matter candidate produced via freeze-out.\nHowever, such an explanation is disfavored by constraints from CMB observations\non energy deposition during the epoch of recombination. We discuss a scenario\ncalled late-decaying two-component dark matter (LD2DM), where the entire DM\nconsists of two semi-degenerate species. Within this framework, the heavier\nspecies is produced as a thermal relic in the early universe and decays to the\nlighter species over cosmological timescales. Consequently, the lighter species\nbecomes the DM which populates the universe today. We show that annihilation of\nthe lighter DM species with an enhanced cross-section, produced via such a\nnon-thermal mechanism, can explain the observed AMS-02 positron flux while\navoiding CMB constraints. The observed DM relic density can be correctly\nreproduced as well with simple s-wave annihilation cross-sections. We\ndemonstrate that the scenario is safe from CMB constraints on late-time energy\ndepositions during the cosmic \"dark ages\". Interestingly, structure formation\nconstraints force us to consider small mass splittings between the two dark\nmatter species. We explore possible cosmological and particle physics\nsignatures in a toy model that realizes this scenario.", "category": "hep-ph" }, { "text": "Testing collinear factorization and nuclear parton distributions with pA\n collisions at the LHC: Global perturbative QCD analyses, based on large data sets from\nelectron-proton and hadron collider experiments, provide tight constraints on\nthe parton distribution function (PDF) in the proton. The extension of these\nanalyses to nuclear parton distributions (nPDF) has attracted much interest in\nrecent years. nPDFs are needed as benchmarks for the characterization of hot\nQCD matter in nucleus-nucleus collisions, and attract further interest since\nthey may show novel signatures of non- linear density-dependent QCD evolution.\nHowever, it is not known from first principles whether the factorization of\nlong-range phenomena into process-independent parton distribution, which\nunderlies global PDF extractions for the proton, extends to nuclear effects. As\na consequence, assessing the reliability of nPDFs for benchmark calculations\ngoes beyond testing the numerical accuracy of their extraction and requires\nphenomenological tests of the factorization assumption. Here we argue that a\nproton-nucleus collision program at the LHC would provide a set of measurements\nallowing for unprecedented tests of the factorization assumption underlying\nglobal nPDF fits.", "category": "hep-ph" }, { "text": "Collisions and collective flavor conversion: Integrating out the fast\n dynamics: In dense astrophysical environments, notably core-collapse supernovae and\nneutron star mergers, neutrino-neutrino forward scattering can spawn flavor\nconversion on very short scales. Scattering with the background medium can\nimpact collective flavor conversion in various ways, either damping\noscillations or possibly setting off novel collisional flavor instabilities\n(CFIs). A key feature in this process is the slowness of collisions compared to\nthe much faster dynamics of neutrino-neutrino refraction. Assuming spatial\nhomogeneity, we leverage this hierarchy of scales to simplify the description\naccounting only for the slow dynamics driven by collisions. We illustrate our\nnew approach both in the case of CFIs and in the case of fast instabilities\ndamped by collisions. In both cases, our strategy provides new equations, the\nslow-dynamics equations, that simplify the description of flavor conversion and\nallow us to qualitatively understand the final state of the system after the\ninstability, either collisional or fast, has saturated.", "category": "hep-ph" }, { "text": "Effective Theory for Heavy Quarkonia Decays: An effective theory approach to heavy quarkonia decays based on the $1/m_Q$\nexpansion is introduced. Its application to decays in which the two heavy\nquarks annihilate is discussed.", "category": "hep-ph" }, { "text": "Inverse Primakoff Scattering for Axionlike Particle Coupling: Axionlike particles (ALPs) can be produced in the Sun, and are considered\nviable candidates for the cosmological dark matter (DM). It can decay into two\nphotons or interact with matter. We identify new inelastic channels of inverse\nPrimakoff processes due to atomic excitation and ionization. Their cross\nsections are derived by incorporating full electromagnetic fields of atomic\ncharge and current densities, and computed by well-benchmarked atomic many-body\nmethods. Complementing data from the underground XENONnT and surface TEXONO\nexperiments are analyzed. Event rates and sensitivity reaches are evaluated\nwith respect to solar- and DM-ALPs. New parameter space in ALP couplings with\nthe photons versus ALP masses in (1~eV$-$10~keV) not previously accessible to\nlaboratory experiments are probed and excluded with solar-ALPs. However, at\nregions where DM-ALPs have already decayed, there would be no ALP-flux and\nhence no interactions at the detectors in direct search experiments. No physics\nconstraints can be derived. Future projects would be able to evade the\nstability bound and open new observable windows in (100~eV$-$1~MeV) for\nDM-ALPs.", "category": "hep-ph" }, { "text": "Multi-color QCD at High Energies and Exactly Solvable Lattice Theories: We examine the generalized leading-logarithmic approximation (LLA) equations\nfor compound states of n-reggeized gluons. It is shown that in multi-color QCD,\nwhen $N_c \\rightarrow \\infty$, these equations have a sufficient number of\nconservation laws to be exactly solvable. Holomorphic factorization of the wave\nfunctions is used to reduce the corresponding quantum mechanical problem to the\nsolution of the one-dimensional Heisenberg model with the spins being the\ngenerators of the M$\\ddot{o}$bius group of conformal transformations.", "category": "hep-ph" }, { "text": "Resonances in a sudden chemical freeze-out model: The prediction for $p_T$ spectra of various resonances produced in Pb+Pb\ncollisions at 2.76 TeV at the LHC in equilibrium and non-equilibrium models is\nmade. It includes the $\\eta$, $\\rho$(770), $\\Sigma$(1385), $\\Lambda$(1520), and\n$\\Xi$(1530). The apparent differences may allow to distinguish between the\nmodels.", "category": "hep-ph" }, { "text": "Rare Z-decay into light pseudoscalar bosons in the simplest little Higgs\n model: The simplest little Higgs model predicts a light pseudoscalar boson $\\eta$\nand opens up some new decay modes for $Z$-boson, such as $Z \\to \\bar{f} f\n\\eta$, $Z\\to \\eta\\eta\\eta$, $Z\\to \\eta\\gamma$ and $Z\\to \\eta gg$. We examine\nthese decay modes in the parameter space allowed by current experiments, and\nfind that the branching ratios can reach $10^{-7}$ for $Z\\to \\bar{b}b\\eta$,\n$10^{-8}$ for $Z\\to \\bar{\\tau}\\tau\\eta$, and $10^{-8}$ for $Z\\to \\eta\\gamma$,\nwhich should be accessible at the GigaZ option of the ILC. However, the\nbranching ratios can reach $10^{-12}$ for $Z\\to \\eta\\eta\\eta$, and $10^{-11}$\nfor $Z\\to \\eta gg$, which are hardly accessible at the GigaZ option.", "category": "hep-ph" }, { "text": "NNLO QCD$\\oplus$QED corrections to Higgs production in bottom quark\n annihilation: We present next-to-next-to leading order (NNLO) quantum electrodynamics (QED)\ncorrections to the production of the Higgs boson in bottom quark annihilation\nat the Large Hadron Collider (LHC) in the five flavor scheme. We have\nsystematically included the NNLO corrections resulting from the interference of\nquantum chromodynamics (QCD) and QED interactions. We have investigated the\ninfrared (IR) structure of the bottom quark form factor up to two loop level in\nQED and in QCD$\\times$QED using K+G equation. We find that the IR poles in the\nform factor are controlled by the universal cusp, collinear and soft anomalous\ndimensions. In addition, we derive the QED as well as QCD$\\times$QED\ncontributions to soft distribution function as well as to the ultraviolet\nrenormalization constant of the bottom Yukawa coupling up to second order in\nstrong coupling and fine structure constant. Finally, we report our findings on\nthe numerical impact of the NNLO results from QED and QCD$\\times$QED at the LHC\nenergies taking into account the dominant NNLO QCD corrections.", "category": "hep-ph" }, { "text": "Photoproduction of $a_{2}(1320)$ in a Regge model: In this work, the photoproduction of $a_{2}(1320)$ off a proton target is\ninvestigated within an effective Lagrangian approach and the Regge model. The\ntheoretical result indicates that the shapes of {the} total and differential\ncross sections of the $\\gamma p\\rightarrow a_{2}^{+}n$ reaction within the\nFeynman (isobar) model are much different from that of the Reggeized treatment.\nThe obtained cross section is compared with the existing experimental results\nat low energies. The $a_{2}(1320)$ production cross section at high energies\ncan be tested by the COMPASS experiment, which can provide important\ninformation for clarifying the role of the Reggeized treatment at that energy\nrange.", "category": "hep-ph" }, { "text": "Quark distributions in polarized rho meson and its comparison with those\n in pion: Valence quark distributions in transversally and longitudinally polarizied\nrho mesons in the region of intermediate x are obtained by generalizied QCD sum\nrules. Power corrections up to d=6 are taken into account. Comparison of the\nresults for pi and rho mesons shows, that polarization effects are very\nsignificant and SU(6) symmetry of distribution functions is absent. The strong\nsuppression of quark and gluon sea distributions in longitudinally polarizied\nrho mesons is found.", "category": "hep-ph" }, { "text": "The T7 flavor symmetry in 3-3-1 model with neutral leptons: We construct a 3-3-1 model based on non-Abelian discrete symmetry $T_7$\nresponsible for the fermion masses. Neutrinos get masses from only anti-sextets\nwhich are in triplets $\\underline{3}$ and $\\underline{3}^*$ under $T_7$. The\nflavor mixing patterns and mass splitting are obtained without perturbation.\nThe tribimaximal form obtained with the breaking $T_7 \\rightarrow Z_3$ in\ncharged lepton sector and both $T_7 \\rightarrow Z_3$ and $Z_3 \\rightarrow\n\\{\\mathrm{Identity}\\}$ must be taken place in neutrino sector but only apart in\nbreakings $Z_3 \\rightarrow \\{\\mathrm{Identity}\\}$ (without contribution of\n$\\si'$), and the upper bound on neutrino mass $\\sum_{i=1}^3m_i$ at the level is\npresented. The Dirac CP violation phase $\\delta$ is predicted to either\n $\\frac{\\pi}{2}$ or $\\frac{3\\pi}{2}$ which is maximal CP violation. From the\nDirac CP violation phase we obtain the relation between Euler's angles which is\nconsistent with the experimental in PDG 2012. On the other hand, the realistic\nlepton mixing can be obtained if both the direction for breakings $T_7\n\\rightarrow Z_3$ and $Z_3 \\rightarrow \\{\\mathrm{Identity}\\}$ are taken place in\nneutrino sectors. The CKM matrix is the identity matrix at the tree-level.", "category": "hep-ph" }, { "text": "On holographic relation between radial meson trajectories and\n deconfinement temperature: The interrelation between the deconfinement temperature of hadron medium and\nparameters of radial Regge trajectories within the bottom-up holographic models\nfor QCD is scrutinized. We show that the lattice data on the deconfinement\ntemperature can yield a powerful restriction on the spectrum of excited mesons\nand glueballs within the framework of holographic approach. The best\nphenomenological agreement and theoretical self-consistency are achieved if the\nscalar meson $f_0(1500)$ is considered as the lightest glueball.", "category": "hep-ph" }, { "text": "Improving NLO-parton shower matched simulations with higher order matrix\n elements: In recent times the algorithms for the simulation of hadronic collisions have\nbeen subject to two substantial improvements: the inclusion, within parton\nshowering, of exact higher order tree level matrix elements (MEPS) and,\nseparately, next-to-leading order corrections (NLOPS). In this work we examine\nthe key criteria to be met in merging the two approaches in such a way that the\naccuracy of both is preserved, in the framework of the POWHEG approach to\nNLOPS. We then ask to what extent these requirements may be fulfilled using\nexisting simulations, without modifications. The result of this study is a\npragmatic proposal for merging MEPS and NLOPS events to yield much improved\nMENLOPS event samples. We apply this method to W boson and top quark pair\nproduction. In both cases results for distributions within the remit of the NLO\ncalculations exhibit no discernible changes with respect to the pure NLOPS\nprediction; conversely, those sensitive to the distribution of multiple hard\njets assume, exactly, the form of the corresponding MEPS results.", "category": "hep-ph" }, { "text": "Supersymmetric Large Extra Dimensions Are Small and/or Numerous: Recently, a scenario has been proposed in which the gravitational scale could\nbe as low as the TeV scale, and extra dimensions could be large and detectable\nat the electroweak scale. Although supersymmetry is not a requirement of this\nscenario, it is nevertheless true that its best-motivated realizations arise in\nsupersymmetric theories (like M theory). We argue here that supersymmetry can\nhave robust, and in some instances fatal, implications for the expected\nexperimental signature for TeV-scale gravity. The signature of the\nsupersymmetric version of the scenario differs most dramatically from what has\nbeen considered in the literature because mass splittings within the gravity\nsupermultiplet in these models are extremely small, implying in particular the\nexistence of a very light spin-one superpartner for the graviton. We compute\nthe implications of this graviphoton, and show that it can acquire\ndimension-four couplings to ordinary matter which can strongly conflict with\nsupernova bounds.", "category": "hep-ph" }, { "text": "The study of the negative pion production in neutron-proton collisions\n at beam momenta below 1.8 GeV/c: A detailed investigation of the reaction np -> pp\\pi^{-} has been carried out\nusing the data obtained with the continuous neutron beam produced by charge\nexchange scattering of protons off a deuterium target. A partial wave\nevent-by-event based maximum likelihood analysis was applied to determine\ncontributions of different partial waves to the pion production process. The\ncombined analysis of the np -> pp\\pi^{-} and pp -> pp\\pi^{0} data measured in\nthe same energy region allows us to determine the contribution of isoscalar\npartial waves (I=0) in the momentum range from 1.1 up to 1.8 GeV/c. The decay\nof isoscalar partial waves into (^1S_0)_{pp}\\pi$ channel provides a good tool\nfor a determination of the pp S-wave scalar scattering length in the final\nstate which was found to be a_{pp}=-7.5\\pm 0.3 fm.", "category": "hep-ph" }, { "text": "Neutrino interactions with a weak slowly varying electromagnetic field: We derive the effective action for processes involving two neutrinos and two\nphotons at energies much below the electron mass. We discuss several\napplications in which one or both photons are replaced by external fields. In\nparticular, Cherenkov radiation and neutrino pair production in weak external\nfields are investigated for massive Dirac neutrinos.", "category": "hep-ph" }, { "text": "Comment on astrophysical consequences of a neutrinophilic 2HDM: Several authors have pointed out that the scalar-mediated interaction of\nneutrinos in a neutriophilic two-Higgs-doublet model (nu2HDM) can be as strong\nas electromagnetic interaction [1-3]. We show that the coupling constants of\nneutrino-scalar interaction are actually restricted to be y_i < 1.5 x 10^{-3}\nby supernova neutrino observation, and further constrained to be y_i < 2.3 x\n10^{-4} by precision measurements of acoustic peaks of the cosmic microwave\nbackground. Based on the energy-loss argument for supernova cores, we derive a\nslightly more restrictive bound y_i < 3.5 x 10^{-5}. Therefore, the nu2HDM has\nlost its spirit of explaining tiny Dirac neutrino masses while keeping neutrino\nYukawa couplings of order one.", "category": "hep-ph" }, { "text": "The Supersymmetric Standard Model, with a Brout-Englert-Higgs boson as\n spin-0 partner of the Z: Supersymmetric extensions of the standard model lead us to expect\nsuperpartners for all particles, spin-0 squarks and sleptons and spin-1/2\ngluinos, charginos and neutralinos, with an odd R-parity making the lightest\none stable. The electroweak breaking is induced by a pair of spin-0 doublets,\nleading to several charged and neutral BE-Higgs bosons. These theories also\nlead to gauge/Higgs unification by providing spin-0 bosons as extra states for\nspin-1 gauge bosons within massive gauge multiplets. In particular, the 125 GeV\nboson recently observed at CERN, most likely a BE-Higgs boson associated with\nthe electroweak breaking, may also be interpreted, up to a mixing angle induced\nby supersymmetry breaking, as the spin-0 partner of the Z under two\nsupersymmetry transformations. We also discuss how the compactification of\nextra dimensions, relying on R-parity and other discrete symmetries, may\ndetermine both the grand-unification and supersymmetry-breaking scales.", "category": "hep-ph" }, { "text": "Constraining Sterile Neutrino Interpretations of the LSND and MiniBooNE\n Anomalies with Coherent Neutrino Scattering Experiments: Results from the LSND and MiniBooNE experiments have been interpreted as\nevidence for a sterile neutrino with a mass near the electronvolt scale. Here\nwe propose to test such a scenario by measuring the coherent elastic scattering\nrate of neutrinos from a pulsed spallation source. Coherent scattering is\nuniversal across all active neutrino flavors, and thus can provide a\nmeasurement of the total Standard Model neutrino flux. By performing\nmeasurements over different baselines and making use of timing information, it\nis possible to significantly reduce the systematic uncertainties and to\nindependently measure the fluxes of neutrinos that originate as $\\nu_{\\mu}$ or\nas either $\\nu_e$ or $\\bar{\\nu}_{\\mu}$. We find that a 100 kg CsI detector\nwould be sensitive to the large fraction of the sterile neutrino parameter\nspace that could potentially account for the LSND and MiniBooNE anomalies.", "category": "hep-ph" }, { "text": "General Issues Connecting Flavor Symmetry and Supersymmetry: We motivate and construct supersymmetric theories with continuous flavor\nsymmetry, under which the electroweak Higgs doublets transform non-trivially.\nFlavor symmetry is spontaneously broken at a large mass scale in a sector of\ngauge-singlet fields; the light Higgs multiplets naturally emerge as special\nlinear combinations that avoid acquiring the generic large mass. Couplings of\nthe light Higgs doublets to light moduli fields from the singlet sector could\nlead to important effects in the phenomenology of the Higgs sector.", "category": "hep-ph" }, { "text": "Gauge dependence of the on-shell renormalized mixing matrices: It was recently pointed out that the on-shell renormalization of the\nCabibbo-Kobayashi-Maskawa (CKM) matrix in the method by Denner and Sack causes\na gauge parameter dependence of the amplitudes. We analyze the gauge dependence\nof the on-shell renormalization of the mixing matrices both for fermions and\nscalars in general cases, at the one-loop level. We then show that this gauge\ndependence can be avoided by fixing the counterterms for the mixing matrices in\nterms of the off-diagonal wave function corrections for fermions and scalars\nafter a rearrangement, in a similar manner to the pinch technique for gauge\nbosons. We finally present explicit calculation of the gauge dependence for two\ncases: CKM matrix in the Standard Model, and left-right mixing of scalar quarks\nin the minimal supersymmetric standard model.", "category": "hep-ph" }, { "text": "Distinguishing magnetic moment from oscillation solutions of the solar\n neutrino problem with Borexino: Assuming that the observed deficit of solar neutrinos is due to the\ninteraction of their transition magnetic moment with the solar magnetic field\nwe derive the predictions for the forthcoming Borexino experiment. Three\ndifferent model magnetic field profiles which give very good global fits of the\ncurrently available solar neutrino data are used. The expected signal at\nBorexino is significantly lower than those predicted by the LMA, LOW and VO\nneutrino oscillation solutions of the solar neutrino problem. It is similar to\nthat of the SMA oscillation solution which, however, is strongly disfavoured by\nthe Super-Kamiokande data on day and night spectra and zenith angle\ndistribution of the events. Thus, the neutrino magnetic moment solution of the\nsolar neutrino problem can be unambiguously distinguished from the currently\nfavoured oscillation solutions at Borexino.", "category": "hep-ph" }, { "text": "Heavy hybrid mesons in the QCD sum rule: We study the spectra of the hybrid mesons containing one heavy quark\n($q\\bar{Q}g$) within the framework of QCD sum rules in the heavy quark limit.\nThe derived sum rules are stable with the variation of the Borel parameter\nwithin their corresponding working ranges. The extracted binding energy for the\nheavy hybrid doublets $H^h(S^h)$ and $M^h(T^h)$ is almost degenerate. We also\ncalculate the pionic couplings between these heavy hybrid and the conventional\nheavy meson doublets using the light-cone QCD sum rule method. The extracted\ncoupling constants are rather small as a whole. With these couplings we make a\nrough estimate of the partial widths of these pionic decay channels.", "category": "hep-ph" }, { "text": "MSSM at future Higgs factories: In this work, we study the implication of Higgs precision measurements at\nfuture Higgs factories on the MSSM parameter space, focusing on the dominant\nstop sector contributions. We perform a multi-variable fit to both the signal\nstrength for various Higgs decay channels at Higgs factories and the Higgs\nmass. The chi-square fit results show sensitivity to mA, tan beta, stop mass\nparameter mSUSY as well as the stop left-right mixing parameter Xt. We also\nstudy the impact of the Higgs mass prediction on the MSSM and compare the\nsensitivities of different Higgs factories.", "category": "hep-ph" }, { "text": "Test of beta and antineutrino spectra symmetry in beta-decay: The mechanism of beta decay in nature is not understood yet. Mirrored energy\nspectra of electron and antineutrino can clarify the situation. A special\nexperiment is needed to measure antineutrino spectrum from known beta-decaying\nisotope to compare it with the beta one. One of ongoing experiments with large\nvolume detector can be chosen to make the experiment. Another possibility is to\nmake a special experiment close to a powerful source of mixture of known\nbeta-decaying isotopes. If sufficient differences in shape will be observed the\nmethod of antineutrino spectrum calculation should be revised.", "category": "hep-ph" }, { "text": "Color-Octet $\u03c8'$ Production at Low $p_\\perp$: We study contributions from color-octet quarkonium formation mechanisms to\n$p_\\perp$-integrated $\\psi'$ production cross sections in pion-nucleon\nreactions. The observed polarization of the $\\psi'$ is not reproduced by the\nlowest-order leading-twist color-singlet and color-octet mechanisms. This\nsuggests that there are important quarkonium production mechanisms beyond\nleading twist.", "category": "hep-ph" }, { "text": "B-Mesons on the Transverse Lattice: We present results from a first study of $B$-mesons that is based on a\ntransverse lattice formulation of light-front QCD. The shape of the Isgur-Wise\nform factor is in very good agreement with experimental data. However, the\ncalculations yield rather large values for $f_B$ and $\\bar{\\Lambda}$ compared\nto contemporary calculations based on other techniques.", "category": "hep-ph" }, { "text": "Seesaw and the Riddle of Mass: The prediction of small neutrino masses through the Seesaw Mechanism and\ntheir subsequent measurement suggests that the natural cut-off of the Standard\nModel is very high indeed. The recent neutrino data must be interpreted as a\nreflection of physics at very high energy. We examine their implications in\nterms of ideas of Grand Unification and Supersymmetry, and as possible hints\nfor a unified theory of flavor.", "category": "hep-ph" }, { "text": "Neutrino Oscillometry: Neutrino oscillations are studied employing sources of low energy\nmonoenergetic neutrinos following electron capture by the nucleus and measuring\nelectron recoils. Since the neutrino energy is very low the oscillation length\nappearing in this electronic neutrino disappearance experiment can be so small\nthat the full oscillation can take place inside the detector. Thus one may\ndetermine very accurately all the neutrino oscillation parameters. In\nparticular one can measure or set a better limit on the unknown parameter\ntheta13. One, however, has to pay the price that the expected counting rates\nare very small. Thus one needs a very intensive neutrino source and a large\ndetector with as low as possible energy threshold and high energy and position\nresolution. Both spherical gaseous and cylindrical liquid detectors are\nstudied. Different source candidates are considered", "category": "hep-ph" }, { "text": "Jet grooming through reinforcement learning: We introduce a novel implementation of a reinforcement learning (RL)\nalgorithm which is designed to find an optimal jet grooming strategy, a\ncritical tool for collider experiments. The RL agent is trained with a reward\nfunction constructed to optimize the resulting jet properties, using both\nsignal and background samples in a simultaneous multi-level training. We show\nthat the grooming algorithm derived from the deep RL agent can match\nstate-of-the-art techniques used at the Large Hadron Collider, resulting in\nimproved mass resolution for boosted objects. Given a suitable reward function,\nthe agent learns how to train a policy which optimally removes soft wide-angle\nradiation, allowing for a modular grooming technique that can be applied in a\nwide range of contexts. These results are accessible through the corresponding\nGroomRL framework.", "category": "hep-ph" }, { "text": "Polarization puts a New Spin on Physics: Polarization and spin effects are useful for probing the Standard Model, in\nboth the electroweak sector and the strong sector, where the spin decomposition\nof the nucleon is still a hot topic, with important new data on the net\npolarizations of the gluon and the strange quarks. Spin phenomena are also\nuseful in searches for new physics, for example via measurements of the\nanomalous magnetic moment of the muon and searches for electric dipole moments.\nThe cross sections for the direct detection of dark matter may also have an\nimportant spin-dependent component, related to the spin decomposition of the\nnucleon, that could be an important diagnostic tool. Polarization effects are\nalso important diagnostic aids for high-energy experiments at electron-proton,\nproton-proton and electron-positron colliders.", "category": "hep-ph" }, { "text": "High energy photon production in strong colliding laser beams: The collision of two intense, low-frequency laser beams is considered. The\n$e^-e^+$ pairs created in this field are shown to exhibit recollisions, which\ntake place at high energy accumulated due to the wiggling of fermions. The\nresulting $e^-e^+$ annihilation produces high energy photons, or heavy\nparticles. The coherent nature of the laser field provides strong enhancement\nof the probability of these events. Analytical and numerical results are\noutlined.", "category": "hep-ph" }, { "text": "Out-of-Equilibrium Photon Production in the Late Stages of Relativistic\n Heavy-Ion Collisions: In this work, we assess the importance of non-equilibrium dynamics in the\nproduction of photons from the late stages of relativistic heavy-ion\ncollisions. The p$_\\mathrm{T}$-differential spectra and $v_2$ of photons from\nthe late hadronic stage are computed within a non-equilibrium hadron transport\napproach, and compared to the results of a local equilibrium evolution using\nideal relativistic hydrodynamics. It is found that non-equilibrium dynamics\nenhance the late-stage photon production at low p$_\\mathrm{T}$ and decreases it\nat higher p$_\\mathrm{T}$ compared to the estimate from hydrodynamics. This same\ncomparison points to a significant increase in the momentum anisotropies of\nthese photons due to non-equilibrium dynamics. Once combined with photons\nproduced above the particlization temperature in the hydrodynamics evolution,\nthe differences between the two approaches appear modest in what concerns the\np$_\\mathrm{T}$ differential spectra, but are clearly noticeable at low\np$_\\mathrm{T}$ for the elliptic flow: non-equilibrium dynamics enhance the\nphoton $v_2$ below p$_\\mathrm{T}$ $\\approx 1.4$ GeV.", "category": "hep-ph" }, { "text": "Measuring Slepton Masses and Mixings at the LHC: Flavor physics may help us understand theories beyond the standard model. In\nthe context of supersymmetry, if we can measure the masses and mixings of\nsleptons and squarks, we may learn something about supersymmetry and\nsupersymmetry breaking. Here we consider a hybrid gauge-gravity supersymmetric\nmodel in which the observed masses and mixings of the standard model leptons\nare explained by a U(1) x U(1) flavor symmetry. In the supersymmetric sector,\nthe charged sleptons have reasonably large flavor mixings, and the lightest is\nmetastable. As a result, supersymmetric events are characterized not by missing\nenergy, but by heavy metastable charged particles. Many supersymmetric events\nare therefore fully reconstructible, and we can reconstruct most of the charged\nsleptons by working up the long supersymmetric decay chains. We obtain\npromising results for both masses and mixings, and conclude that, given a\nfavorable model, precise measurements at the LHC may help shed light not only\non new physics, but also on the standard model flavor parameters.", "category": "hep-ph" }, { "text": "Photoproduction of Vector Mesons at Large Transfer: At forward angles, the cross-sections of photoproduction of vector mesons\n($\\rho$, $\\omega$, and $\\phi$) are well accounted for by the exchange of the\nPomeron at high energies, while contributions of $t$ channel exchange of\nReggeons are significant at low energies. At large angles, the impact parameter\nbecomes small enough to prevent their constituents to build up the exchanged\nReggeons or Pomeron. Two gluon exchange appears to dominate above $-t\\simeq 1$\nGeV$^2$, especially in the $\\phi$ channel.", "category": "hep-ph" }, { "text": "Analysis of the decay constants of the heavy pseudoscalar mesons with\n QCD sum rules: In this article, we recalculate the contributions of all vacuum condensates\nup to dimension-6, in particular the one-loop corrections to the quark\ncondensates $\\alpha_s<\\bar{q}q>$ and partial one-loop corrections to the\nfour-quark condensates $\\alpha_s^2<\\bar{q}q>^2$, in the operator product\nexpansion. Then we study the masses and decay constants of the heavy\npseudoscalar mesons $D$, $D_s$, $B$ and $B_s$ using the QCD sum rules with two\nchoices: {\\bf I} we choose the $\\bar{MS}$ masses by setting $m=m(\\mu)$ and take\nperturbative corrections up to the order $\\mathcal{O}(\\alpha_s)$; {\\bf II} we\nchoose the pole masses $m$, take perturbative corrections up to the order\n$\\mathcal{O}(\\alpha_s^2)$ and set the energy-scale to be the heavy quark pole\nmass $\\mu=m_Q$. In the case of {\\bf I}, the predictions\n$f_D=(208\\pm11)\\,\\rm{MeV}$ and $f_B=(189\\pm15)\\,\\rm{MeV}$ are consistent with\nthe experimental data within uncertainties, while the prediction\n$f_{D_s}=(241\\pm12)\\,\\rm{MeV}$ is below the lower bound of the experimental\ndata $f_{D_s}=(260.0\\pm5.4)\\,\\rm{MeV}$. In the case of {\\bf II}, the\npredictions $f_D=(211\\pm14)\\,\\rm{MeV}$, $f_B=(190\\pm17)\\,\\rm{MeV}$,\n$f_{D_s}=(258\\pm13)\\,\\rm{MeV}$ and $f_{D_s}/f_D=1.22\\pm0.08$ are all in\nexcellent agreements with the experimental data within uncertainties.", "category": "hep-ph" }, { "text": "Threshold behavior of Feynman diagrams: the master two-loop propagator: An asymptotic expansion of the two-loop two-point ``master'' diagram with two\nmasses $m$ and $M$, on the mass shell $Q^2=M^2$, is presented. The treatment of\nthe non-analytical terms arising in the expansion around the branching point is\ndiscussed. Some details of the calculation of a new class of two-loop integrals\nare given.", "category": "hep-ph" }, { "text": "Virtual Corrections to the NLO Splitting Functions for Monte Carlo: the\n non-singlet case: Construction of a QCD cascade at the NLO level requires recalculation of the\nsplitting functions in a different manner [1]. We describe the calculation of\nsome of the virtual contributions to the non-singlet splitting function. In\norder to be compatible with the earlier calculated real contributions [2], the\nprincipal value prescription for regularizing the infrared singularities must\nbe used in a new way. We illustrate this new scheme on simple examples. For the\ncalculations we wrote a Mathematica package called Axiloop. We describe its\ncurrent status.", "category": "hep-ph" }, { "text": "Induced top Yukawa coupling and suppressed Higgs mass parameters: In the scenarios with heavy top squarks, mass parameters of the Higgs field\nmust be fine-tuned due to a large logarithmic correction to the soft scalar\nmass. We consider a new possibility that the top Yukawa coupling is small above\nTeV scale. The large top mass is induced from strong Yukawa interaction of the\nHiggs with another gauge sector, in which supersymmetry breaking parameters are\ngiven to be small. Then it is found that the logarithmic correction to the\nHiggs soft scalar mass is suppressed in spite of the strong coupling and the\nfine-tuning is ameliorated. We propose an explicit model coupled to a\nsuperconformal gauge theory which realizes the above situation.", "category": "hep-ph" }, { "text": "DUNE potential as a New Physics probe: Neutrino experiments, in the next years, aim to determine with precision all\nthe six parameters of the three-neutrino standard paradigm. The complete\nsuccess of the experimental program is, nevertheless, attached to the\nnon-existence (or at least smallness) of Non-Standard Interactions (NSI). In\nthis work, anticipating the data taken from long-baseline neutrino experiments,\nwe map all the weakly coupled theories that could induce sizable NSI, with the\npotential to be determined in these experiments, in particular DUNE. Once\npresent constraints from other experiments are taken into account, in\nparticular charged-lepton flavor violation, we find that only models containing\nleptoquarks (scalar or vector) and/or neutral isosinglet vector bosons are\nviable. We provide the explicit matching formulas connecting weakly coupled\nmodels and NSI, both in propagation and production. Departing from the weakly\ncoupled completion with masses at TeV scale, we also provide a global fit on\nall NSI for DUNE, finding that NSI smaller than $10^{-2}$ cannot be probed even\nin the best-case scenario.", "category": "hep-ph" }, { "text": "Partonic structure of the virtual photon: Interactions of virtual photons are analyzed in terms of their parton\ndistribution functions. It is shown that the concept of parton distribution\nfunctions is phenomenologically very useful even for highly virtual photonds\ninvolved in hard collisions. The role of the longitudinal photons for proper\ninterpretation of the data on jet cross--sections in the region of moderate\nphoton virtualities accessible at HERA is explored.", "category": "hep-ph" }, { "text": "Inelastic dark matter nucleus scattering: Direct detection experiments aim at the detection of dark matter in the form\nof weakly interacting massive particles (WIMPs) by searching for signals from\nelastic dark matter nucleus scattering. Additionally, inelastic scattering in\nwhich the nucleus is excited is expected from nuclear physics and provides an\nadditional detectable signal. In the context of a low-energy effective field\ntheory we investigate the experimental reach to these inelastic transitions for\nxenon-based detectors employing a dual-phase time projection chamber. We find\nthat once a dark matter signal is established, inelastic transitions enhance\nthe discovery reach and we show that they allow a better determination of the\nunderlying particle physics.", "category": "hep-ph" }, { "text": "Hard spectator-scattering in B -> pi pi decays at NNLO: We compute the 1-loop (NNLO) corrections to hard spectator-scattering in\ntree-dominated hadronic B decays. Depending on the values of hadronic input\nparameters the corrections are shown to have a significant impact on the B ->\npi pi branching fractions.", "category": "hep-ph" }, { "text": "Dilaton Stabilisation in $D$-term Inflation: Dilaton stabilisation is usually considered to pose a serious obstacle to\nsuccessful $D$-term inflation in superstring theories. We argue that the\nphysics of gaugino condensation is likely to be modified during the\ninflationary phase in such a way as to enhance the gaugino condensation scale.\nThis enables dilaton stabilisation during inflation with the $D$-term still\ndominating the vacuum energy at the stable minimum.", "category": "hep-ph" }, { "text": "Bell's Inequality and $\u03c4$-Physics at LEP: In this talk given at the TAU92 Workshop, Columbus, OH, Sept. 92, we\nsummarize results presented in more detail in a recent paper by S. Abel, M.\nDittmar and the author where we gave a general proof that Bell's inequality can\nnot be tested at a collider experiment. In particular, a measurement of\ncorrelated tau-spins at LEP does not constitute a test of local realistic\ntheories via Bell's inequality. The central point of the argument is that such\ntests, where the spins of two particles are inferred from a scattering\ndistribution, can always be described by a local hidden variable theory. In\nresponse to questions at the workshop we go beyond the paper and show that an\nold experiment involving the measurement of the correlated spins of the two\nphotons emitted in positronium decay via Compton-scattering is also not a\nviable test of Bell's inequality.", "category": "hep-ph" }, { "text": "Neutrino induced meson productions in forward limit: We study neutrino-induced meson productions off the nucleon in the forward\nlimit by applying the PCAC hypothesis to our dynamical coupled-channels (DCC)\nmodel. The DCC model reasonably describes pi N, gamma N -> pi N, eta N, K\nLambda, K Sigma data in the resonance region. We give a prediction for nu N ->\npi N, pi pi N, eta N, K Lambda, K Sigma$ reactions cross sections. We compare\nour results with those from the Rein-Sehgal model, and find a significant\ndifference.", "category": "hep-ph" }, { "text": "The linear BESS model and the double Higgs-strahlung production: In this paper we evaluate, in the context of the linear BESS model the\ncross-section for the double Higgs-strahlung process. We find that, within the\nbounds given by the actual experimental data, significant deviations with\nrespect to the SM may arise. In the linear BESS model not only the\nself-couplings of the Higgs are modified, but also the Z-Higgs couplings. We\nthink that this is a generic feature of any extension of the SM and, in our\nopinion, it should be kept in mind in analyzing the future data on the process\nstudied here.", "category": "hep-ph" }, { "text": "Density spikes near black holes in self-interacting dark matter halos\n and indirect detection constraints: Self-interacting dark matter (SIDM) naturally gives rise to a cored\nisothermal density profile, which is favored in observations of many dwarf\ngalaxies. The dark matter distribution in the presence of a central black hole\nin an isothermal halo develops a density spike with a power law of $r^{-7/4}$,\nwhich is shallower than $r^{-7/3}$ as expected for collisionless dark matter\n(CDM). Thus, indirect detection constraints on dark matter annihilations from\nthe density spike could be relaxed in SIDM. Taking the most dense satellite\ngalaxy of the Milky Way Draco as an example, we derive upper limits on the\nannihilation cross section and the black hole mass for both SIDM and CDM halos.\nFor the former case, Draco could host an intermediate mass black hole even if\ndark matter is composed of thermal relics. We further explore the constraints\nfrom the Milky Way and M87, which host supermassive black holes, and show the\nupper limits on the annihilation cross section are significantly weakened in\nSIDM. Our results also indicate that the Event Horizon Telescope could provide\na unique test of SIDM spikes.", "category": "hep-ph" }, { "text": "Weak Radiative Hyperon Decays in Chiral Perturbation Theory: The parity-conserving $a$ and parity-violating $b$ amplitudes for weak\nradiative hyperon decay are studied using chiral perturbation theory. The\nimaginary parts of $a$ and $b$ are computed using unitarity. The real part of\n$b$ is dominated by a one-loop infrared divergent graph which is computed. The\nreal part of $a$ has a large theoretical uncertainty and cannot be calculated\nreliably. Counterterms for the $a$ and $b$ amplitudes are classified using\n$CPS$ symmetry. The experimental values for decay widths and asymmetries are\nconsistent with theory, with the exception of the asymmetry parameter for the\n$\\Sigma^+ \\rightarrow p \\gamma$ decay.", "category": "hep-ph" }, { "text": "Report of the Topical Group on Cosmic Probes of Dark Matter for Snowmass\n 2021: Cosmological and astrophysical observations currently provide the only\nrobust, positive evidence for dark matter. Cosmic probes of dark matter, which\nseek to determine the fundamental properties of dark matter through\nobservations of the cosmos, have emerged as a promising means to reveal the\nnature of dark matter. This report summarizes the current status and future\npotential of cosmic probes to inform our understanding of the fundamental\nnature of dark matter in the coming decade.", "category": "hep-ph" }, { "text": "First exotic hadron with open heavy flavor: $cs\\bar u\\bar d$ tetraquark: The LHCb Collaboration has reported resonant activity in the channel $D^+\nK^-$, identifying two components: $X_0(2900)$ with $J^P = 0^+$ at $2866 {\\pm}\n7$ MeV, $\\Gamma_0=57{\\pm} 13$ MeV and $X_1(2900)$ with $J^P = 1^-$ at $2904\n{\\pm} 7$ MeV, $\\Gamma_1=110{\\pm} 12$ MeV. We interpret the $X_0(2900)$\ncomponent as a $cs \\bar u\\bar d$ isosinglet compact tetraquark, calculating its\nmass to be $2863 {\\pm} 12$ MeV. This is the first exotic hadron with open heavy\nflavor. The analogous $bs\\bar u\\bar d$ tetraquark is predicted at $6213 {\\pm}\n12$ MeV. We discuss possible interpretations of the heavier and wider\n$X_1(2900)$ state and examine potential implications for other systems with two\nheavy quarks.", "category": "hep-ph" }, { "text": "Investigating $R_D$ and $R_{D^*}$ anomalies in a Left-Right model with\n an Inverse Seesaw: We investigate $R_D$ and $R_{D^*}$ anomalies in a low scale left-right\nsymmetric model based on $SU(3)_C\\times SU(2)_L\\times SU(2)_R\\times\nU(1)_{B-L}\\times Z_2$ with a simplified Higgs sector consisting of only one\nbidoublet and one $SU(2)_R$ doublet. The Wilson coefficients relevant to the\ntransition $b\\to c\\tau \\nu$ are derived by integrating out the charged Higgs\n$H^\\pm$ boson, which gives the dominant contributions. We emphasize that the\ncharged Higgs effects, with the complex right-handed quark mixing matrix, can\naccount for both $R_D$ and $R_{D^*}$ anomalies simultaneously, while adhering\nto the constraints from ${\\rm BR}(B^-_c \\to \\tau^- \\bar{\\nu}_\\tau) $.", "category": "hep-ph" }, { "text": "Phase Transition to RS: Cool, not Supercool: Motivated by the warped conifold compactification, we model the infrared (IR)\ndynamics of confining gauge theories in a Randall-Sundrum (RS)-like setup by\nmodifying the stabilizing Goldberger-Wise (GW) potential so that it becomes\nlarge (in magnitude) in the IR and back-reacts on the geometry. We study the\nhigh-temperature phase by considering a black brane background in which we\ncalculate the entropy and free energy of the strongly back-reacted solution. As\nwith Buchel's result for the conifold (arXiv:2103.15188), we find a minimum\ntemperature beyond which the black brane phase is thermodynamically unstable.\nIn the context of a phase transition to the confining background, our results\nsuggest that the amount of supercooling that the metastable black brane phase\nundergoes can be limited. It also suggests the first-order phase transition\n(and the associated gravitational waves from bubble collision) is not\nuniversal. Our results therefore have important phenomenological implications\nfor early universe model building in these scenarios.", "category": "hep-ph" }, { "text": "Phenomenology of the BFKL pomeron and Unitarity Corrections at low x: The low $x$ limit of deep inelastic electron proton scattering is considered\nusing methods of perturbative QCD. In the first part we investigate the\nphenomenological consequences of the resummation of leading logarithms in $1/x$\ngiven by the BFKL pomeron. We apply the BFKL pomeron to the inclusive structure\nfunction $F_2$, to the diffractive production of vector mesons at large\nmomentum transfer, to inclusive photon diffractive dissociation in DIS and to\nquark-antiquark production with large transverse momenta in DIS diffractive\ndissociation. For the last process we perform extensive numerical calculations\nbased on the double logarithmic approximation. The BFKL pomeron is known to\nviolate unitarity. In the second part the first next-to-leading corrections\nwhich have to be taken into account to restore unitarity of the scattering\namplitude are investigated. A compact configuration space representation of the\ntwo to four gluon transition vertex is derived. Conformal symmetry of the\nvertex is proven and its relation to a conformal covariant three point function\nis established. The important role of the spectral function $\\chi_4$ of the\nfour gluon state is pointed out. We relate this function to the twist expansion\nof the four gluon amplitude. Motivated by this relation we develop a method to\nperform the twist expansion of the amplitude. Based upon first results of our\nanalysis we draw conclusions concerning the singularity structure of the\nfunction $\\chi_4$.", "category": "hep-ph" }, { "text": "Probing neutrino magnetic moment and unparticle interactions with\n Borexino: We discuss the limits on the neutrino magnetic moment and hypothetical\ninteractions with a hidden unparticle sector, coming from the first neutrino\ndata release of the Borexino experiment. The observed spectrum in Borexino\ndepends weakly on the solar model used in the analysis, since most of the\nsignal comes from the mono-energetic 7Be neutrinos. This fact allows us to\ncalibrate the nu-e scattering cross section through the spectral shape. In this\nway, we have derived a limit on the magnetic moment for the neutrinos coming\nfrom the Sun (in which a nu_mu and nu_tau component is present): mu_nu<8.4E-11\nmu_B (90%CL) which is comparable with those obtained from low energy reactor\nexperiments. Moreover, we improve the previous upper limit on magnetic moment\nof the nu_tau by three orders of magnitude and the limit on the coupling\nconstant of the neutrino with a hidden unparticle sector.", "category": "hep-ph" }, { "text": "Chiral Phase Transition in QCD and Vector Manifestation: Spontaneous chiral symmetry breaking is one of the most important features in\nlow-energy QCD. The chiral symmetry is expected to be restored at very high\ntemperature and/or density. Accompanied by the chiral phase transition,\nproperties of hadrons will be changed especially near the critical point. The\nstudy of the phenomena associated with the chiral phase transition will give us\nsome clues on the connection between the chiral symmetry and the low-energy\nhadron dynamics.\n We develop the theory based on the hidden local symmetry (HLS) at finite\ntemperature, which is an effective field theory of QCD and includes pions and\nvector mesons as the dynamical degrees of freedom, and study the chiral phase\ntransition in hot matter. We show that the chiral symmetry is restored as the\nvector manifestation (VM), in which the massless degenerate pion (and its\nflavor partners) and the longitudinal $\\rho$ meson (and its flavor partners) as\nthe chiral partner. We also present several predictions based on the VM. We\nestimate the critical temperature $T_c$ and show the following phenomena near\n$T_c$: the vector charge susceptibility becomes equal to the axial-vector\ncharge susceptibility; the vector dominance of the electromagnetic form factor\nof the pion is largely violated; the pion velocity is close to the speed of\nlight. Furthermore, we show that the remnant of the VM can be clearly seen in\nthe system of heavy mesons. We expect that the VM and its predictions are\ntestable by current and future experiments and the lattice analysis.", "category": "hep-ph" }, { "text": "Probing a new decay of vector-like top partner mediated by heavy\n Majorana neutrino via single production: Models beyond the Standard Model have been proposed to simultaneously solve\nthe problems of naturalness and neutrino mass, in which heavy Majorana\nneutrinos and vector-like top partners are usually predicted. A new decay\nchannel of the top partner mediated by the heavy Majorana neutrino can thus\nappear: $T\\to b\\,W^{+}\\to b\\,\\ell^{+}\\ell^{+}q\\bar{q'}$. We study in this paper\nthe observability of this decay process through single production of the top\npartner at the 14 TeV LHC: $pp\\to T/\\bar{T}$+jets$\\to\nb/\\bar{b}+\\mu^{\\pm}\\mu^{\\pm}$+jets. $2\\sigma$ exclusion bounds on the top\npartner mass and mixing parameters are given by Monte-Carlo simulation, which\nsurpass those from the search through VLT pair production in the mass range of\n$m_{T}>1.3$ TeV.", "category": "hep-ph" }, { "text": "Effects of lepton number violating interactions on $t \\bar t$ production\n at NLC: We discuss the effects of lepton number violating interactions namely,\nR-parity violation and leptoquarks on top quark pair production at the upcoming\n$e^+ e^-$ linear colliders. Effects of SU(2) singlet, doublet and triplet\nleptoquark interactions are investigated. R-parity violating minimal\nsupersymmetric standard model also allows certain kinds of lepton number\nviolating interactions which are same as singlet leptoquarks with left-handed\ninteractions. We have calculated the cross-section of $e^+ e^- \\to t \\bar t$ in\npresence of the above interactions. With conservative values of lepton number\nviolating coupling strengths we got enhancement of top-pair production\ncross-section in all of the above cases.", "category": "hep-ph" }, { "text": "Scaling law for the $\u03a5(4S) \\to B \\bar B$ and $\u03c8(3770) \\to D\n \\bar D$ decay constants from effective sum rules: Sum rules for exclusive production of heavy meson pairs in $e^+e^-$\nannihilation are used to evaluate the $\\Upsilon(4S) \\to B \\bar B$ and\n$\\psi(3770) \\to D \\bar D$ decay widths. Infinitely heavy quark limit is\ndiscussed, so that scaling law for the quarkonium-meson coupling constant is\nderived. A value of the $B\\bar B$ pair contribution into the leptonic constant\n$f_{\\Upsilon(4S)}$ is estimated.", "category": "hep-ph" }, { "text": "Branching ratios of $B_s\\to (K^+K^-,K^0\\bar{K}^0)$ and $B_d\\to \u03c0^+\n \u03c0^- and determination of \\boldmath{$\u03b3(\u03c6_3)$: We explored various cases for the branching ratios (BRs) of $B_s\\to K^+K^-$,\n$B_s\\to K^0\\bar{K}^0$ and $B_d\\to \\pi^+ \\pi^-$ decays. We study the possibility\nof determining $\\gamma $ by using the following the measurements: (a) BRs of\n$B_s\\to K^+K^-$, and $B_s\\to K^0\\bar{K}^0$; (b) the ratio of direct CP\nasymmetries in $B_d\\to \\pi^+ \\pi^-$ and $B_s\\to K^+K^-$; (c) the mix-induced CP\nasymmetry in $B_d\\to \\pi^+ \\pi^-$; and (d) the angle of $\\beta$.", "category": "hep-ph" }, { "text": "Top quark asymmetry and dijet resonances: CDF recently reported an anomaly in the $m_{jj}$ distribution of dijet events\nproduced in association with a $W$ boson. If this anomaly is associated with a\nnew flavor conserving vector resonance, $V$, one might have expected to observe\neffects in the analogous $m_{jj}$ distribution produced in association with a\n$\\gamma$. No such excess is observed. A single $u-t-V$ flavor changing\ncoupling, however, can contribute to the $m_{jj}$ anomaly while being\nconsistent with other resonance searches. Furthermore, it gives a potential\nexplanation of the observed forward-backward asymmetry in top quark production.", "category": "hep-ph" }, { "text": "NLO QCD Predictions for associated t-tbar-h production in Hadronic\n Collisions: We present the next-to-leading-order (NLO) QCD corrections to the inclusive\ntotal cross section for the production of a Higgs boson in association with a\ntop anti-top quark pair within the Standard Model at the Tevatron and the LHC.", "category": "hep-ph" }, { "text": "Calculation of the scattering amplitudes: General equations for the calculation of amplitudes are presented. As an\nillustration of application of proposed formulae we calculate electron-electron\nscattering amplitudes.", "category": "hep-ph" }, { "text": "Manifestaion of SUSY in B decays: SUSY effects on various flavor changing neutral current processes are\ndiscussed in the minimal supergravity model and the SU(5) grand unified theory\nwith right-handed neutrino supermultiplets. In particular, in the latter case\nthe neutrino Yukawa coupling constants can be a source of the flavor mixing in\nthe right-handed-down-type-squark sector. It is shown that due to this mixing\nthe time-dependent CP asymmetry of radiative B decay can be as large as 30% and\nthe ratio of $B_s$-$\\bar{B}_s$ mixing and $B_d$-$\\bar{B}_d$ mixing deviates\nfrom the prediction in the standard model and the minimal supergravity model\nwithout the neutrino interaction.", "category": "hep-ph" }, { "text": "Pseudoscalar--meson decuplet--baryon coupling constants in light cone\n QCD: Taking into account the $SU(3)_f$ breaking effects, the strong coupling\nconstants of the $\\pi$, $K$ and $\\eta$ mesons with decuplet baryons are\ncalculated within light cone QCD sum rules method. It is shown that all\ncoupling constants, even in the case of $SU(3)_f$ breaking, are described in\nterms of only one universal function. It is shown that for $\\Xi^{\\ast 0} \\to\n\\Xi^{\\ast 0} \\eta $ transition violation of $SU(3)_f$ symmetry is very large\nand for other channels when $SU(3)_f$ symmetry is violated, its maximum value\nconstitutes $10%\\div15%$.", "category": "hep-ph" }, { "text": "The QCD phase structure at finite temperature and density: We discuss the phase structure of QCD for $N_f=2$ and $N_f=2+1$ dynamical\nquark flavours at finite temperature and baryon chemical potential. It emerges\ndynamically from the underlying fundamental interactions between quarks and\ngluons in our work. To this end, starting from the perturbative high-energy\nregime, we systematically integrate-out quantum fluctuations towards low\nenergies by using the functional renormalisation group. By dynamically\nhadronising the dominant interaction channels responsible for the formation of\nlight mesons and quark condensates, we are able to extract the phase diagram\nfor $\\mu_B/T \\lesssim 6$. We find a critical endpoint at\n$(T_\\text{CEP},{\\mu_B}_{\\text{CEP}})=(107, 635)\\,\\text{MeV}$. The curvature of\nthe phase boundary at small chemical potential is $\\kappa=0.0142(2)$, computed\nfrom the renormalised light chiral condensate $\\Delta_{l,R}$. Furthermore, we\nfind indications for an inhomogeneous regime in the vicinity and above the\nchiral transition for $\\mu_B\\gtrsim 417$ MeV. Where applicable, our results are\nin very good agreement with the most recent lattice results. We also compare to\nresults from other functional methods and phenomenological freeze-out data.\nThis indicates that a consistent picture of the phase structure at finite\nbaryon chemical potential is beginning to emerge. The systematic uncertainty of\nour results grows large in the density regime around the critical endpoint and\nwe discuss necessary improvements of our current approximation towards a\nquantitatively precise determination of QCD phase diagram.", "category": "hep-ph" }, { "text": "Gauge Dependence of Four-Fermion QED Green Function and Atom-Like Bound\n State Calculations: We derive a relation between four-fermion QED Green functions of different\ncovariant gauges which defines the gauge dependence completely. We use the\nderived gauge dependence to check the gauge invariance of atom-like bound state\ncalculations. We find that the existing QED procedure does not provide gauge\ninvariant binding energies. A way to a corrected gauge invariant procedure is\npointed out.", "category": "hep-ph" }, { "text": "Ernest Henley and the shape of baryons: Calculations of pion-baryon couplings, baryon quadrupole and octupole\nmoments, baryon spin and orbital angular momentum done in collaboration with\nErnest Henley are reviewed. A common theme of this work is the shape of\nbaryons. Also, a personal account of my work with Ernest Henley during the\nperiod 1999-2013 is given.", "category": "hep-ph" }, { "text": "Braaten-Pisarski Action, Disoriented Chiral Condensate, and Chiral\n Symmetry Non-Restoration: The QCD effective action at high T shows a manifest global chiral symmetry.\nAnd calculations show that the order parameter \\psibarpsi vanishes above T_c.\nIt has been popular to refer to this T_c as chiral symmetry restoration\ntemperature because it fits into our prejudice that chiral symmetry is like an\n`ordered' state, and at high T it must become disordered. In fact, NJL ground\nstate is not an ordered spin state. The recent scenario of a generic class of\ndisoriented chiral condensate offers an example where \\psibarpsi in each little\ndomain is nonzero, but the average over all space of \\psibarpsi vanishes. Such\na dcc ground state continues to break chiral invariance. But how do you\nreconcile this with the apparent chiral symmetry at high T? The\nBraaten-Pisarski action is a good laboratory to investigate the subtleties of\nhigh temperature chiral symmetry. By carrying out a canonical quantization of\nthis highly nonlocal action, I demonstrate how the thermal vacuum at high T\nconserves the new \\beta-chirality but breaks the old T=0 chirality. Lattice\ncalculations show that the pion develops a screening mass at high T. Our\ncontinuum field theory calculations show that the QCD pion remains massless for\nall T. I conclude the talk by showing how the hot pion manages to accomodate\nthe two results by propagating in the early universe with a halo.", "category": "hep-ph" }, { "text": "Can an invisible Higgs boson be seen via diffraction at the LHC?: We study the possibility of observing an `invisible' Higgs boson in central\nexclusive diffractive production at the LHC. We evaluate the cross section\nusing, as a simple example, the Standard Model with a heavy fourth generation,\nwhere the invisible decay mode $H \\to \\nu_4 \\bar{\\nu}_4$ dominates, with the\nheavy neutrino mass $M(\\nu_4) \\simeq 50$ GeV. We discuss the possible\nrequirements on trigger conditions and the background processes.", "category": "hep-ph" }, { "text": "MLAnalysis: An open-source program for high energy physics analyses: We present a python-based program for phenomenological investigations in\nparticle physics using machine learning algorithms, called \\verb\"MLAnalysis\".\nThe program is able to convert LHE and LHCO files generated by\n\\verb\"MadGraph5_aMC@NLO\" into data sets for machine learning algorithms, which\ncan analyze the information of the events. At present, it contains three\nmachine learning (ML) algorithms: isolation forest (IF) algorithm, nested\nisolation forest (NIF) algorithm, kmeans anomaly detection (KMAD), and some\nbasic functionality to analyze the kinematic features of a data set. Users can\nuse this program to improve the efficiency of searching for new physics\nsignals.", "category": "hep-ph" }, { "text": "On next to soft corrections to Drell-Yan and Higgs Boson productions: We present a framework that resums threshold enhanced large logarithms to all\norders in perturbation theory for the production of a pair of leptons in\nDrell-Yan process and of Higgs boson in gluon fusion as well as in bottom quark\nannihilation. We restrict ourselves to contributions from diagonal partonic\nchannels. These logarithms include the distributions $((1-z)^{-1}\n\\ln^i(1-z))_+$ resulting from soft plus virtual (SV) and the logarithms\n$\\ln^i(1-z)$ from next-to-SV (NSV) contributions. We use collinear\nfactorisation and renormalisation group invariance to achieve this. The former\nallows one to define a Soft-Collinear (SC) function which encapsulates soft and\ncollinear dynamics of the perturbative results to all orders in strong coupling\nconstant. The logarithmic structure of these results are governed by universal\ninfrared anomalous dimensions and process dependent functions of Sudakov\ndifferential equation that the SC satisfies. The solution to the differential\nequation is obtained by proposing an all-order ansatz in dimensional\nregularisation, owing to several state-of-the-art perturbative results\navailable to third order. The $z$ space solutions thus obtained provide an\nintegral representation to sum up large logarithms originating from both soft\nand collinear configurations, conveniently in Mellin $N$ space. We show that in\n$N$ space, tower of logarithms $a_s^n/N^\\alpha \\ln^{2n-\\alpha} (N),\na_s^n/N^\\alpha \\ln^{2n-1-\\alpha}(N) \\cdots $ etc for $\\alpha =0,1$ are summed\nto all orders in $a_s$.", "category": "hep-ph" }, { "text": "Threshold factorization of the Drell-Yan process at next-to-leading\n power: We present a factorization theorem valid near the kinematic threshold\n$z=Q^2/\\hat{s}\\to 1$ of the partonic Drell-Yan process $q\\bar q\\to\\gamma^*+X$\nfor general subleading powers in the $(1-z)$ expansion. We then consider the\nspecific case of next-to-leading power. We discuss the emergence of collinear\nfunctions, which are a key ingredient to factorization starting at\nnext-to-leading power. We calculate the relevant collinear functions at\n$\\mathcal{O}(\\alpha_s)$ by employing an operator matching equation and we\ncompare our results to the expansion-by-regions computation up to the\nnext-to-next-to-leading order, finding agreement. Factorization holds only\nbefore the dimensional regulator is removed, due to a divergent convolution\nwhen the collinear and soft functions are first expanded around $d=4$ before\nthe convolution is performed. This demonstrates an issue for threshold\nresummation beyond the leading-logarithmic accuracy at next-to-leading power.", "category": "hep-ph" }, { "text": "A Step Toward Model Comparison: Connecting Electroweak-Scale Observables\n to BSM through EFT and Bayesian Statistics: Recognizing the potential of effective field theories to posit multiple BSM\nscenarios in similar footing, with a possibility to compare them, we inspect\nthe effects of 11 single scalar-multiplet extensions of the SM on the combined\nset of electroweak precision observables and Higgs signal strength data, by\nsystematically integrating out the heavy multiplets and computing the resulting\nSMEFT operators and Wilson coefficients (WCs) up to one-loop level. Noting that\nmultiple BSM models give rise to a degenerate set of WCs, we then perform\nBayesian statistical inference both directly on the BSM parameters and on the\nassociated set of independent WCs. Using the posteriors of the BSM parameters,\nwe infer the respective (correlated) WC-distributions and compare both the\nmodel-independent and dependent analyses by overlaying the 2-D marginal\nWC-posteriors from both processes, thus laying the ground for a data-driven\nattempt to compare diverse BSM theories of different origins, and hopefully, a\npossible way to approach the intractable inverse problem. We also demonstrate,\nwith an example model, the crucial role of theoretical constraints to rule out\nlarge chunks of BSM parameter spaces. The entirety of numerical results is\navailable in GitHub.", "category": "hep-ph" }, { "text": "Phenomenological study of the anisotropic quark matter in the 2-flavor\n Nambu-Jona-Lasinio model: With the two flavor Nambu-Jona-Lasinio (NJL) model we carry out a\nphenomenological study on the chiral phase structure, mesonic properties and\ntransport properties in a momentum-space anisotropic quark matter. To calculate\ntransport coefficients we have utilized the kinetic theory in the relaxation\ntime approximation, where the momentum anisotropy is embedded in the estimation\nof both distribution function and the relaxation time. It is shown that an\nincrease of the anisotropy parameter $\\xi$ may results in a catalysis of chiral\nsymmetry breaking. The critical endpoint (CEP) is shifted to smaller\ntemperatures and larger quark chemical potentials as $\\xi $ increases, the\nimpact of momentum anisotropy on temperature of CEP is almost the same as that\non the quark chemical potential of CEP. The meson masses and the associated\ndecay widths also exhibit a significant $\\xi$ dependence. It is observed that\nthe temperature behavior of scaled shear viscosity $\\eta/T^3$ and scaled\nelectrical conductivity $\\sigma_{el}/T$ exhibit a similar dip structure, with\nthe minima of both $\\eta/T^3$ and $\\sigma_{el}/T$ shifting toward higher\ntemperatures with increasing $\\xi$. Furthermore, we demonstrate that the\nSeebeck coefficient $S$ decreases when temperature goes up and its sign is\npositive, indicating the dominant carriers for converting the temperature\ngradient to the electric field are up-quarks. The Seebeck coefficient $S$ is\nsignificantly enhanced with a large $\\xi$ for the temperature below the\ncritical temperature.", "category": "hep-ph" }, { "text": "Double-parton scattering effects in double charm production within gluon\n fragmentation scenario: We discuss charm $D^0 D^0$ meson-meson pair production in the forward\nrapidity region related to the LHCb experimental studies at $\\sqrt{s}$ = 7 TeV.\nWe consider double-parton scattering mechanisms of double $c \\bar c$ production\nand subsequent standard $cc \\to D^{0}D^{0}$ scale-independent hadronization as\nwell as new double $g$ and mixed $g c\\bar c $ production mechanisms with $gg\n\\to D^{0}D^{0}$ and $gc \\to D^{0}D^{0}$ scale-dependent hadronization. The new\nscenario with gluon fragmentation components results also in a new\nsingle-parton scattering mechanism of $gg$ production which is also taken here\ninto account. Results of the numerical calculations are compared with the LHCb\ndata for several correlation observables. The new mechanisms lead to a larger\ncross sections and to slightly different shapes of the calculated correlation\nobservables.", "category": "hep-ph" }, { "text": "DGLAP evolution for DIS diffraction production of high masses: In this paper we develop the DGLAP evolution for the system of produced\ngluons in the process of diffractive production in DIS, directly from the\nevolution equation in Color Glass Condensate approach. We are able to describe\nthe available experimental data with small value of the QCD coupling\n($\\bar{\\alpha_S} \\approx 0.1$). We conclude that in diffractive production, we\nhave a dilute system of emitted gluons and in the order to describe them, we\nneed to develop the next-to-leading order approach in perturbative QCD.", "category": "hep-ph" }, { "text": "Instanton induced transverse single spin asymmetry for $\u03c0^0$\n production in $pp$-scattering: We calculate the production cross-section and the transverse single-spin\nasymmetry for pion in $p^{\\uparrow}+p\\to \\pi^0 + X$. Our computation is based\non existence of the instanton induced effective quark-gluon and\nquark-gluon-pion interactions with a strong spin dependency. In this framework\nwe calculate the cross section without using fragmentation functions. We\ncompare predictions of the model with data from RHIC. Our numerical results,\nbased on the instanton liquid model for QCD vacuum, are in agreement with\nunpolarized cross section data. The asymmetry grows with the transverse\nmomentum of pion $k_t$ in accordance with experimental observations. It reach\nvalue $\\sim 10\\%$ but at higher $k_t$ than experiment shows.", "category": "hep-ph" }, { "text": "MicroBooNE and the $\u03bd_e$ Interpretation of the MiniBooNE Low-Energy\n Excess: A new generation of neutrino experiments is testing the $4.8\\sigma$ anomalous\nexcess of electron-like events observed in MiniBooNE. This is of huge\nimportance for particle physics, astrophysics, and cosmology, not only because\nof the potential discovery of physics beyond the Standard Model, but also\nbecause the lessons we will learn about neutrino-nucleus interactions will be\ncrucial for the worldwide neutrino program. MicroBooNE has recently released\nresults that appear to disfavor several explanations of the MiniBooNE anomaly.\nHere, we show quantitatively that MicroBooNE results, while a promising start,\nunquestionably do not probe the full parameter space of sterile neutrino models\nhinted at by MiniBooNE and other data, nor do they probe the $\\nu_e$\ninterpretation of the MiniBooNE excess in a model-independent way. Our analysis\ncode is fully available in\nhttps://github.com/Harvard-Neutrino/MicroBooNE-analysis-2021.", "category": "hep-ph" }, { "text": "Elliptic flow from color-dipole orientation in pp and pA collisions: For ultrarelativistic proton-proton and proton-nucleus collisions, we perform\nan exploratory study of the contribution to the elliptic flow $v_2$ coming from\nthe orientation of the momentum of the produced particles with respect to the\nreaction plane. Via the CGC factorization valid at high energies, this\ncontribution is related to the orientation of a color dipole with respect to\nits impact parameter, which in turn probes the transverse inhomogeneity in the\ntarget. Using the McLerran-Venugopalan model (with impact-parameter dependence)\nas an effective description for the soft gluon distribution in the (proton or\nnuclear) target, we present a semi-analytic calculation of the dipole\nscattering amplitude, including its angular dependence. We find that the\nangular dependence is controlled by soft gluon exchanges and hence is genuinely\nnon-perturbative. The effects of multiple scattering turn out to be essential\n(in particular, they change the sign of $v_2$). We find that sizable values for\n$v_2$, comparable to those observed in the LHC data and having a similar\ndependence upon the transverse momenta of the produced particles, can be easily\ngenerated via peripheral collisions. In particular, $v_2$ develops a peak at a\ntransverse momentum which scales with the saturation momentum in the target.", "category": "hep-ph" }, { "text": "Polarization in B->VV Decays: Factorizable amplitudes in B decays to light vector meson pairs give a\nlongitudinal polarization satisfying 1- f_L =O(1/m_b^2). This remains formally\ntrue when non-factorizable graphs are included in QCD factorization, and is\nnumerically realized in B->Rho Rho. In \\Delta S=1 decays a QCD penguin\nannihilation graph can effectively contribute at leading power to the\ntransverse and longitudinal amplitudes. The observed longitudinal polarization,\nf_L (B->phi K^*) \\approx 50%, can therefore be accounted for in the SM. The\nratio of perpendicular to parallel transverse rates provides a sensitive test\nfor new right-handed currents. The transverse b->sg dipole operator amplitudes\nare highly suppressed. CP violation measurements can therefore discriminate\nbetween new contributions to the dipole and four quark operators. SU(3)_F\nviolation in QCD penguin amplitudes can easily be O}(1), in general, due to\nannihilation. Implications for B->Rho K^* polarization and New Physics searches\nare pointed out.", "category": "hep-ph" }, { "text": "Four-Quark Mesons: The features of a model interpreting the light scalar mesons as\ndiquark-antidiquark bound states and the consequences of its natural extension\nto include heavy quarks are briefly reviewed.", "category": "hep-ph" }, { "text": "Hadrons on the worldline, holography, and Wilson flow: Holographic principles have impacted the way we look at strong coupling\nphenomena in quantum chromodynamics, strongly interacting extensions of the\nstandard model, and {condensed-matter} physics. In real world settings,\nhowever, we still lack understanding of why and when such an approach is\njustified. Therefore, here, without invoking any such principle a priori, we\ndemonstrate how such a picture arises in the worldline formulation of quantum\nfield theory. Among other connections to holographic models, a warped AdS5\ngeometry, a quantum mechanical picture, and hidden local symmetry emerge, as\nwell as a Wilson flow (gradient flow), which extends the four-dimensional\nsources to five-dimensional fields and a link to the Gutzwiller trace formula.\nThe worldline formulation also reproduces the non-relativistic case, which is\nimportant for condensed-matter physics.", "category": "hep-ph" }, { "text": "Reconciling sterile neutrinos with big bang nucleosynthesis: We re-examine the big bang nucleosynthesis (BBN) bounds on the mixing of\nneutrinos with sterile species. These bounds depend on the assumption that the\nrelic neutrino asymmetry $L_{\\nu}$ is very small. We show that for $L_{\\nu}$\nlarge enough (greater than about $10^{-5}$) the standard BBN bounds do not\napply. We apply this result to the sterile neutrino solution to the atmospheric\nneutrino anomaly and show that for $L_{\\nu} > 7 \\times 10^{-5}$ it is\nconsistent with BBN. The BBN bounds on sterile neutrinos mixing with electron\nneutrinos can also be weakened considerably.", "category": "hep-ph" }, { "text": "Discovery potential of the next-to-minimal supergravity-motivated model: Applying a likelihood analysis to the next-to-minimal supergravity-motivated\nmodel, we identify parameter space regions preferred by present experimental\nlimits from collider, astrophysical, and low energy measurements. We then show\nthat favored regions are amenable to detection by a combination of the CERN\nLarge Hadron Collider and an upgraded Cryogenic Dark Matter Search, provided\nthat the more than three sigma discrepancy in the difference of the\nexperimental and the standard theoretical values of the anomalous magnetic\nmoment of the muon prevails in the future.", "category": "hep-ph" }, { "text": "Amplitude Factorization in the Electroweak Standard Model: We lay out the basis of factorization at the amplitude level for processes\ninvolving the entire Standard Model. The factorization appears in a generalized\neikonal approximation in which we expand around a quasi-soft limit for massive\ngauge bosons, fermions, and scalars. We use the chirality-flow formalism\ntogether with a flow basis for isospin to express loop exchanges or emissions\nas operators in chirality and isospin flow. This forms the basis for amplitude\nevolution with parton exchange and branching in the full Standard Model,\nincluding the electroweak sector.", "category": "hep-ph" }, { "text": "An experiment to detect gravity at sub-mm scale with high-Q mechanical\n oscillators: Silicon double paddle oscillators are well suited for the detection of weak\nforces because of their high Q factor (about 10^5 at room temperature). We\ndescribe an experiment aimed at the detection of gravitational forces between\nmasses at sub-mm distance using such an oscillator. Gravitational excitation is\nproduced by a rotating aluminium disk with platinum segments. The force\nsensitivity of this apparatus is about 10 fN at room temperature for 1000 s\naveraging time at room temperature. The current limitations to detection of the\ngravitational force are mentioned.", "category": "hep-ph" }, { "text": "Vector-like quarks with non-renormalizable interactions: We study the impact of the leading non-renormalizable terms in the effective\nfield theory that describes general extensions of the Standard Model with\nvector-like quarks. Dropping the usual assumption of renormalizability has\nseveral phenomenological consequences for the production and decay of the heavy\nquarks and also for Higgs physics. The most dramatic effects, including those\nassociated with a long lifetime, occur for vector-like quarks with non-standard\nquantum numbers.", "category": "hep-ph" }, { "text": "Sfermion masses in the supersymmetric economical 3-3-1 model: Sfermion masses and eigenstates in the supersymmetric economical 3-3-1 model\nare studied. By lepton number conservation, the exotic squarks and\nsuperpartners of ordinary quarks are decoupled. Due to the fact that in the\n3-3-1 models, one generation of quarks behaves differently from other two, by\nR-parity conservation, the mass mixing matrix of the squarks in this model are\nsmaller than that in the Minimal Supersymmetric Standard Model (MSSM). Assuming\nsubstantial mixing in pairs of highest flavours, we are able to get mass\nspectrum and eigenstates of all the sfermions. In the effective approximation,\nthe slepton mass splittings in the first two generations, are consistent with\nthose in the MSSM, namely: $ m^2_{\\tilde{l}_L} - m^2_{\\tilde{\\nu}_{l L}} =\nm_W^2 \\cos 2\\ga$ $(l=e, \\mu)$. In addition, within the above effective limit,\nthere exists degeneracy among sneutrinos in each multiplet:\n$m^2_{\\tilde{\\nu}_{l L}} = m^2_{\\tilde{\\nu}_{l R}}$. In contradiction to the\nMSSM, the squark mass splittings are different for each generation and not to\nbe $ m_W^2 \\cos 2\\ga$.", "category": "hep-ph" }, { "text": "Weak interaction corrections to hadronic top quark pair production:\n contributions from quark-gluon and $b \\bar b$ induced reactions: As an addendum to our previous evaluation of the weak-interaction corrections\nto hadronic top-quark pair production we determine the leading weak-interaction\ncontributions due to the subprocesses $b {\\bar b} \\to t {\\bar t}$ and $g q\n({\\bar q}) \\to t {\\bar t} q ({\\bar q})$. For several distributions in $t {\\bar\nt}$ production at the LHC we find that these contributions are non-negligible\nas compared to the weak corrections from the other partonic subprocesses.", "category": "hep-ph" }, { "text": "Low Energy Theorems of Hidden Local Symmetries: We prove to all orders of the loop expansion the low energy theorems of\nhidden local symmetries in four-dimensional nonlinear sigma models based on the\ncoset space $G/H$, with $G$ and $H$ being arbitrary compact groups. Although\nthe models are non-renormalizable, the proof is done in an analogous manner to\nthe renormalization proof of gauge theories and two-dimensional nonlinear sigma\nmodels by restricting ourselves to the operators with two derivatives (counting\na hidden gauge boson field as one derivative), i.e., with dimension 2, which\nare the only operators relevant to the low energy limit. Through loop-wise\nmathematical induction based on the Ward-Takahashi identity for the BRS\nsymmetry, we solve renormalization equation for the effective action up to\ndimension-2 terms plus terms with the relevant BRS sources. We then show that\nall the quantum corrections to the dimension-2 operators, including the finite\nparts as well as the divergent ones, can be entirely absorbed into a\nre-definition (renormalization) of the parameters and the fields in the\ndimension-2 part of the tree-level Lagrangian.", "category": "hep-ph" }, { "text": "Neutrino quantum states and spin light in matter: On the basis of the exact solutions of the modified Dirac equation for a\nmassive neutrino moving in matter we develop the quantum theory of the spin\nlight of neutrino ($SL\\nu$). The expression for the emitted photon energy is\nderived as a function of the density of matter for different matter\ncompositions. The dependence of the photon energy on the helicities of the\ninitial and final neutrino states is shown explicitly. The rate and radiation\npower of the $SL\\nu$ in matter are obtained with the emitted photon linear and\ncircular polarizations being accounted for. The developed quantum approach to\nthe $SL\\nu$ in matter (which is similar to the Furry representation of\nelectrodynamics) can be used in the studies of other processes with neutrinos\nin the presence of matter", "category": "hep-ph" }, { "text": "Implication of the B -> rho rho data on the B -> pi pi puzzle: We point out that the B -> rho rho data have seriously constrained the\npossibility of resolving the B -> pi pi puzzle from the large observed B^0 ->\npi^0 pi^0 branching ratio in the available theoretical approaches. The\nnext-to-leading-order (NLO) contributions from the vertex corrections, the\nquark loops, and the magnetic penguin evaluated in the perturbative QCD (PQCD)\napproach have saturated the experimental upper bound of the B^0 -> rho^0 rho^0\nbranching ratio, and do not help. The NLO PQCD predictions for the B^0 ->\nrho^\\mp rho^\\pm and B^\\pm -> rho^\\pm rho^0 branching ratios are consistent with\nthe data. The inclusion of the NLO jet function from the soft-collinear\neffective theory into the QCD-improved factorization approach, though enhancing\nthe B^0 -> pi^0 pi^0 branching ratio sufficiently, overshoots the bound of the\nB^0 -> rho^0 rho^0 branching ratio, and deteriorates the predictions for the\nB^\\pm -> pi^0 K^\\pm and B^0 -> pi^\\mp K^\\pm direct CP asymmetries.", "category": "hep-ph" }, { "text": "Self-consistent statistical error analysis of $\u03c0\u03c0$ scattering: We analyze the conditions under which a statistical error analysis can be\ncarried out in the case of $\\pi\\pi$ scattering, namely the normality of\nresiduals in the conventional $\\chi^2$-fit method. Here we check that the\ncurrent and benchmarking analyses only present very small violations of the\nnormality requirements. In particular, we show how it is possible to amend\nslightly the selection of the experimental data, and improve the normality of\nresiduals.\n As an example, we discuss the $0^{++}$ channel and the implications for the\n$f_0(500)$ and $f_0(980)$ resonances, obtaining that the new selection of data\nprovides very similar and compatible results. In addition, the effect on the\n$f_0(500)$ and $f_0(980)$ resonance pole parameters is almost negligible, which\nreinforces the central results and the uncertainty analysis performed in these\nbenchmarking determinations.", "category": "hep-ph" }, { "text": "Quantum corrections to leptogenesis from the gradient expansion: Using the closed-time-path formalism we quantify gradient corrections to the\nkinetic equations for leptogenesis, that are neglected in the standard\nBoltzmann approach. In particular we show that an additional CP-violating\nsource term arises, which is non-zero even when all species are in local\nthermal equilibrium. In the early universe it is proportional to the expansion\nrate and would vanish for static equilibrium configurations, in accordance with\nthe Sakharov conditions. We find that for thermal leptogenesis in a standard\ncosmological background the additional source term is small. However, it can\nbecome the dominant source in the limit of ultra-strong washout.", "category": "hep-ph" }, { "text": "Matter-gravity interaction in a multiply warped braneworld,: The role of a bulk graviton in predicting the signature of extra dimensions\nthrough collider-based experiments is explored in the context of a multiply\nwarped spacetime. In particular it is shown that in a doubly warped braneworld\nmodel, the presence of the sixth dimension, results in enhanced concentration\nof graviton Kaluza Klein (KK) modes compared to that obtained in the usual\n5-dimensional Randall-Sundrum model. Also, the couplings of these massive\ngraviton KK modes with the matter fields on the visible brane turn out to be\nappreciably larger than that in the corresponding 5- dimensional model. The\nsignificance of these results are discussed in the context of KK graviton\nsearch at the Large Hadron Collider (LHC).", "category": "hep-ph" }, { "text": "Transversity Distribution Functions in the Valon Model: By using the valon model, we calculate the Transverse Momentum Distribution\nfunctions, TMDs, inside the Nucleon. TMDs indicate the probability to find\npartons with spin aligned (anti- aligned) to the transversely polarized\nnucleon. The results are in good agreements with all available experimental\ndata and also global fits.", "category": "hep-ph" }, { "text": "Do W_L and H form a p-wave bound state?: We examine the possibility of bound state formation in the W_L H --> W_L H\nchannel. The dynamical calculation using the N/D method indicates that when the\ninteractions among the Goldstone and Higgs bosons become sufficiently strong, a\np-wave state [I^G(J^P)=1^-(1^+)] may emerge.", "category": "hep-ph" }, { "text": "Gribov's Equation for the Green Function of Light Quarks: Gribov's scenario of supercritical charges in QCD is investigated. We perform\na numerical study of the corresponding equation for the Green function of light\nquarks. This is done in an approximation which neglects all pion contributions.\nDifferent types of solutions in the Euclidean region are discussed and the mass\nfunction of the quark is calculated. The solutions of the equation are shown to\nhave a qualitatively different behaviour if the strong coupling constant\nalpha_s exceeds a critical value alpha_c = 0.43 in the infrared region. Chiral\nsymmetry breaking is found to occur at supercritical coupling. The analytic\nstructure of the solutions is investigated. Earlier results obtained by Gribov\nare confirmed and extended.", "category": "hep-ph" }, { "text": "Supersymmetric D-term Inflation, Reheating and Affleck-Dine Baryogenesis: The phenomenology of supersymmetric models of inflation, where the\ninflationary vacuum energy is dominated by D-terms of a U(1), is investigated.\nParticular attention is paid to the questions of how to arrange for sufficient\ne-folds of inflation to occur, what kind of thermal history is expected after\nthe end of inflation, and how to implement successful baryogenesis. Such models\nare argued to require a more restrictive symmetry structure than previously\nthought. In particular, it is non-trivial that the decays of the fields driving\nD-inflation can reheat the universe in such a way as to avoid the strong\ngravitino production constraints. We also show how the initial conditions for\nAffleck-Dine baryogenesis can arise in these models and that the simplest flat\ndirections along which baryon number is generated can often be ruled out by the\nconstraints coming from decoherence of the condensate in a hot environment. At\nthe end, we find that successful reheating and baryogenesis can take place in a\nlarge subset of D-inflationary models.", "category": "hep-ph" }, { "text": "Covariant Description of Flavor Conversion in the LHC Era: A simple covariant formalism to describe flavor and CP violation in the\nleft-handed quark sector in a model independent way is provided. The\nintroduction of a covariant basis, which makes the standard model approximate\nsymmetry structure manifest, leads to a physical and transparent picture of\nflavor conversion processes. Our method is particularly useful to derive robust\nbounds on models with arbitrary mechanisms of alignment. Known constraints on\nflavor violation in the K and D systems are reproduced in a straightforward\nmanner. Assumptions-free limits, based on top flavor violation at the LHC, are\nthen obtained. In the absence of signal, with 100 fb^{-1} of data, the LHC will\nexclude weakly coupled (strongly coupled) new physics up to a scale of 0.6 TeV\n(7.6 TeV), while at present no general constraint can be set related to Delta\nt=1 processes. LHC data will constrain Delta F=2 contributions via same-sign\ntops signal, with a model independent exclusion region of 0.08 TeV (1.0 TeV).\nHowever, in this case, stronger bounds are found from the study of CP violation\nin D-bar D mixing with a scale of 0.57 TeV (7.2 TeV). In addition, we apply our\nanalysis to models of supersymmetry and warped extra dimension. The minimal\nflavor violation framework is also discussed, where the formalism allows to\ndistinguish between the linear and generic non-linear limits within this class\nof models.", "category": "hep-ph" }, { "text": "Advantages of exclusive \u03b3\u03b3production to probe high mass\n systems: We recall that the exclusive production of high mass objects via \\gamma\\gamma\nfusion at the LHC is not strongly suppressed in comparison with inclusive\n\\gamma\\gamma fusion. Therefore it may be promising to study new objects\nproduced by the \\gamma\\gamma subprocess in experiments with exclusive\nkinematics. We list the main advantages of exclusive experiments. We discuss\nthe special advantage of observing $\\gamma\\gamma \\to X \\to \\gamma Z$ exclusive\nevents.", "category": "hep-ph" }, { "text": "Top quark anomalous tensor couplings in the two-Higgs-doublet models: We compute the one loop right and left anomalous tensor couplings ($g_R$ and\n$g_L$, respectively) for the top quark, in the aligned two-Higgs-doublet model.\nThey are the magnetic-like couplings in the most general parameterization of\nthe $tbW$ vertex. We find that the aligned two-Higgs doublet model, that\nincludes as particular cases some of the most studied extensions of the Higgs\nsector, introduces new electroweak contributions and provides theoretical\npredictions that are very sensitive to both new scalar masses and the neutral\nscalar mixing angle. For a large area in the parameters space we obtain\nsignificant deviations in both the real and the imaginary parts of the\ncouplings $g_R$ and $g_L$, compared to the predictions given by the electroweak\nsector of the Standard Model. The most important ones are those involving the\nimaginary part of the left coupling $g_{L}$ and the real part of the right\ncoupling $g_R$. The real part of $g_L$ and the imaginary part of $g_R$ also\nshow an important sensitivity to new physics scenarios. The model can also\naccount for new CP violation effects via the introduction of complex alignment\nparameters that have important consequences on the values for the imaginary\nparts of the couplings. The top anomalous tensor couplings will be measured at\nthe LHC and at future colliders providing a complementary insight on new\nphysics, independent from the bounds in top decays coming from B physics and $b\n\\rightarrow s \\gamma$.", "category": "hep-ph" }, { "text": "Neutralino Dark Matter with Inert Higgsinos and Singlinos: We discuss neutralino dark matter arising from supersymmetric models with\nextra inert Higgsinos and singlinos, where inert means that their scalar\npartners do not get vacuum expectation values. As an example, we consider the\nextended neutralino sector of the E$_6$SSM, which predicts three families of\nHiggs doublet pairs, plus three singlets, plus a $Z'$, together with their\nfermionic superpartners. We show that the two families of inert doublet\nHiggsinos and singlinos predicted by this model provide an almost decoupled\nneutralino sector with a naturally light LSP which can account for the cold\ndark matter relic abundance independently of the rest of the model, providing\nthat the ratio of the two usual Higgs doublets satisfies tan beta < 2.", "category": "hep-ph" }, { "text": "Lambda Oscillations and the Conservation Laws: Lowe, Bassalleck, Burkhardt, Rusek, Stephenson, and Goldman assert, under the\nassumption of decays at fixed space-time points, that Kaon induced Lambda\noscillations disappear. We find, under the same assumption, that energy\nconservation and momentum conservation also disappear. Ordinary particles can\nexhibit quantum oscillations.", "category": "hep-ph" }, { "text": "Vacuum energy and the cosmological constant: The accelerating expansion of the Universe points to a small positive value\nfor the cosmological constant or vacuum energy density. We discuss recent ideas\nthat the cosmological constant plus LHC results might hint at critical\nphenomena near the Planck scale.", "category": "hep-ph" }, { "text": "A description of the ratio between electric and magnetic proton form\n factors by using space-like, time-like data and dispersion relations: We use the available information on the ratio between the electric and\nmagnetic proton form factors coming from recently published space-like data and\nfrom the few available time-like data. We apply a dispersive procedure on these\ndata to evaluate the behaviour of this ratio, as a complex function, for all\nvalues of q^2.", "category": "hep-ph" }, { "text": "Nonuniversality of indirect CP asymmetries in $D \\to \u03c0\u03c0, KK$ decays: We point out that, if the direct CP asymmetries in the $D \\to \\pi^+ \\pi^-$\nand $D \\to K^+ K^-$ decays are unequal, the indirect CP asymmetries as measured\nin these modes are necessarily unequal. This nonuniversality of indirect CP\nasymmetries can be significant with the right amount of new physics\ncontributions, a scenario that may be fine-tuned, but is still viable. A\nmodel-independent fit to the current data allows different indirect CP\nasymmetries in the above two decays. This could even be contributing to the\napparent tension between the difference CP asymmetries $\\Delta A_{\\rm CP}$\nmeasured through the pion-tagged and muon-tagged data samples at the LHCb. This\nalso implies that the measurements of $A_\\Gamma$ and $y_{\\rm CP}$ in the $\\pi^+\n\\pi^-$ and $K^+ K^-$ decay modes can be different, and averaging over these two\nmodes should be avoided. In any case, the complete analysis of CP violation\nmeasurements in the $D$ meson sector needs to take into account the possibility\nof different indirect CP asymmetries in the $\\pi^+\\pi^-$ and $K^+ K^-$\nchannels.", "category": "hep-ph" }, { "text": "Inclusive electromagnetic decays of the heavy quarkonium at next to\n leading log accuracy: We show that perturbation theory may give reasonable numbers for the decays\nof the bottomonium and charmonium ground states to $e^+e^-$ and to\n$\\gamma\\gamma$. To reach this conclusion it is important to perform the\nresummation of logs. In particular, we obtain the value $\\Gamma(\\eta_b (1S) \\to\n\\gamma\\gamma)=0.35 \\pm 0.1 ({\\rm th.}) \\pm 0.05 (\\lQ)$ KeV.", "category": "hep-ph" }, { "text": "Inverse Problem of Cosmic-Ray Electron/Positron from Dark Matter: We discuss the possibility of solving the inverse problem of the cosmic-ray\nelectron/positron from decaying/annihilating dark matter, and show simple\nanalytic formulae to reconstruct the source spectrum of the electron/positron\nfrom the observed flux. We also illustrate our approach by applying the\nobtained formula to the just released Fermi data as well as the new HESS data.", "category": "hep-ph" }, { "text": "Higgs Physics at the LHC: Some Theory Aspects: In these lecture notes we review some prospect for the upcoming LHC\nexperiments in view of the exploration of the Standard Model (SM) or its\nminimal Supersymmetric extension (MSSM). We focus on some theoretical aspects\nconcerning the Higgs sector of the two models. We give results for the\nprecision observables M_W and m_t and their impact on the indirect\ndetermination of the Higgs sector. We furthermore review some prospects for the\ndirect measurements in the SM and MSSM Higgs sector.", "category": "hep-ph" }, { "text": "Hadronic Higgs boson decay at order $\u03b1_s^4$ and $\u03b1_s^5$: We compute corrections to the decay of the Standard Model Higgs boson to\nhadrons, to the fourth order in the strong coupling constant $\\alpha_s$. We use\nan effective theory in which the Higgs boson couples directly to bottom quarks\nand to gluons, via top quark--mediated effective couplings. Numerically, our\nresults are of a comparable size to the previously-known \"massless\"\ncontributions and complete the order $\\alpha_s^4$ corrections to the hadronic\ndecay of the Higgs boson. In these proceedings we also provide an independent\ncross check of the gluonic Higgs boson decay at order $\\alpha_s^5$.", "category": "hep-ph" }, { "text": "Hadronic Light-by-light Scattering Effect on Muon g-2: The hadronic light-by-light scattering contribution to muon $g-2$ is examined\nusing low energy effective theories of QCD, the Nambu-Jona-Lasinio model and\nhidden local chiral symmetry, as guides. Our result is $- 36 \\times 10^{-11}$\nwith an uncertainty of $\\pm 16 \\times 10^{-11}$, which includes our best\nestimate of model dependence. This is within the expected measurement\nuncertainty of $40\\times 10^{-11}$ in the forthcoming experiment at Brookhaven\nNational Laboratory. Our result removes one of the main theoretical obstacles\nin verifying the existence of the weak contribution to the muon $g-2$.", "category": "hep-ph" }, { "text": "CP violation in bilinear R-parity violation and its consequences for the\n early universe: Supersymmetric models with bilinear R-parity violation (BRpV) provide a\nframework for neutrino masses and mixing angles to explain neutrino oscillation\ndata. We consider CP violation within the new physical phases in BRpV and\ndiscuss their effect on the generation of neutrino masses and the decays of the\nlightest supersymmetric particle (LSP), being a light neutralino with mass\n$\\sim 100$ GeV, at next-to-leading order. The decays affect the lepton and via\nsphaleron transitions the baryon asymmetry in the early universe. For a rather\nlight LSP, asymmetries generated before the electroweak phase transition via\ne.g. the Affleck-Dine mechanism are reduced up to two orders of magnitude, but\nare still present. On the other hand, the decays of a light LSP themselves can\naccount for the generation of a lepton and baryon asymmetry, the latter in\naccordance to the observation in our universe, since the smallness of the BRpV\nparameters allows for an out-of-equilibrium decay and sufficiently large CP\nviolation is possible consistent with experimental bounds from the\nnon-observation of electric dipole-moments.", "category": "hep-ph" }, { "text": "Vector gauge boson radiation from compact binary systems in a gauged\n $L_\u03bc-L_\u03c4$ scenario: The orbital period of a compact binary system decays mainly due to quadrupole\ngravitational radiation, which agrees with the observation to within one\npercent. Other types of radiation such as ultralight scalar or pseudoscalar\nradiation, massive vector boson radiation also contribute to the decay of\norbital period as long as the mass of the emitted particle is less than the\norbital frequency of the compact binary system. We obtain an expression of the\nenergy loss due to the radiation of massive vector field from the neutron\nstar-neutron star and neutron star-white dwarf binaries. Due to large chemical\npotential of the degenerate electrons, neutron stars have large muon charge. We\nderive the energy loss due to $U(1)_{L_\\mu-L_\\tau}$ gauge boson radiation from\nthe binaries. For the radiation of vector boson, the mass is restricted by\n$M_{Z^\\prime}<\\Omega \\simeq10^{-19}eV$ are the orbital frequencies of the\ncompact star binaries. Using the formula of orbital period decay, we obtain\nconstraints on the coupling constant of the gauge boson in the gauged\n$L_\\mu-L_\\tau$ theory for the four compact binary systems. For vector gauge\nboson muon coupling we find that for $M_{Z^\\prime}<10^{-19}eV$, constraints on\nthe coupling constant is $g<\\mathcal{O}(10^{-20})$. We also obtain the\nexclusion plots of the massive vector proca field and the gauge field which can\ncouple to muons.", "category": "hep-ph" }, { "text": "Relic Abundance of Neutralinos in Heterotic String Theory: Weak Coupling\n vs. Strong Coupling: The relic abundance of stable neutralinos is investigated in $E_8 \\times\nE_8'$ heterotic string theory when supersymmetry is spontaneously broken by\nhidden-sector gaugino condensates. In the weak coupling regime, very large\nscalar masses (compared to gaugino masses) are shown to lead to a too large\nrelic abundance of the neutralinos, incompatible with cosmological observations\nin most of parameter space. The problem does not arise in the strong coupling\nregime (heterotic M-theory) because there scalar and gaugino masses are\ngenerically of the same order of magnitude.", "category": "hep-ph" }, { "text": "The Hunting of the MR Model: We consider experimental signatures of the standard model's minimal\nsupersymmetric extension with a continuous $U(1)_R$ symmetry (MR model). We\nfocus on the ability of existing and planned electron-positron colliders to\nprobe this model and to distinguish it from both the standard model and the\nstandard model's minimal supersymmetric extension with a discrete $R$-parity.", "category": "hep-ph" }, { "text": "Heavy neutral 2HDM Higgs Boson Pair Production at CLIC Energies: In this work, the neutral Higgs boson pair production is analyzed at Compact\nLinear Collider (CLIC) to be operating at center of mass energies\n$\\sqrt{s}$=1400 GeV (stage 2) and $\\sqrt{s}$=3000 GeV (stage 3). The Higgs\nbosons to be searched for are neutral CP-even (H) and CP-odd (A) within the\nframework of two Higgs doublet model (2HDM) in the mass range 300 < mH/A < 1000\nGeV. All types of the CP-conserving model are studied and the signal\nobservability is evaluated taking into account the main SM background processes\nlike ZZ, tt and the SM-like Higgs boson associated production (hZ). Results are\npresented for a set of model parameters and Higgs boson masses in terms of\nsignal distributions over the background as well as the integrated luminosity\nneeded for 5{\\sigma} discovery. It is shown that the heavy mass region is well\nobservable at CLIC in types 3 (flipped) and 4 (lepton-specific) in the regions\nnot excluded by LHC so far, while in type 1 the signal observation is\nchallenging due to the large jet multiplicity in the tt final state.", "category": "hep-ph" }, { "text": "CP violation and limits on New Physics including recent $B_s$\n measurements: We analyse present constraints on the SM parameter space and derive, in a\nmodel independent way, various bounds on New Physics contributions to\n$B_d^0$--$\\bar B_d^0$ and $B_s^0$--$\\bar B_s^0$ mixings. Our analyses include\ninformation on a large set of asymmetries, leading to the measurement of the\nCKM phases $\\gamma$ and $\\bar\\beta$, as well as recent data from D0 and CDF\nrelated to the $B_s^0$--$\\bar B_s^0$ system such as the measurement of $\\Delta\nM_{B_s}$, $A_{SL}$ and $\\Delta\\Gamma_{s}^{CP}$. We examine in detail several\nobservables such as the asymmetries $A_{sl}^d$, $A_{SL}$, the width differences\n$\\Delta\\Gamma_{d}$ and $\\Delta\\Gamma_{s}^{CP}$ and discuss the r\\^ole they play\nin establishing the limits on New Physics. The present data clearly favour the\nSM, with the New Physics favoured region placed around the SM solution. A New\nPhysics solution significantly different from the SM is still allowed, albeit\nquite disfavoured (2.6% probability). We analyse the presently available\nindirect knowledge on the phase $\\bar\\chi$ entering in $B_s^0$--$\\bar B_s^0$\nmixing and study the impact of a future measurement of $\\bar\\chi$ to be\nachieved at LHC, through the measurement of the time-dependent CP asymmetry in\n$B_s\\to J/\\Psi \\Phi$ decays.", "category": "hep-ph" }, { "text": "The Fundamental Constants in Physics: We discuss the fundamental constants of physics in the Standard Model and\npossible changes of these constants on the cosmological time scale. The Grand\nUnification of the strong, electromagnetic and weak interactions implies\nrelations between the time variation of the finestructure constant and of the\nQCD scale. An experiment in quantum optics at the MPQ in Munich, which was\ndesigned to look for a time variation of the QCD scale, is discussed.", "category": "hep-ph" }, { "text": "Asymmetric Dark Matter via Spontaneous Co-Genesis: We investigate, in the context of asymmetric dark matter (DM), a new\nmechanism of spontaneous co-genesis of linked DM and baryon asymmetries,\nexplaining the observed relation between the baryon and DM densities,\nOmega_DM/Omega_B ~ 5. The co-genesis mechanism requires a light scalar field,\nphi, with mass below 5 eV which couples derivatively to DM, much like a `dark\naxion'. The field phi can itself provide a final state into which the residual\nsymmetric DM component can annihilate away.", "category": "hep-ph" }, { "text": "Connection between diphoton and triboson channels in new physics\n searches: Diphoton channel provides a clean signature in searches for new physics. In\nthis paper, we discuss a connection between the diphoton channel\n($\\gamma\\gamma$) and triboson channels ($Z\\gamma\\gamma$, $ZZ\\gamma$,\n$WW\\gamma$) imposed by the $SU(2)_{L}\\times U(1)_{Y}$ symmetry of the Standard\nModel (SM) in certain classes of models. To illustrate this idea we choose a\nsimple model that has all these channels. In this model, the same physics can\ngive rise to $\\gamma+$MET instead of $\\gamma\\gamma$ and 2 bosons plus missing\nenergy instead of 3-boson channels. We analyze existing constraints and\nprevious searches and show that channels $WW\\gamma$ and especially\n$Z\\gamma+$MET have a potential to discover new physics at the LHC.", "category": "hep-ph" }, { "text": "Universality of Nonperturbative Effects in Event Shapes: Nonperturbative effects in event shape distributions can be characterized by\nshape functions derived in the eikonal approximation or, equivalently, from\nsoft-collinear effective theory. The use of energy flow operators and the boost\ninvariance of the Wilson lines of soft gluons in the shape functions leads to a\nproof of universality for power corrections to the mean values of event shapes,\nwithout invoking the single gluon approximation.", "category": "hep-ph" }, { "text": "Cornering pseudoscalar-mediated dark matter with the LHC and cosmology: Models in which dark matter particles communicate with the visible sector\nthrough a pseudoscalar mediator are well-motivated both from a theoretical and\nfrom a phenomenological standpoint. With direct detection bounds being\ntypically subleading in such scenarios, the main constraints stem either from\ncollider searches for dark matter, or from indirect detection experiments.\nHowever, LHC searches for the mediator particles themselves can not only\ncompete with -- or even supersede -- the reach of direct collider dark matter\nprobes, but they can also test scenarios in which traditional monojet searches\nbecome irrelevant, especially when the mediator cannot decay on-shell into dark\nmatter particles or its decay is suppressed. In this work we perform a detailed\nanalysis of a pseudoscalar-mediated dark matter simplified model, taking into\naccount a large set of collider constraints and concentrating on the parameter\nspace regions favoured by cosmological and astrophysical data. We find that\nmediator masses above 100-200~GeV are essentially excluded by LHC searches in\nthe case of large couplings to the top quark, while forthcoming collider and\nastrophysical measurements will further constrain the available parameter\nspace.", "category": "hep-ph" }, { "text": "Exclusive meson pair production in gamma* gamma scattering at small\n momentum transfer: We study the exclusive production of pi pi and rho pi in hard gamma* gamma\nscattering in the forward kinematical region where the virtuality of one photon\nprovides us with a hard scale in the process. The newly introduced concept of\nTransition Distribution Amplitudes (TDA) is used to perform a QCD calculation\nof these reactions thanks to two simple models for TDAs. Cross sections for rho\npi and pi pi production are evaluated and compared to the possible background\nfrom the Bremsstrahlung process. This picture may be tested at intense\nelectron-positron colliders such as CLEO and B factories. The cross section e\ngamma -> e' pi0 pi0 is finally shown to provide a possible determination of the\npi0 axial form factor, FA, at small t, which seems not to be measurable\nelsewhere.", "category": "hep-ph" }, { "text": "CP violation in the semileptonic top decay in two-Higgs doublet model: CP violation in semileptonic top-quark decay is investigated by exactly using\none charged- and three neutral-Higgs bosons obtained by solving the Higgs mass\nmatrix in two-Higgs doublet model. The CP-violating up-down asymmetry of\nleptons from $W$ boson decays is shown to be $1 \\times 10^{-4} - 4 \\times\n10^{-3}$ for the region of ${\\rm tan} \\beta \\ll 1$, where ${\\rm tan} \\beta $ is\nthe ratio of vacuum expectation values for the two neutral Higgs bosons.", "category": "hep-ph" }, { "text": "Coherent photoproduction of low-$p_{T}$ charmonium in peripheral heavy\n ion collisions within the color dipole model: We calculate the centrality dependence for coherent photoproduction of very\nlow-$p_{T}$ $J/\\psi$ at Relativistic Heavy Ion Collider (RHIC) and Large Hadron\nCollider (LHC) energies within the impact parameter dependent saturated color\ndipole model. By using the large equivalent photon fluxes, we present the\ndifferential cross section of very low-$p_{T}$ $J/\\psi$ produced by coherent\nphotonuclear in peripheral heavy-ion collisions. The numerical results\ndemonstrate that our calculation are agree with $J/\\psi$ data in peripheral\nheavy ion collisions at Relativistic Heavy Ion Collider (RHIC) energies.", "category": "hep-ph" }, { "text": "Magnetic Inelastic Dark Matter: Iodine is distinguished from other elements used in dark matter direct\ndetection experiments both by its large mass as well as its large magnetic\nmoment. Inelastic dark matter utilizes the large mass of iodine to allay\ntensions between the DAMA annual modulation signature and the null results from\nother experiments. We explore models of inelastic dark matter that also take\nadvantage of the second distinct property of iodine, namely its large magnetic\nmoment. In such models the couplings are augmented by magnetic, rather than\nmerely electric, interactions. These models provide simple examples where the\nDAMA signal is compatible with all existing limits. We consider dipole moments\nfor the WIMP, through conventional magnetism as well as \"dark\" magnetism,\nincluding both magnetic-magnetic and magnetic-electric scattering. We find\nXENON100 and CRESST should generically see a signal, although suppressed\ncompared with electric inelastic dark matter models, while KIMS should see a\nmodulated signal comparable to or larger than that of DAMA. In a large portion\nof parameter space, de-excitation occurs promptly, producing a ~ 100 keV photon\ninside large xenon experiments alongside the nuclear recoil. This effect could\nbe searched for, but if not properly considered may cause nuclear recoil events\nto fail standard cuts.", "category": "hep-ph" }, { "text": "From R_AA via correlations to jets - the long road to tomography: The main motivation to investigate hard probes in heavy ion collisions is to\ndo tomography, i.e. to infer medium properties from the in-medium modification\nof hard processes. Yet while the suppression of high P_T hadrons has been\nmeasured for some time, solid tomographic information is slow to emerge. This\ncan be traced back to theoretical uncertainties and ambiguities in modelling\nboth medium evolution and parton-medium interaction. Ways to overcome these\ndifficulties are to constrain models better and to focus on more differential\nobservables. Correlations of high P_T hadrons offer non-trivial information\nbeyond what can be deduced from single hadron suppression. They reflect not\nonly the hard reaction being modified by the medium, but also the back reaction\nof the medium to the hard probe. Models for hard back-to-back correlations are\nnow very well constrained by a wealth of data and allow insights into the\nnature of the parton-medium interaction as well as first true tomographic\nresults. Models of full in-medium jet evolution are being actively developed,\nbut have yet to make substantial contact with data. Progress is slower in the\nunderstanding of low P_T correlations, the ridge and the cone, although a\nqualitative understanding of the nature of the physics behind these\ncorrelations starts to emerge.", "category": "hep-ph" }, { "text": "Bayesian Selection of sign(mu) within mSUGRA in Global Fits Including\n WMAP5 Results: We study the properties of the constrained minimal supersymmetric standard\nmodel (mSUGRA) by performing fits to updated indirect data, including the relic\ndensity of dark matter inferred from WMAP5. In order to find the extent to\nwhich mu < 0 is disfavoured compared to mu > 0, we compare the Bayesian\nevidence values for these models, which we obtain straightforwardly and with\ngood precision from the recently developed multi-modal nested sampling\n('MultiNest') technique. We find weak to moderate evidence for the mu > 0\nbranch of mSUGRA over mu < 0 and estimate the ratio of probabilities to be P(mu\n> 0)/P(mu < 0) = 6-61 depending on the prior measure and range used. There is\nthus positive (but not overwhelming) evidence that mu > 0 in mSUGRA. The\nMultiNest technique also delivers probability distributions of parameters and\nother relevant quantities such as superpartner masses. We explore the\ndependence of our results on the choice of the prior measure used. We also use\nthe Bayesian evidence to quantify the consistency between the mSUGRA parameter\ninferences coming from the constraints that have the largest effects: (g-2)_mu,\nBR(b -> s gamma) and cold dark matter (DM) relic density Omega_{DM}h^2.", "category": "hep-ph" }, { "text": "(Light) Stop Signs: Stop squarks with a mass just above the top's and which decay to a nearly\nmassless LSP are difficult to probe because of the large SM di-top background.\nHere we discuss search strategies which could be used to set more stringent\nbounds in this difficult region. In particular, we note that both the rapidity\ndifference Delta y(t,tbar) and spin correlations (inferred from, for example,\nDelta phi(l+,l-)) are sensitive to the presence of stops. We emphasize that\nsystematic uncertainties in top quark production can confound analyses looking\nfor stops, making theoretical and experimental progress on the understanding of\nStandard Model top production at high precision a very important task. We\nestimate that spin correlation alone, which is relatively robust against such\nsystematic uncertainties, can exclude a 200 GeV stop at 95% confidence with 20\nfb^-1 at the 8 TeV LHC.", "category": "hep-ph" }, { "text": "Corrections to the ${\\bf SU(3)\\times SU(3)}$ Gell-Mann-Oakes-Renner\n relation and chiral couplings $L^r_8$ and $H^r_2$: Next to leading order corrections to the $SU(3) \\times SU(3)$\nGell-Mann-Oakes-Renner relation (GMOR) are obtained using weighted QCD Finite\nEnergy Sum Rules (FESR) involving the pseudoscalar current correlator. Two\ntypes of integration kernels in the FESR are used to suppress the contribution\nof the kaon radial excitations to the hadronic spectral function, one with\nlocal and the other with global constraints. The result for the pseudoscalar\ncurrent correlator at zero momentum is $\\psi_5(0) = (2.8 \\pm 0.3) \\times\n10^{-3} GeV^{4}$, leading to the chiral corrections to GMOR: $\\delta_K = (55\n\\pm 5)%$. The resulting uncertainties are mostly due to variations in the upper\nlimit of integration in the FESR, within the stability regions, and to a much\nlesser extent due to the uncertainties in the strong coupling and the strange\nquark mass. Higher order quark mass corrections, vacuum condensates, and the\nhadronic resonance sector play a negligible role in this determination. These\nresults confirm an independent determination from chiral perturbation theory\ngiving also very large corrections, i.e. roughly an order of magnitude larger\nthan the corresponding corrections in chiral $SU(2) \\times SU(2)$. Combining\nthese results with our previous determination of the corrections to GMOR in\nchiral $SU(2) \\times SU(2)$, $\\delta_\\pi$, we are able to determine two low\nenergy constants of chiral perturbation theory, i.e. $L^r_8 = (1.0 \\pm 0.3)\n\\times 10^{-3}$, and $H^r_2 = - (4.7 \\pm 0.6) \\times 10^{-3}$, both at the\nscale of the $\\rho$-meson mass.", "category": "hep-ph" }, { "text": "Dark Matters in Gauged B-3L_i Model: We study a dark matter model with local B-3L_i symmetry that is known as\nanomaly free and requires a single right-handed neutrino. Here we have two dark\nmatter candidates; that is, fermionic or bosonic one. We focus on analyzing\neach of the case within the light mass region, which is required by the\nperturbative theory of the Higgs quartic coupling.", "category": "hep-ph" }, { "text": "Resolved Photon Processes: We review the present level of knowledge of the hadronic structure of the\nphoton, as revealed in interactions involving quarks and gluons ``in\" the\nphoton. The concept of photon structure functions is introduced in the\ndescription of deep--inelastic $e \\gamma$ scattering, and existing\nparametrizations of the parton densities in the photon are reviewed. We then\nturn to hard \\gamp\\ and \\gaga\\ collisions, where we treat the production of\njets, heavy quarks, hard (direct) photons, \\jpsi\\ mesons, and lepton pairs. We\nalso comment on issues that go beyond perturbation theory, including recent\nattempts at a comprehensive description of both hard and soft \\gamp\\ and \\gaga\\\ninteractions. We conclude with a list of open problems.", "category": "hep-ph" }, { "text": "Feynman rules for the rational part of the Electroweak 1-loop amplitudes: We present the complete set of Feynman rules producing the rational terms of\nkind R_2 needed to perform any 1-loop calculation in the Electroweak Standard\nModel. Our results are given both in the 't Hooft-Veltman and in the Four\nDimensional Helicity regularization schemes. We also verified, by using both\nthe 't Hooft-Feynman gauge and the Background Field Method, a huge set of Ward\nidentities -up to 4-points- for the complete rational part of the Electroweak\namplitudes. This provides a stringent check of our results and, as a\nby-product, an explicit test of the gauge invariance of the Four Dimensional\nHelicity regularization scheme in the complete Standard Model at 1-loop. The\nformulae presented in this paper provide the last missing piece for completely\nautomatizing, in the framework of the OPP method, the 1-loop calculations in\nthe SU(3) X SU(2) X U(1) Standard Model.", "category": "hep-ph" }, { "text": "The $\u03b8$-Vacua and the Leutwyler--Smilga Scaling Regime: The partition function of QCD is studied in the Leutwyler--Smilga scaling\nregime for an arbitrary number of quark flavors and masses including the\ncontributions from all winding numbers. For $N_f=2$ and degenerate quark\nmasses, the partition function becomes independent of the quark masses at\n$\\theta=\\pi$ and subsequently the scalar chiral condensate vanishes. There is a\ndiscontinuity at $\\theta=\\pi$ in the first derivative of the energy density\nwith respect to $\\theta$ corresponding to the first--order phase transition in\nwhich CP is spontaneously broken, known as Dashen's phenomena. These properties\nare found to be insensitive to both the pattern of chiral symmetry breaking and\nthe representation of the quark fields.", "category": "hep-ph" }, { "text": "Composite Dynamics in the Early Universe: We study the occurrence of a strong first-order electroweak phase transition\nin composite Higgs models. Minimal constructions realising this scenario are\nbased on the coset SO(6)/SO(5) which delivers an extended Higgs sector with an\nadditional scalar. In such models, a two-step phase transition can be obtained\nwith the scalar singlet acquiring a vacuum expectation value at intermediate\ntemperatures. A bonus of the Nambu-Goldstone boson nature of the scalar-sector\ndynamics is the presence of non-renormalisable Higgs interactions that can\ntrigger additional sources of CP violation needed to realise baryogenesis at\nthe electroweak scale. Another interesting aspect of this scenario is the\ngeneration of gravitational wave signatures that can be observed at future\nspace-based interferometers.", "category": "hep-ph" }, { "text": "Study of LHC Searches for a Lepton and Many Jets: Searches for new physics in high-multiplicity events with little or no\nmissing energy are an important component of the LHC program, complementary to\nanalyses that rely on missing energy. We consider the potential reach of\nsearches for events with a lepton and six or more jets, and show they can\nprovide increased sensitivity to many supersymmetric and exotic models that\nwould not be detected through standard missing-energy analyses. Among these are\nsupersymmetric models with gauge mediation, R-parity violation, and light\nhidden sectors. Moreover, ATLAS and CMS measurements suggest the primary\nbackground in this channel is from t-tbar, rather than W+jets or QCD, which\nreduces the complexity of background modeling necessary for such a search. We\nalso comment on related searches where the lepton is replaced with another\nvisible object, such as a Z boson.", "category": "hep-ph" }, { "text": "Distinguishing the Color Octet Axial-Vector-like Particle for Top Quark\n Asymmetry via Color Flow Method at the LHC: The excess in top quark forward-backward asymmetry has been a hot topic in\nrecent years. Although there are many proposals to explain it, most of them can\nnot fit the differential distributions well. The color octet axial-vector like\nparticle, with mass near the top quark pair threshold, is still a good\ndescription of the differential distributions. We study how to distinguish the\ncolor singlet and octet mediating particles in top quark pair production by\nadopting the color flow method. For the first time, we show that such a\nproposal for the froward-backward asymmetry can be cross-checked indirectly at\nthe LHC.", "category": "hep-ph" }, { "text": "Unusual condensates in quark and atomic systems: In these lectures we discuss condensates which are formed in quark matter\nwhen it is squeezed and in a gas of fermionic atoms when it is cooled. The\nbehavior of these two seemingly very different systems reveals striking\nsimilarities. In particular, in both systems the Bose-Einstein condensate to\nBardeen--Cooper-Schrieffer (BEC-BCS) crossover takes place.", "category": "hep-ph" }, { "text": "New extraction of CP violation in b-baryon decays: We study CP violation in b-baryon decays of $\\Xi_b^- \\to \\Xi^- D$ with $D =\nD^0, \\bar{D}^0$ and $D_i~(i=1,2)$. We find that these baryonic decay processes\nprovide an ideal opportunity to measure the weak phase due to the absence of\nthe relative strong phase. Explicitly, we relate $\\bar{\\rho}$ and $\\bar{\\eta}$\nthe CKM elements with the decay rate ratios of $R_i= \\Gamma(\\Xi_b^- \\to\n\\Xi^-D_{i} ) / \\Gamma( \\Xi_b^- \\to \\Xi^-D^0 )$ without the charge conjugate\nstates. As a complementary, we also examine the decay distributions of\n$\\Lambda_b \\to \\Lambda(\\to p \\pi^- ) D$. There are in total 32 decay\nobservables, which can be parameterized by 9 real parameters, allowing the\nexperiments to extract the angle $\\gamma\\equiv\n\\arg(-V_{ud}V_{ub}^*/V_{cd}V_{cb}^*)$ in the CKM unitarity triangle. In\naddition, the feasibilities of the experimental measurements are discussed. We\nfind that $\\bar{\\rho}$ and $\\bar{\\eta}$ can be extracted at LHCb Run3 from\n$\\Xi_b^- \\to \\Xi^- D$, and a full analysis of $\\Lambda_b \\to \\Lambda(\\to p\n\\pi^-)D$ is available at LHCb Run4.", "category": "hep-ph" }, { "text": "Unification of SUSY breaking and GUT breaking: We build explicit supersymmetric unification models where grand unified gauge\nsymmetry breaking and supersymmetry (SUSY) breaking are caused by the same\nsector. Besides, the SM-charged particles are also predicted by the symmetry\nbreaking sector, and they give the soft SUSY breaking terms through the\nso-called gauge mediation. We investigate the mass spectrums in an explicit\nmodel with SU(5) and additional gauge groups, and discuss its phenomenological\naspects. Especially, nonzero A-term and B-term are generated at one-loop level\naccording to the mediation via the vector superfields, so that the electro-weak\nsymmetry breaking and 125 GeV Higgs mass may be achieved by the large B-term\nand A-term even if the stop mass is around 1 TeV.", "category": "hep-ph" }, { "text": "An Updated Analysis of Inert Higgs Doublet Model in light of the Recent\n Results from LUX, PLANCK, AMS-02 and LHC: In light of the recent discovery by the ATLAS and CMS experiments at the\nLarge Hadron Collider (LHC) of a Higgs-like particle with a narrow mass range\nof 125-126 GeV, we perform an updated analysis on one of the popular scalar\ndark matter models, the Inert Higgs Doublet Model (IHDM). We take into account\nin our likelihood analysis of various experimental constraints, including\nrecent relic density measurement, dark matter direct and indirect detection\nconstraints as well as the latest collider constraints on the invisible decay\nwidth of the Higgs boson and monojet search at the LHC. It is shown that if the\ninvisible decay of the standard model Higgs boson is open, LHC as well as\ndirect detection experiments like LUX and XENON100 could put stringent limits\non the Higgs boson couplings to dark matter. We find that the most favoured\nparameter space for IHDM corresponds to dark matter with a mass less than 100\nGeV or so. In particular, the best-fit points are at the dark matter mass\naround 70 GeV where the invisible Higgs decay to dark matter is closed. Scalar\ndark matter in the higher mass range of 0.5-4 TeV is also explored in our\nstudy. Projected sensitivities for the future experiments of monojet at LHC-14,\nXENON1T and AMS-02 one year antiproton flux are shown to put further\nconstraints on the existing parameter space of IHDM.", "category": "hep-ph" }, { "text": "Electroweak Physics: Theoretical Overview: I give an overview of the theory status of predictions for single W and Z\nboson production at hadron colliders. I briefly report on work in progress for\nimprovements necessary to match the anticipated high precision of electroweak\nmeasurements, such as the W mass and width, at the Fermilab Tevatron p anti-p\nand the CERN LHC pp colliders.", "category": "hep-ph" }, { "text": "Generalized Friedberg-Lee model for CP violation in neutrino physics: We propose a phenomenological model of Dirac neutrino mass operator based on\nthe Fridberg-Lee (FL) neutrino mass model to include CP violation. By\nconsidering the most general set of complex coefficients, and imposing the\ncondition that the mass eigenvalues are real, we find a neutrino mass matrix\nwhich is non-hermitian, symmetric and magic. In particular, we find that the\nrequirement of obtaining real mass eigenvalues by transferring the residual\nphases to the mass eigenstates self-consistently, dictates the following\nrelationship between the imaginary part of the mass matrix elements $B$ and the\nparameters of the FL model:\n$B=\\pm\\sqrt{3/4(a-b_{r})^{2}\\sin^{2}2\\theta_{13}\\cos^{2}\\theta_{12}}$. We\nobtain inverted neutrino mass hierarchy, $m_{3}=0$. Making a correspondence\nbetween our model and the experimental data produces stringent conditions on\nthe parameters as follows:\n$35.06^{\\circ}\\lesssim\\theta_{12}\\lesssim36.27^{\\circ}$, $\\theta_{23}=\n45^{\\circ}$, $7.27^{\\circ}\\lesssim\\theta_{13}\\lesssim11.09^{\\circ}$, and\n$82.03^{\\circ}\\lesssim\\delta\\lesssim85.37^{\\circ}$. We get mildly broken\n$\\mu-\\tau$ symmetry, which reduces the resultant neutrino mixing pattern from\ntribimaximal (TBM) to trimaximal (TM). The CP violation as measured by the\nJarlskog parameter is restricted by $0.027\\lesssim J\\lesssim0.044$.", "category": "hep-ph" }, { "text": "Direct detection rate of heavy Higgsino-like and Wino-like dark matter: A large class of viable dark matter models contain a WIMP candidate that is a\ncomponent of a new electroweak multiplet whose mass $M$ is large compared to\nthe electroweak scale $m_W$. A generic amplitude-level cancellation in such\nmodels yields a severe suppression of the cross section for WIMP-nucleon\nscattering, making it important to assess the impact of formally subleading\neffects. The power correction of order $m_W/M$ to the heavy WIMP limit is\ncomputed for electroweak doublet (Higgsino-like) dark matter candidates, and a\nmodern model of nuclear modifications to the free nucleon cross section is\nevaluated. Corrections to the pure Higgsino limit are determined by a single\nparameter through first order in the heavy WIMP expansion. Current and\nprojected experimental bounds on this parameter are investigated. The direct\ndetection signal in the pure Higgsino limit remains below neutrino backgrounds\nfor WIMPs in the TeV mass range. Nuclear corrections are applied also to the\nheavy Wino case, completing the investigation of combined subleading effects\nfrom perturbative QCD, $1/M$ power corrections, and nuclear modifications.", "category": "hep-ph" }, { "text": "PHOTOS Interface in C++; Technical and Physics Documentation: For five years now, PHOTOS Monte Carlo for bremsstrahlung in the decay of\nparticles and resonances has been available with an interface to the C++ HepMC\nevent record. The main purpose of the present paper is to document the\ntechnical aspects of the PHOTOS Monte Carlo installation and present version\nuse. A multitude of test results and examples are distributed together with the\nprogram code.\n The PHOTOS C++ physics precision is better than its FORTRAN predecessor and\nmore convenient steering options are also available. An algorithm for the event\nrecord interface necessary for process dependent photon emission kernel is\nimplemented. It is used in Z and W decays for kernels of complete first order\nmatrix elements of the decays. Additional emission of final state lepton pairs\nis also available.\n Physics assumptions used in the program and properties of the solution are\nreviewed. In particular, it is explained how the second order matrix elements\nwere used in design and validation of the program iteration procedure. Also, it\nis explained that the phase space parametrization used in the program is exact.", "category": "hep-ph" }, { "text": "Characteristics of Cherenkov Radiation in Naturally Occuring Ice: We revisit the theory of Cherenkov radiation in uniaxial crystals.\nHistorically, a number of flawed attempts have been made at explaining this\nradiation phenomenon and a consistent error-free description is nowhere\navailable. We apply our calculation to a large modern day telescope - IceCube.\nBeing located at the Antarctica, this detector makes use of the naturally\noccuring ice as a medium to generate Cherenkov radiation. However, due to the\nhigh pressure at the depth of the detector site, large volumes of hexagonal ice\ncrystals are formed. We calculate how this affects the Cherenkov radiation\nyield and angular dependence. We conclude that the effect is small, at most\nabout a percent, and would only be relevant in future high precision\ninstruments like e.g. Precision IceCube Next Generation Upgrade (PINGU). For\nradio-Cherenkov experiments which use the presence of a clear Cherenkov cone to\ndetermine the arrival direction, any variation in emission angle will directly\nand linearly translate into a change in apparent neutrino direction. In\nclosing, we also describe a simple experiment to test this formalism, and\ncalculate the impact of anisotropy on light-yields from lead tungstate crystals\nas used, for example, in the CMS calorimeter at the CERN LHC.", "category": "hep-ph" }, { "text": "Spinless Salpeter Equation: Some (Semi-) Analytical Approaches: Several techniques for deriving semianalytical bounds on the energy\neigenvalues of the spinless Salpeter equation and for estimating the quality of\nthe corresponding approximate eigenstates are reviewed.", "category": "hep-ph" }, { "text": "The Cosmological Moduli Problem and Preheating: Many models of supersymmetry breaking, in the context of either supergravity\nor superstring theories, predict the presence of particles with\nPlanck-suppressed couplings and masses around the weak scale. These particles\nare generically called moduli. The excessive production of moduli in the early\nUniverse jeopardizes the successful predictions of nucleosynthesis. In this\npaper we show that the efficient generation of these dangerous relics is an\nunescapable consequence of a wide variety of inflationary models which have a\npreheating stage. Moduli are generated as coherent states in a novel way which\ndiffers from the usual production mechanism during parametric resonance. The\ncorresponding limits on the reheating temperature are often very tight and more\nsevere than the bound of 10^9 GeV coming from the production of moduli via\nthermal scatterings during reheating.", "category": "hep-ph" }, { "text": "$0^{+}$ fully-charmed tetraquark states: Motivated by the LHCb's new observation of structures in the $J/\\psi$-pair\ninvariant mass spectrum, for which could be classified as possible\n$cc\\bar{c}\\bar{c}$ tetraquark candidates, we systematically study $0^{+}$\nfully-charmed tetraquark states through QCD sum rules. Making the development\nof calculation techniques to fourfold heavy hadronic systems, four different\nconfiguration currents with $0^{+}$ are considered and vacuum condensates up to\ndimension $6$ are included in the operator product expansion (OPE). Finally,\nmass values acquired for $0^{+}$ $cc\\bar{c}\\bar{c}$ tetraquark states agree\nwell with the experimental data of the broad structure, which supports that it\ncould be a $0^{+}$ fully-charmed tetraquark state.", "category": "hep-ph" }, { "text": "Pomeron structure functions from HERA to Tevatron and LHC: The proton diffractive structure function $F_2^{D(3)}$ measured in the H1 and\nZEUS experiments at HERA are analysed in terms of perturbative QCD in the\nperspective of the QCD extrapolation to the Tevatron and the LHC. It is shown\nthat both data sets can be well described by a QCD analysis in which point-like\nparton distributions, evolving according to the next-leading DGLAP equations,\nare assigned to the leading and sub-leading Regge exchanges. For present data\nfrom H1 and ZEUS the gluon distributions are found to be quite different and we\ngive the corresponding sets of quark and gluon parton distributions for the\nPomeron, extracted from the two experiments. An extrapolation to the Tevatron\nrange is compared with CDF data on single diffraction. Conclusions on\nfactorization breaking between HERA and Tevatron critically depend on whether\nH1 (strong violation) or ZEUS (compatibility at low $\\beta$) fits are taken\ninto account. Using the double Pomeron formulation in central diffractive dijet\nproduction we show that the Tevatron mass fraction is much sensitive to the\nhigh $\\beta$ tail of the gluon in the Pomeron, suggesting a new way of handling\nthe otherwise badly known gluon distribution in the Pomeron. Extrapolation of\nthe fits to very high $Q^2$ are given since they will be relevant for QCD and\ndiffraction studies at the LHC.", "category": "hep-ph" }, { "text": "Non standard neutrino interactions at LEP2 and the LHC: We consider Non-Standard neutrino Interactions (NSI) connecting two neutrinos\nwith two first-generation fermions ($e, u$ or $d$), which we assume to arise at\nat dimension eight due to New Physics. The coefficient is normalised as $4\n\\epsilon G_F/\\sqrt{2}$. We explore signatures of NSI-on-electrons at LEP2, and\nof NSI-on-quarks at the LHC, treating the NSI as contact interactions at both\nenergies. In models where the coefficients of dangerous dimension six operators\nare suppressed by cancellations, LEP2 provides interesting bounds on NSI\noperators ($\\epsilon \\lsim 10^{-2} - 10^{-3}$), which arise because $\\sqrt{s}\n\\sim 200$ GeV, and the cancellation applied at zero momentum transfer. At the\nLHC, we use the Equivalence Theorem, which relates the longitudinal $W$ to the\nHiggs, to estimate the rate for $\\bar{q} q W^+W^- e_\\alpha^+ e_\\beta^-$ induced\nby NSI. We find that the cross-section is small, but that the outgoing\nparticles have very high $p_T > 400$ GeV, which reduces the issue of\nbackgrounds. In a conservative scenario, we find that the LHC at 14 TeV and\nwith 100 fb$^{-1}$ of data would have a sensitivity to $\\epsilon \\gsim 3 \\times\n10^{-3}$.", "category": "hep-ph" }, { "text": "$W$ mass in a model with vector-like leptons and $U(1)^\\prime$: We study the effects of vector-like leptons on the $W$ boson mass in a model\nwith a vector-like $U(1)^\\prime$ gauge symmetry. This model provides\nsimultaneous explanations for the recent anomalies in the muon anomalous\nmagnetic moment and the semi-leptonic decays of $B$ mesons. We found that the\nrecent result of the $W$ boson mass precise measurement at CDF can be explained\nif the charged (neutral) vector-like lepton is lighter than 250 (80) GeV. The\nlight vector-like leptons may not be excluded by collider experiments if these\ndecay to a physical mode of the $U(1)^\\prime$ breaking scalar field.", "category": "hep-ph" }, { "text": "Density Fluctuations as Signature of a Non--Equilibrium First Order\n Phase Transition: We show that in the presence of spinodal instabilities which develop at a\nfirst order phase transition, the fluctuations of conserved charges can be as\nstrong as those at the critical end point (CEP). In particular, the net baryon\nnumber susceptibility diverges as the system crosses the isothermal spinodal\nlines. This indicates that charge density fluctuations can be used not only to\nprobe the CEP but also the non--equilibrium first order chiral phase transition\nin heavy ion collisions.", "category": "hep-ph" }, { "text": "Precision Electroweak Data: Phenomenological Analysis: The precision electroweak program, including weak neutral current (WNC),\n$Z$-pole, and high energy collider experiments, has been the primary prediction\nand test of electroweak unification. It has established that the standard model\n(SM) is correct and unique to first approximation, establishing the gauge\nprinciple as well as the SM gauge group and representations; shown that the SM\nis correct at loop level, confirming the basic principles of renormalizable\ngauge theory and allowing the successful prediction or constraint on $m_t$,\n$\\alpha_s$, and $M_H$; severely constrained new physics at the TeV scale, with\nthe ideas of unification strongly favored over TeV-scale compositeness; and\nyielded precise values for the gauge couplings, consistent with\n(supersymmetric) gauge unification.", "category": "hep-ph" }, { "text": "Analysis of the higher twist GTMD $F_{31}$ for proton in the light-front\n quark-diquark model: In the light-front quark-diquark model (LFQDM), the higher twist generalized\ntransverse momentum dependent distribution (GTMD) $F_{31}(x, {\\bf p_\\perp},{\\bf\n\\Delta_\\perp})$ for the proton has been analyzed. We have derived the GTMD\noverlap equation by the analysis of GTMD correlator, employing the light-front\nwave functions in both the scalar and vector diquark situations. With the\nrelevant 2-D and 3-D figures, the behavior of GTMD $F_{31}(x, {\\bf\np_\\perp},{\\bf \\Delta_\\perp})$ with variations in its variables has been\nillustrated. Further, on applying the transverse momentum dependent\ndistribution (TMD) limit on GTMD $F_{31}(x, {\\bf p_\\perp},{\\bf \\Delta_\\perp})$,\nthe expression of TMD $f_3(x, {\\bf p_\\perp})$ has been obtained.", "category": "hep-ph" }, { "text": "Higgs boson pair production via gluon fusion at N$^3$LO in QCD: We present next-to-next-to-next-to-leading order (N$^3$LO) QCD predictions\nfor the Higgs boson pair production via gluon fusion at hadron colliders in the\ninfinite top-quark mass limit. Besides the inclusive total cross sections at\nvarious collision energies, we also provide the invariant mass distribution of\nthe Higgs boson pair. Our results show that the N$^3$LO QCD corrections enhance\nthe next-to-next-to-leading order cross section by $3.0\\%$ ($2.7\\%$) at\n$\\sqrt{s}=13~(100)$ TeV, while the scale uncertainty is reduced substantially\nbelow $3\\%$ ($2\\%$). We also find that a judicious scale choice can\nsignificantly improve the perturbative convergence. For the invariant mass\ndistribution, our calculation demonstrates that the N$^3$LO corrections improve\nthe scale dependence but almost do not change the shape.", "category": "hep-ph" }, { "text": "Strong decays of the charmed mesons $D_1^*(2680)$, $D^*_3(2760)$,\n $D_2^*(3000)$: In this article, we assign the higher charmed mesons $D^*_1(2680)$,\n$D_3^*(2760)$ and $D_2^*(3000)$ to be the 2S $1^-$, 1D $3^-$ and 1F $2^+$\nstates, respectively, and study the two-body strong decays to the ground state\ncharmed mesons and light pseudoscalar mesons with the heavy meson effective\ntheory. We obtain the ratios among the strong decays, which can be confronted\nto the experimental data in the future and shed light on the nature of those\nhigher charmed mesons.", "category": "hep-ph" }, { "text": "Exclusive Radiative Higgs Decays as Probes of Light-Quark Yukawa\n Couplings: We present a detailed analysis of the rare exclusive Higgs-boson decays into\na single vector meson and a photon and investigate the possibility of using\nthese processes to probe the light-quark Yukawa couplings. We work with an\neffective Lagrangian with modified Higgs couplings to account for possible\nnew-physics effects in a model-independent way. The h->V\\gamma{} decay rate is\ngoverned by the destructive interference of two amplitudes, one of which\ninvolves the Higgs coupling to the quark anti-quark pair inside the vector\nmeson. We derive this amplitude at next-to-leading order in \\alpha_s using QCD\nfactorization, including the resummation of large logarithmic corrections and\naccounting for the effects of flavor mixing. The high factorization scale\n\\mu~m_h ensures that our results are rather insensitive to the hadronic\nparameters characterizing the light-cone distribution amplitude of the vector\nmeson. The second amplitude arises from the loop-induced effective\nh\\gamma\\gamma* and h\\gamma Z* couplings, where the off-shell gauge boson\nconverts into the vector meson. We devise a strategy to eliminate theoretical\nuncertainties related to this amplitude to almost arbitrary precision. This\nopens up the possibility to probe for O(1) modifications of the c- and b-quark\nYukawa couplings and O(30) modifications of the s-quark Yukawa coupling in the\nhigh-luminosity LHC run. In particular, we show that measurements of the ratios\nBr(h->\\Upsilon(nS)\\gamma)/Br(h->\\gamma\\gamma) and Br(h->bb)/Br(h->\\gamma\\gamma)\ncan provide complementary information on the real and imaginary parts of the\nb-quark Yukawa coupling. More accurate measurements would be possible at a\nfuture 100 TeV proton-proton collider.", "category": "hep-ph" }, { "text": "Ultra-high energy neutrino scattering: Estimates are made of the ultra-high energy neutrino cross sections based on\nan extrapolation to very small Bjorken x of the logarithmic Froissart\ndependence in x shown previously to provide an excellent fit to the measured\nproton structure function F_2^p(x,Q^2) over a broad range of the virtuality\nQ^2. Expressions are obtained for both the neutral current and the charged\ncurrent cross sections. Comparison with an extrapolation based on perturbative\nQCD shows good agreement for energies where both fit data, but our rates are as\nmuch as a factor of 10 smaller for neutrino energies above 10^9 GeV, with\nimportant implications for experiments searching for extra-galactic neutrinos.", "category": "hep-ph" }, { "text": "Constraints on cosmic-ray boosted DM in CDEX-10: Dark matter (DM) direct detection experiments have been setting strong limits\non the DM-nucleon scattering cross section at the DM mass above a few GeV, but\nleave large parameter space unexplored in the low mass region. DM is likely to\nbe scattered and boosted by relativistic cosmic rays in the expanding universe\nif it can generate nuclear recoils in direct detection experiments to offer\nobservable signals. Since low energy threshold detectors using Germanium have\nprovided good constraints on ordinary halo GeV-scale DM, it is necessary to\nre-analyze 102.8 kg$\\times$day data in the CDEX-10 experiment assuming that DM\nis boosted by cosmic rays. For the DM mass range 1 keV $ V gamma, with a\nvector meson K* or rho in the final state, and the double radiative modes B_s\n-> gamma gamma and B_d -> gamma gamma. At quark level, all these decays are\ngoverned by the flavour-changing neutral-current b -> s gamma or b -> d gamma\ntransitions, which appear at the one-loop level in the Standard Model. Such\nprocesses allow us to study CP violation and the interplay of strong and\nelectroweak interactions, to determine parameters of the CKM matrix, and to\nsearch for New Physics. The exclusive decays are experimentally better\naccessible, but pose more problems for the theoretical analysis. The\nheavy-quark limit m_b >> Lambda_QCD, however, allows to systematically separate\nperturbatively calculable hard scattering kernels from nonperturbative form\nfactors and universal light-cone distribution amplitudes. For the B -> V gamma\ndecays we evaluate the leading Lambda_QCD/m_b contributions complete to\nnext-to-leading order in QCD, including also QCD penguin operators. The double\nradiative B -> gamma gamma decays are analyzed with leading-logarithmic\naccuracy. We predict branching ratios, CP and isospin asymmetries, and estimate\nU-spin breaking effects for B -> K* gamma and B -> rho gamma. For the B ->\ngamma gamma decays we give numerical results for branching ratios and CP\nasymmetries.", "category": "hep-ph" }, { "text": "Radiative corrections to the Dalitz plot of K_{l3}^0 decays: A model-independent expression for the Dalitz plot of semileptonic decays of\nneutral kaons, K_{l3}^0, including radiative corrections to order\n(\\alpha/\\pi)(q/M_1), where q is the momentum transfer and M_1 is the mass of\nthe kaon, is presented. The model dependence of radiative corrections is kept\nin a general form within this approximation, which is suitable for\nmodel-independent experimental analyses. Expressions for bremsstrahlung\nradiative corrections are presented in two forms: one with the triple integral\nover the kinematical variables of the photon ready to be performed numerically\nand the other one in a fully analytical form. The final result is restricted to\nthe so-called three-body region of the Dalitz plot and it is not compromised to\nfixing the values of the form factors at predetermined values.", "category": "hep-ph" }, { "text": "Ansatz for small FCNC with a non-universal $Z^\\prime$: It is well known that a non-universal $Z^\\prime$ induces tree-level FCNC\nwhich are severely constrained by experiment, most notably meson mixing. We\npoint out that there is a class of models, with a down-quark mass matrix of the\nGeorgi-Jarlskog form, in which the FCNC in the down-type quark sector vanish or\nare strongly suppressed. The largest FCNC in these models would occur in the\n$tc$ transition with a strength comparable to $V_{ts}$.", "category": "hep-ph" }, { "text": "The Dualized Standard Model and its Applications---an Interim Report: Based on a nonabelian generalization of electric-magnetic duality, the\nDualized Standard Model (DSM) suggests a natural explanation for exactly 3\ngenerations of fermions as the `dual colour' $\\widetilde{SU}(3)$ symmetry\nbroken in a particular manner. The resulting scheme then offers on the one hand\na fermion mass hierarchy and a perturbative method for calculating the mass and\nmixing parameters of the Standard Model fermions, and on the other testable\npredictions for new phenomena ranging from rare meson decays to ultra-high\nenergy cosmic rays. Calculations to 1-loop order gives, at the cost of\nadjusting only 3 real parameters, values for the following quantities all\n(except one) in very good agreement with experiment: the quark CKM matrix\nelements $|V_{rs}|$, the lepton CKM matrix elements $|U_{rs}|$, and the second\ngeneration masses $m_c, m_s, m_\\mu$. This means, in particular, that it gives\nnear maximal mixing $U_{\\mu3}$ between $\\nu_\\mu$ and $\\nu_\\tau$ as observed by\nSuperKamiokande, Kamiokande and Soudan, while keeping small the corresponding\nquark angles $V_{cb}, V_{ts}$. In addition, the scheme gives (i) rough\norder-of-magnitude estimates for the masses of the lowest generation, (ii)\npredictions for low energy FCNC effects such as $K_L \\to e \\mu$, (iii) a\npossible explanation for the long-standing puzzle of air showers beyond the GZK\ncut-off. All these together, however, still represent but a portion of the\npossible physical consequences derivable from the DSM scheme the majority of\nwhich are yet to be explored.", "category": "hep-ph" }, { "text": "NOvA and T2K: The race for the neutrino mass hierarchy: The determination of the ordering of the neutrino masses (the hierarchy) is\nprobably a crucial prerequisite to understand the origin of lepton masses and\nmixings and to establish their relationship to the analogous properties in the\nquark sector. Here, we follow an alternative strategy to the usual\nneutrino--antineutrino comparison in long baseline neutrino oscillation\nexperiments: we exploit the combination of the neutrino-only data from the NOvA\nand the T2K experiments by performing these two off-axis experiments at\ndifferent distances but at the same $/L$, where $$ is the mean neutrino\nenergy and $L$ is the baseline. This would require a minor adjustment to the\nproposed off-axis angle for one or both of the proposed experiments.", "category": "hep-ph" }, { "text": "A rotating string model versus baryon spectra: We continue our program of describing hadrons as rotating strings with\nmassive endpoints. In this paper we propose models of baryons and confront them\nwith the baryon Regge trajectories. We show that these are best fitted by a\nmodel of a single string with a quark at one endpoint and a diquark at the\nother. This model is preferred over the Y-shaped string model with a quark at\neach endpoint. We show how the model follows from a stringy model of the\nholographic baryon which includes a baryonic vertex connected with N_c strings\nto flavor probe branes. From fitting to baryonic data we find that there is no\nclear evidence for a non-zero baryonic vertex mass, but if there is such a mass\nit should be located at one of the string endpoints. The available baryon\ntrajectories in the angular momentum plane (J,M^2), involving light, strange,\nand charmed baryons, are rather well fitted when adding masses to the string\nendpoints, with a single universal slope of 0.95 GeV^-2. Most of the results\nfor the quark masses are then found to be consistent with the results extracted\nfrom the meson spectra in a preceding paper, where the value of the slope\nemerging from the meson fits was found to be 0.90 GeV^-2. In the plane of\nquantum radial excitations, (n,M^2), we also find a good agreement between the\nmeson and baryon slopes. The flavor structure of the diquark is examined, where\nour interest lies in particular on baryons composed of more than one quark\nheavier than the u and d quarks. For these baryons we present a method of\nchecking the holographic interpretation of our results.", "category": "hep-ph" }, { "text": "Quark-Lepton Mass Relation and CKM mixing in an A4 Extension of the\n Minimal Supersymmetric Standard Model: An interesting mass relation between down type quarks and charged leptons has\nbeen recently predicted within a supersymmetric SU(3)_c \\times SU(2)_L \\times\nU(1)_Y model based on the A4 flavor symmetry. Here we propose a simple\nextension which provides an adequate full description of the quark sector. By\nadding a pair of vector-like up-quarks we show how the CKM entries Vub, Vcb,\nVtd and Vts arise from deviations of the unitarity. We perform an analysis\nincluding the most relevant observables in the quark sector, such as\noscillations and rare decays of Kaons, Bd and Bs mesons. In the lepton sector,\nmodel predicts an inverted hierarchy for the neutrino masses leading to a\npotentially observable rate of neutrinoless double beta decay.", "category": "hep-ph" }, { "text": "Implementing the exact kinematical constraint in the saturation\n formalism: We revisit the issue of the large negative next-to-leading order (NLO) cross\nsection for single inclusive hadron production in $pA$ collisions in the\nsaturation formalism. By implementing the exact kinematical constraint in the\nmodified dipole splitting functions, two additional positive NLO correction\nterms are obtained. In the asymptotic large $k_\\perp$ limit, we analytically\nshow that these two terms become as large as the negative NLO contributions\nfound in our previous calculation. Furthermore, the numerical results\ndemonstrate that the applicable regime of the saturation formalism can be\nextended to a larger $k_\\perp$ window, where the exact matching between the\nsaturation formalism (in the asymptotic $k_\\perp$ regime) and the collinear\nfactorization calculations will have to be performed separately. In addition,\nafter significantly improving the numerical accuracy of the NLO correction, we\nobtain excellent agreement with the LHC and RHIC data for forward hadron\nproductions.", "category": "hep-ph" }, { "text": "Data Unfolding in W mass measurements at LEP2: The use of an unfolding procedure is proposed as an alternative method of\nextracting the $W$ boson mass from the data measured at LEP2, which may improve\nthe accuracy of this measurement. The benefits of the direct unfolding method\nbased on the Singular Value Decomposition of the response matrix are\ndemonstrated on the example of W mass determination from the charged lepton\nenergy spectra.", "category": "hep-ph" }, { "text": "Charm and Bottom Quark Masses from Perturbative QCD: Using a new result for the first moment of the hadronic production cross\nsection at order ${\\cal O}(\\alpha_s^3)$, and new data on the $J/\\psi$ and\n$\\psi'$ resonances for the charm quark, we determine the \\msb masses of the\ncharm and bottom quarks to be $\\bar{m}_c(\\bar{m}_c) = 1.295 \\pm 0.015$ GeV and\n$\\bar{m}_b(\\bar{m}_b) = 4.205 \\pm 0.058$ GeV. We assume that the continuum\ncontribution to the sum rules is adequately described by pQCD. While we observe\na large reduction of the perturbative error, the shifts induced by the\ntheoretical input are very small. The main change in the central value of $m_c$\nis related to the experimental data. On the other hand, the value of $m_b$ is\nnot changed by our calculation to the assumed precision.", "category": "hep-ph" }, { "text": "Jet grooming through reinforcement learning: We introduce a novel implementation of a reinforcement learning (RL)\nalgorithm which is designed to find an optimal jet grooming strategy, a\ncritical tool for collider experiments. The RL agent is trained with a reward\nfunction constructed to optimize the resulting jet properties, using both\nsignal and background samples in a simultaneous multi-level training. We show\nthat the grooming algorithm derived from the deep RL agent can match\nstate-of-the-art techniques used at the Large Hadron Collider, resulting in\nimproved mass resolution for boosted objects. Given a suitable reward function,\nthe agent learns how to train a policy which optimally removes soft wide-angle\nradiation, allowing for a modular grooming technique that can be applied in a\nwide range of contexts. These results are accessible through the corresponding\nGroomRL framework.", "category": "hep-ph" }, { "text": "Large Neutrino Mixing in Grand Unified Theories: A non-minimal, semi-realistic version of supersymmetric SU(5) grand unified\ntheory is discussed. The solution of the doublet-triplet splitting problem\nleads to a better agreement between the predicted and observed values of the\nlow-energy strong coupling constant and to a prolongation of the proton\nlifetime. A U(1) flavor symmetry allows to accommodate a realistic mass\nspectrum in the charged and in the neutral fermion sectors and protects\ndoublet-triplet splitting and proton decay from dangerous radiative corrections\nor non-renormalizable operators.", "category": "hep-ph" }, { "text": "Oblique corrections from less-Higgsless models in warped space: The Higgsless model in warped extra dimension is reexamined. Dirichlet\nboundary conditions on the TeV brane are replaced with Robin boundary\nconditions which are parameterized by a mass parameter $M$. We calculate the\nPeskin-Takeuchi precision parameters $S$, $T$ and $U$ at tree level. We find\nthat to satisfy the constraints on the precision parameters at $99 \\%$ [$95\n\\%$] confidence level (CL) the first Kaluza-Klein excited $Z$ boson, $Z'$,\nshould be heavier than 5 TeV [8 TeV]. The Magnitude of $M$, which is infinitely\nlarge in the original model, should be smaller than 200 GeV (70 GeV) for the\ncurvature of the warped space $R^{-1}=10^{16}$ GeV ($10^{8}$ GeV) at $95\\%$ CL.\nIf the Robin boundary conditions are induced by the mass terms localized on the\nTeV brane, from the $99\\%$ [$95\\%$] bound we find that the brane mass\ninteractions account for more than $97\\%$ [$99\\%$] of the masses of $Z$ and $W$\nbosons. Such a brane mass term is naturally interpreted as a vacuum expectation\nvalue of the Higgs scalar field in the standard model localized on the TeV\nbrane. If so, the model can be tested by precise measurements of $HWW$, $HZZ$\ncouplings and search for 1st Kaluza-Klein excited states.", "category": "hep-ph" }, { "text": "Radiative Decays, Nonet Symmetry and SU(3) Breaking: We re-examine the problem of simultaneously describing in a consistent way\nall radiative and leptonic decays of light mesons (V -> P gamma, P -> V gamma,\nP -> gamma gamma, V -> e^+ e^-). For this purpose, we rely on the Hidden Local\nSymmetry model in both its anomalous and non--anomalous sectors. We show that\nthe SU(3) symmetry breaking scheme proposed by Bando, Kugo and Yamawaki,\nsupplemented with nonet symmetry breaking in the pseudoscalar sector, allows\none to reach a nice agreement with all data, except for the K^{*+/-} radiative\ndecay. An extension of this breaking pattern allows one to account for this\nparticular decay mode too. Considered together, the whole set of radiative\ndecays provides a pseudoscalar mixing angle theta_P ~ -11^o and a value for\ntheta_V which is ~ 3^o from that of ideal mixing. We also show that it is\nimpossible, in a practical sense, to disentangle the effects of nonet symmetry\nbreaking and those of glue inside the eta', using only light meson decays.", "category": "hep-ph" }, { "text": "Proton-antiproton annihilation into massive leptons: We extend previous calculations of polarization observables for the\nannihilation reaction $\\bar p +p\\to \\ell^{-}+\\ell^{+}$ to the case of heavy\nleptons, such as the $\\tau$-lepton. We consider the case when the beam and/or\nthe target are polarized, as well as the polarization of the outgoing leptons.\nWe give the dependence of the unpolarized cross section, angular asymmetry, and\nvarious polarization observables on the relevant kinematical variables in the\ncenter of mass and in the laboratory system, with particular attention to the\neffect of the mass induced terms.", "category": "hep-ph" }, { "text": "Recent developments on direct $CP$ violation in the kaon system and\n connection to $K \\to \u03c0\u03bd\\bar\u03bd$ measurements: The first lattice result from the RBC and UKQCD Collaborations and improved\nperturbative calculations of $\\varepsilon^{\\prime}_K / \\varepsilon_K$ have\nimplied that the Standard-Model (SM) expectation deviates from measured values\nat the $2.8\\,\\sigma$ level. Since $\\varepsilon^{\\prime}_K / \\varepsilon_K$\ncomes from $CP$-violating FCNC and is significantly suppressed in the SM, the\ndiscrepancy can be explained easily in several new physics (NP) models. In this\ncontribution, it is shown that correlations with the other rare decays,\nespecially $K\\to \\pi \\nu \\overline{\\nu}$ and $K_S \\to \\mu^+ \\mu^-$, are crucial\nfor discrimination of the NP models. These channels can be probed precisely in\nthe future by the NA62 and KOTO experiments for $K\\to \\pi \\nu \\overline{\\nu}$\nand LHCb experiment for $K_S \\to \\mu^+ \\mu^-$.", "category": "hep-ph" }, { "text": "Revisiting constraints on 3+1 active-sterile neutrino mixing using\n IceCube data: Recent IceCube search results for sterile neutrino increased tension between\nthe combined appearance and disappearance experiments. On the other hand,\nMiniBooNE latest data confirms at $4.9\\sigma$ CL the short-baseline oscillation\nanomaly. We analyze published IceCube data based on two different\nactive-sterile mixing schemes using one additional sterile neutrino flavor. We\npresent exclusion regions in the parameter ranges $0.01 \\le \\sin^2 \\theta_{24}\n\\le 0.1$ and $0.1~{\\rm eV}^2 \\le \\Delta m^2_{42} \\le 10~{\\rm eV}^2$ for the\nmass-mixing and flavor-mixing schemes. Under the more conservative mass-mixing\nscheme, $3\\sigma$ CL allowed regions for the appearance experiment and\nMiniBooNE latest result are excluded at $\\gtrsim 3\\sigma$ CL. In case of\nless-restrictive flavor-mixing scheme, results from the appearance experiments\nare excluded at $\\gtrsim 2\\sigma$ CL. We also find that including prompt\ncomponent of the atmospheric neutrino flux relaxes constraints on sterile\nmixing for $\\Delta m^2_{42} \\gtrsim 1~{\\rm eV}^2$.", "category": "hep-ph" }, { "text": "Beyond The Standard Model: This Time for Real: The value of the neutrino mass reported by the SuperK collaboration fits\nbeautifully into the framework of gauge theory unification. Here I justify this\nclaim, and review the other main reasons to believe in that framework.\nSupersymmetry and SO(10) symmetry are important ingredients; nucleon\ninstability is a dramatic consequence.", "category": "hep-ph" }, { "text": "From Cosmic Inflation and Matter Creation to Dark Matter -- Journey of\n the Inflaton?: A scenario of the inflaton evolution from cosmic inflation and matter\ncreation to dark matter/dark energy today is presented. To start with, a model\nof the inflationary phase of the inflaton is introduced. The inflaton rolls\ndown a hilltop potential along with matter creation being dragged down by the\npresence of matter. Presence of matter provides a mechanism to stop universe's\nacceleration and hence the inflationary phase. The model predictions for the\nstandard metrics are fully consistent with the current CMB limits. The\npotential could in principle be extended to complete a potential hill\nsubsequent to inflation. The evolution of the inflaton from the inflationary\nphase to radiation/matter dominated eras and to current times can be inferred\nqualitatively following the evolution of its equation of state parameter.\nExistence of solutions to its dynamics, tracking matter as it evolves to\ncurrent times, provides a plausible reasoning for the relative order of\nmagnitudes of the cosmological parameters, in particular to the relative\nabundance of dark matter today.", "category": "hep-ph" }, { "text": "Phenomenology of epsilon_K in the top era: Todays key information on the shape of the unitarity triangle is obtained\nfrom the well-measured quantity epsilon_K characterizing the CP-violation in\n|Delta S|=2 transitions. The phenomenological analysis requires the input of\nfour key quantities: The magnitudes of the CKM elements V_cb and V_ub, the top\nquark mass and the non-perturbative parameter B_K. In the recent years all of\nthem have been determined with increasing precision. In order to keep up with\nthis progress the |Delta S|=2-hamiltonian had to be obtained in the\nnext-to-leading order (NLO) of renormalization group improved perturbation\ntheory. I present the NLO results for the QCD coefficients eta_1 and eta_3,\nwhich have been calculated by Stefan Herrlich and myself, and briefly sketch\nsome aspects of the calculation. Then I give an update of the Unitarity\nTriangle using the summer 1996 data for the input parameters. The results for\nthe improved Wolfenstein parameters rho-bar and eta-bar and the CKM phase delta\nare -0.21 < rho-bar < 0.22, 0.27 < eta-bar < 0.43 and 57 degrees < delta < 122\ndegrees. The range for the quantity sin(2 beta) entering CP asymmetries in\nB-decays is found as 0.46 < sin(2 beta) < 0.79. The given ranges correspond to\none standard deviation in the input parameters. Finally I briefly discuss the\nK_L-K_S mass difference.", "category": "hep-ph" }, { "text": "The Higgs sector of the complex MSSM at two-loop order: QCD\n contributions: Results are presented for the leading two-loop contributions of O(alpha_t\nalpha_s) to the masses and mixing effects in the Higgs sector of the MSSM with\ncomplex parameters. They are obtained in the Feynman-diagrammatic approach\nusing on-shell renormalization. The full dependence on all complex phases is\ntaken into account. The renormalization of the appropriate contributions of the\nHiggs-boson sector and the scalar top and bottom sector is discussed. Our\nnumerical analysis for the lightest MSSM Higgs-boson mass is based on the new\ntwo-loop corrections, supplemented by the full one-loop result. The corrections\ninduced by the phase variation in the scalar top sector are enhanced by the\ntwo-loop contributions. We find that the corresponding shift in M_h1 can amount\nto 5 GeV.", "category": "hep-ph" }, { "text": "Hard Diffraction in Pythia 8: We present an overview of the options for diffraction implemented in the\ngeneral--purpose event generator Pythia 8. We review the existing model for\nlow-- and high--mass soft diffraction and present a new model for hard\ndiffraction in pp and ppbar collisions. Both models uses the Pomeron approach\npioneered by Ingelman and Schlein, factorising the single diffractive cross\nsection into a Pomeron flux and a Pomeron PDF. The model for hard diffraction\nis implemented as a part of the multiparton interactions framework, thereby\nintroducing a dynamical rapidity gap survival probability that explicitly\nbreaks factorisation.", "category": "hep-ph" }, { "text": "CGC predictions for p+A collisions at the LHC and signature of QCD\n saturation: We present various predictions for the upcoming p+Pb collisions at \\sqrt{S}=5\nTeV within the color glass condensate (CGC) formalism, including single\ninclusive charged hadron production, single inclusive prompt photon production,\ndirect photon production, charged hadron multiplicity distribution and\nphoton-hadron azimuthal correlations. Using the running-coupling\nBalitsky-Kovchegov evolution equation for calculating various observables, we\nshow that the main source of uncertainties is due to less constrained initial\nnuclear saturation scale. This gives rise to rather large theoretical\nuncertainties for nuclear modification factor R_{pA} at the LHC. Nevertheless,\nwe propose a simple scheme in which one can still test the main dynamics of the\nCGC/saturation in p+A collisions at the LHC.", "category": "hep-ph" }, { "text": "Finding the CP-Violating Higgs Bosons at e^+e^- Colliders: We discuss a general two-Higgs-doublet model with CP violation in the Higgs\nsector. In general, the three neutral Higgs fields of the model all mix and the\nresulting physical Higgs bosons have no definite CP properties. We derive a new\nsum rule relating Yukawa and Higgs-Z couplings which implies that a neutral\nHiggs boson cannot escape detection at an e^+e^- collider if it is\nkinematically accessible in Z+Higgs, $b\\anti b+$Higgs and $t\\anti t+$Higgs\nproduction, irrespective of the mixing angles and the masses of the other\nneutral Higgs bosons. We also discuss modifications of the sum rules and their\nphenomenological consequences in the case when the two-doublet Higgs sector is\nextended by adding one or more singlets.", "category": "hep-ph" }, { "text": "Study of Single W production in e-gamma collisions through the decay\n lepton spectrum to probe gamma-WW couplings: We investigate the effect of anomalous gamma-W-W couplings in e-gamma --> nu\nW through the angular and energy spectrum of the secondary leptons. Within the\nnarrow-width approximation, a semi-analytical study of the secondary lepton\nenergy-angle double distribution is considered. Utility of observables derived\nfrom this is demonstrated by considering the anomalous coupling,\ndelta-kappa-gamma. Results of our investigation for typical ILC machine\nconsidered at Ecm = 300-1000 GeV re-affirms potential of this collider as a\nprecision machine.", "category": "hep-ph" }, { "text": "Complementarity of $B\\to K^{(*)} \u03bc\\bar \u03bc$ and $B\\to K^{(*)} +\n \\mathrm{inv}$ for searches of GeV-scale Higgs-like scalars: The rare decays $B^+\\to K^+ \\mu\\bar \\mu$ and $B^0\\to K^{*0} \\mu\\bar\\mu$\nprovide the strongest constraints on the mixing of a light scalar with the\nHiggs boson for GeV-scale masses. The constraints sensitively depend on the\nbranching ratio to muons. Additional decay channels like an invisible partial\nwidth may substantially weaken the constraints. This scenario will be probed at\nBelle II in $B\\to K^{(*)} + \\mathrm{inv}$. We illustrate the complementarity of\nscalar decays to muons and invisible decays using the currently available\nresults of LHCb and BaBar. We provide two simple model realisations providing a\nsizeable invisible scalar width, one based on a real scalar and one based on a\n$U(1)_{B-L}$ gauge symmetry. In both examples the scalar decays into heavy\nneutral leptons which can be motivated by the seesaw mechanism for neutrino\nmasses.", "category": "hep-ph" }, { "text": "Physics Beyond the Standard Model: I present a brief overview of some exciting possibilities for physics Beyond\nthe Standard Model. I include short discussions of neutrino physics, the strong\nCP problem and axions, GUTs, large and warped extra dimensions, Little Higgs\nmodels and supersymmetry. The chances appear excellent that in the next few\nyears-- as the LHC era gets underway-- data from a bevy of experiments will\npoint the way to a new paradigm for the laws of physics as we know them.", "category": "hep-ph" }, { "text": "Matching between matrix elements and parton showers using a Leading-Log\n subtraction method in NLO-QCD: A new method to construct event-generators based on next-to-leading order QCD\nmatrix-elements and leading-logarithmic parton showers is proposed. Matrix\nelements of loop diagrams as well as those of a tree level can be generated\nusing an automatic system. A soft/collinear singularity is treated using a\nleading-log subtraction method. Higher order re-summation of the soft/collinear\ncorrection by the parton shower method is combined with the NLO matrix-element\nwithout any double-counting in this method.", "category": "hep-ph" }, { "text": "Bi-large neutrino mixing from bilinear R-parity violation with\n non-universality: We investigate how the bi-large mixing required by the recent neutrino data\ncan be accommodated in the supersymmetric standard model allowing bilinear\nR-parity violation and non-universal soft terms. In this scheme, the tree-level\ncontribution and the so-called Grossman-Haber one-loop diagrams are two major\nsources of the neutrino mass matrix. The relative size of these two\ncontributions falls into the right range to generate the atmospheric and solar\nneutrino mass hierarchy. On the other hand, the bi-large mixing is typically\nobtained by a mild tuning of input parameters to arrange a partial cancellation\namong various contributions.", "category": "hep-ph" }, { "text": "CP violation in meson decays: This is a written version of a series of lectures aimed at graduate students\nin the field of (theoretical and experimental) high energy physics. The main\ntopics covered are: (i) The flavor sector of the Standard Model and the\nKobayashi-Maskawa mechanism of CP violation; (ii) Formalism and theoretical\ninterpretation of CP violation in meson decays; (iii) K decays; (iv) D decays;\n(v) B decays: b -> c c-bar s, b -> s s-bar s, b -> u u-bar d and b -> c u-bar\ns, u c-bar s; (vi) CP violation as a probe of new physics and, in particular,\nof supersymmetry.", "category": "hep-ph" }, { "text": "Distinguishing split supersymmetry in Higgs signals at the Large Hadron\n Collider: We examine the possibility of detecting signals of split supersymmetry in the\nloop-induced decay h --> gamma gamma of the Higgs boson at the Large Hadron\nCollider, where charginos, as surviving light fermions of the supersymmetric\nspectrum, can contribute in the loop. We perform a detailed study of\nuncertainties in various parameters involved in the analysis, and thus the net\nuncertainty in the standard model prediction of the rate. After a thorough scan\nof the parameter space, taking all constraints into account, we conclude that\nit will be very difficult to infer about split supersymmetry from Higgs signals\nalone.", "category": "hep-ph" }, { "text": "Improved Intermittency Analysis of Single Event Data: The intermittency analysis of single event data (particle moments) in\nmultiparticle production is improved, taking into account corrections due to\nthe reconstruction of history of a particle cascade. This approach is tested\nwithin the framework of the $\\alpha$-model.", "category": "hep-ph" }, { "text": "Higgs production in association with a single top quark at the LHC: We present a detailed study of Higgs boson production in association with a\nsingle top quark at the LHC, at next-to-leading order accuracy in QCD. We\nconsider total and differential cross sections, at the parton level as well as\nby matching short distance events to parton showers, for both t-channel and\ns-channel production. We provide predictions relevant for the LHC at 13 TeV\ntogether with a thorough evaluation of the residual uncertainties coming from\nscale variation, parton distributions, strong coupling constant and heavy quark\nmasses. In addition, for t-channel production, we compare results as obtained\nin the 4-flavour and 5-flavour schemes, pinning down the most relevant\ndifferences between them. Finally, we study the sensitivity to a\nnon-standard-model relative phase between the Higgs couplings to the top quark\nand to the weak bosons.", "category": "hep-ph" }, { "text": "Two-loop perturbative corrections to the constrained effective potential\n in thermal QCD: In this paper, we compute the constrained QCD effective potential up to\ntwo-loop order with finite quark mass and chemical potential. We present the\nexplicit calculations by using the double line notation and analytical\nexpressions for massless quarks are obtained in terms of the Bernoulli\npolynomials or Polyakov loops. Our results explicitly show that the constrained\nQCD effective potential is independent on the gauge fixing parameter. In\naddition, as compared to the massless case, the constrained QCD effective\npotential with massive quarks develops a completely new term which is only\nabsent when the background field vanishes. Furthermore, we discuss the relation\nbetween the one- and two-loop constrained effective potential. The surprisingly\nsimple proportionality that exists in the pure gauge theories, however, is in\ngeneral no longer true when fermions are taken into account. On the other hand,\nfor high baryon density $\\mu_B$ and low temperature $T$, in the massless limit,\nwe do also find a similar proportionality between the one- and two-loop\nfermionic contributions in the constrained effective potential up to ${\\cal\nO}(T/\\mu_B)$.", "category": "hep-ph" }, { "text": "Single production of vector-like top partner decaying to $Wb$ in the\n leptonic channel at $ep$ colliders in the LHT model: In the littlest Higgs model with T-parity(LHT), we study the single\nproduction of vector-like top partner with the subsequent decay $T_{+}\\to Wb$\nin the leptonic channel at the $ep$ colliders. Focus on the LHeC ($ \\sqrt{s} $\n= 1.98 TeV) and FCC-eh ($ \\sqrt{s} $ = 5.29 TeV), we investigate the\nobservability of the single top partner production with the unpolarized and\npolarized electron beams, respectively. As a result, the statistical\nsignificance can be enhanced by the polarized electron beams. Under the current\nconstraints, the search for $T_{+}$ in the $Wb$ channel at the LHeC cannot\nprovide a stronger limit on the top partner mass. By contrast, the search for\nthe $T_{+}$ in this channel at the FCC-eh with polarized $ e^- $ beams can\nexclude the top partner mass up to 1350 GeV, 1500 GeV and 1565 GeV with\nintegrated luminosities of 100 fb$^{-1}$, 1000 fb$^{-1}$ and 3000 fb$^{-1}$ at\nthe 2$\\sigma$ level, which is an improvement with respect to the current\nindirect searches and the LHC direct searches. Furthermore, we also give an\nextrapolation to the high-luminosity LHC with $\\sqrt{s}=14$ TeV and $\nL=3000~\\rm{fb}^{-1} $. Our results show that the LHT model is still a natural\nsolution to the shortcomings of the electroweak and scalar sector although it\nhas been constrained severely.", "category": "hep-ph" }, { "text": "Comment on \" a unified scheme for flavored mesons and baryons\": We would comment on the results of the paper \"a unified scheme for flavored\nmesons and baryons\" (P.C.Vinodkumar, J.N.Panandya, V.M.Bannur, and\nS.B.Khadkikar Eur. Phys. J. A4(1999)83), and point out some inconsistencies and\nmistakes in the work for solving the Dirac equation. In terms of an example for\na single particle we investigate the reliability of the perturbative method for\ncomputing the Coulomb energy and discuss the contribution to the wavefunction\nat origin from the Coulomb potential. We conclude that the accuracy of their\nnumerical results needs to be reconsidered.", "category": "hep-ph" }, { "text": "Radiative tritium beta-decay and the neutrino mass: The shape of the electron energy spectrum in 3H beta-decay permits a direct\nassay of the absolute scale of the neutrino mass; a highly accurate theoretical\ndescription of the electron energy spectrum is necessary to the empirical task.\nWe update Sirlin's calculation of the outer radiative correction to nuclear\nbeta-decay to take into account the non-zero energy resolution of the electron\ndetector. In previous 3H beta-decay studies the outer radiative corrections\nwere neglected all together; only Coulomb corrections to the spectrum were\nincluded. This neglect artificially pushes m_nu^2 < 0 in a potentially\nsignificant way. We present a computation of the theoretical spectrum\nappropriate to the extraction of the neutrino mass in the sub-eV regime.", "category": "hep-ph" }, { "text": "Pentaquarks and Radially Excited Baryons: In this talk I report on a computation of the spectra of exotic pentaquarks\nand radial excitations of the low--lying ${1/2}^+$ and ${3/2}^+$ baryons in a\nchiral soliton model.", "category": "hep-ph" }, { "text": "Visible and dark matter from a first-order phase transition in a\n baryon-symmetric universe: The similar cosmological abundances observed for visible and dark matter\nsuggest a common origin for both. By viewing the dark matter density as a\ndark-sector asymmetry, mirroring the situation in the visible sector, we show\nthat the visible and dark matter asymmetries may have arisen simultaneously\nthrough a first-order phase transition in the early universe. The dark\nasymmetry can then be equal and opposite to the usual visible matter asymmetry,\nleading to a universe that is symmetric with respect to a generalised baryon\nnumber. We present both a general structure, and a precisely defined example of\na viable model of this type. In that example, the dark matter is atomic as well\nas asymmetric, and various cosmological and astrophysical constraints are\nderived. Testable consequences for colliders include a Z' boson that couples\nthrough the B-L charge to the visible sector, but also decays invisibly to dark\nsector particles. The additional scalar particles in the theory can mix with\nthe standard Higgs boson and provide other striking signatures.", "category": "hep-ph" }, { "text": "The electroweak chiral Lagrangian revisited: Using a manifestly gauge-invariant approach we show that the set of\nlow-energy constants in the electroweak chiral Lagrangian currently used in the\nliterature is redundant. In particular, by employing the equations of motion\nfor the gauge fields, one can choose to remove two low-energy constants which\ncontribute to the self-energies of the gauge bosons. The relation of this\nresult to the experimentally determined values for the oblique parameters S,T\nand U is discussed. We then evaluate the matching relation between\ngauge-invariant Green's functions in the full and the effective theory for the\ncase of the Standard Model with a heavy Higgs boson and compare the results for\nthe independent low-energy constants with those for a simple Technicolor model.\nSince the pattern of the low-energy constants is very different in these two\nmodels it may be misleading to mimic any strongly interacting symmetry breaking\nsector by a heavy Higgs boson. From our investigation we conclude that current\nelectroweak precision data do not really rule out such strongly interacting\nmodels.", "category": "hep-ph" }, { "text": "Searching for Charged Higgs Bosons via $e^+ e^- \\to H^+ H^- \\to c\\bar{b}\n \\bar{c}b $ at Linear Colliders: We study a search for the charged Higgs boson via\n $e^+e^- \\to H^+H^- \\to c\\bar{b}\\bar{c}b$ at the 500 GeV ILC. In a general two\nHiggs doublet model without $Z_2$ symmetry, extra Yukawa couplings $\\rho_{tt}$\nand $\\rho_{tc}$ can drive baryogenesis, but searches at the HL-LHC may still go\nempty-handed if the couplings are relatively weak. Taking $m_{H^+ } \\simeq m_H\n\\simeq m_A \\simeq 200$ GeV, with $\\rho_{tt}$, $\\rho_{tc}\\sim 0.1$ and no\n$h(125)$-$H$ mixing, $H^+ \\to c\\bar b$ decay is dominant, and the\n$c\\bar{b}\\bar{c}b$ final state is likely overwhelmed by QCD background at the\nLHC. We show that the electroweak production of $H^+ H^-$ at the ILC is\ndiscoverable with integrated luminosity of 1 ab$^{-1}$. Furthermore, we show\nthat $m_{H^+}$ can be extracted by requiring the two pairs of $b$ and light\njets be roughly equal in mass, without assuming the mass value. Thus, ILC can\nprobe low mass Higgs bosons in multijet final states to complement HL-LHC in\nthe future", "category": "hep-ph" }, { "text": "Effects of custodial symmetry breaking in the Georgi-Machacek model at\n high energies: The model proposed by Georgi and Machacek enables the Higgs sector to involve\nisospin triplet scalar fields while retaining a custodial $SU(2)_V$ symmetry in\nthe potential and thus ensuring the electroweak $\\rho$ parameter to be one at\ntree level. This custodial symmetry, however, is explicitly broken by loop\neffects of the $U(1)_Y$ hypercharge gauge interaction. In order to make the\nmodel consistent at high energies, we construct the most general form of the\nHiggs potential without the custodial symmetry, and then we derive the one-loop\n$\\beta$-functions for all the model parameters. Assuming the $\\delta_i$\nquantities describing the custodial symmetry breaking to be zero at low energy,\nwe find that $|\\delta_i|$ are typically smaller than the magnitude of the\n$U(1)_Y$ gauge coupling and the other running parameters in the potential also\nat high energy without spoiling perturbativity and vacuum stability. We also\nclarify that the mass degeneracy among the $SU(2)_V$ 5-plet and 3-plet Higgs\nbosons is smoothly broken by $\\sim 0.1\\%$ corrections. These results show that\nthe amount of the custodial symmetry breaking is well kept under control up to\nenergies close to the theory cutoff.", "category": "hep-ph" }, { "text": "Probing the long-range structure of the $T_{cc}^+$ with the strong and\n electromagnetic decays: Very recently, the LHCb Collaboration reported the doubly charmed tetraquark\nstate $T_{cc}^+$ below the $D^{*+}D^0$ threshold about $273$ keV. As a very\nnear-threshold state, its long-distance structure is very important. In the\nmolecular scheme, we relate the coupling constants of $T_{cc}^+$ with\n$D^{*0}D^+$ and $D^{*+}D^0$ to its binding energy and mixing angle of two\ncomponents with a coupled-channel effective field theory. With the coupling\nconstants, we investigate the kinetically allowed strong decays $T_{cc}^+\\to\nD^0D^0\\pi^+$, $T_{cc}^+\\to D^+D^0\\pi^0$ and radiative decays $D^+D^0 \\gamma$.\nOur results show that the decay width of $T_{cc}^+\\to D^0D^0\\pi^+$ is the\nlargest one, which is just the experimental observation channel. Our\ntheoretical total strong and radiative widths are in favor of the $T_{cc}^+$ as\na $|D^{*+}D^0\\rangle$ dominated bound state. The total strong and radiative\nwidth in the single channel limit and isospin singlet limit are given as\n$59.7^{+4.6}_{-4.4} \\text{ keV}$ and $46.7^{+2.7}_{-2.9} \\text{ keV}$,\nrespectively. Our calculation is cutoff-independent and without prior isospin\nassignment. The absolute partial widths and ratios of the different decay\nchannels can be used to test the structure of $T_{cc}^+$ state when the updated\nexperimental results are available.", "category": "hep-ph" }, { "text": "Effective kinetic description of the expanding overoccupied Glasma: We report on a numerical study of the Boltzmann equation including\n$2\\leftrightarrow 2$ scatterings of gluons and quarks in an overoccupied Glasma\nundergoing longitudinal expansion. We find that when a cascade of gluon number\nto the infrared occurs, corresponding to an infrared enhancement analogous to a\ntransient Bose-Einstein condensate, gluon distributions qualitatively reproduce\nthe results of classical-statistical simulations for the expanding Glasma.\nThese include key features of the distributions that are not anticipated in the\n\"bottom-up\" thermalization scenario. We also find that quark distributions,\nlike those of gluons, satisfy self-similar scaling distributions in the\noveroccupied Glasma. We discuss the implications of these results for a deeper\nunderstanding of the self-similarity and universality of parton distributions\nin the Glasma.", "category": "hep-ph" }, { "text": "Chiral Magnetic Effect in Isobaric Collisions from Anomalous-Viscous\n Fluid Dynamics (AVFD): The isobaric collision experiment at RHIC provides the unique opportunity to\ndetect the possible signal of Chiral Magnetic Effect (CME) in heavy ion\ncollisions. The idea is to contrast the correlation observables of the two\ncolliding systems that supposedly have identical flow-driven background\ncontributions while quite different CME signal contributions due to the 10%\nvariation in their nuclear charge and thus magnetic field strength. With the\nrecently developed quantitative simulation tool for computing CME signal, the\nAnomalous-Viscous Fluid Dynamics (AVFD), we demonstrate that a joint\n(multiplicity + elliptic-flow) event selection is crucial for this purpose. We\nfurther propose to use the absolute difference between RuRu and ZrZr events\n(after using identical event selection) for detecting CME signal and make\npredictions for the correlation observables.", "category": "hep-ph" }, { "text": "Light-Quark, Heavy-Quark Systems: An Update: We review many of the recently developed applications of Heavy Quark\nEffective Theory techniques. After a brief update on Luke's theorem, we\ndescribe striking relations between heavy baryon form factors, and how to use\nthem to estimate the accuracy of the extraction of $|V_{cb}|$. We discuss\nfactorization and compare with experiment. An elementary presentation, with\nsample applications, of reparametrization invariance comes next. The final and\nmost extensive chapter in this review deals with phenomenological lagrangians\nthat incorporate heavy-quark spin-flavor as well as light quark chiral\nsymmetries. We compile many interesting results and discuss the validity of the\ncalculations.", "category": "hep-ph" }, { "text": "Correct $\u0394m^2_{ij}$ Dependence for Neutrino Oscillation Formulae: The time translation operator for neutrino mass states is often taken to be\n$e^{-iEt/\\hbar}$. This is not relativistically invariant. In kaon mixing,\nphysicists use $e^{-imc^2\\tau/\\hbar}$ where $\\tau$ is the proper time of the\nkaon state. The factor $mc^2\\tau$ is the rest frame value of the four vector\nproduct $p_\\mu x^\\mu$ which is an invariant quantity. If $-i p_\\mu x^\\mu$ is\nused in neutrino oscillation formulae instead of $-iEt$, the scale of the\n$\\Delta m^2_{ij}$ is reduced by a factor of two.", "category": "hep-ph" }, { "text": "Large $\\mathbf{b}$ behaviour in the CGC/saturation approach: BFKL\n equation with pion loops: In this paper we proposed a solution to the longstanding problem of the\nCGC/saturation approach: the power-like fall of the scattering amplitudes at\nlarge $b$. This decrease leads to the violation of the Froissart theorem and\nmakes the approach theoretically inconsistent. We showed in the paper that sum\nof the pion loops results in the exponential fall of the scattering amplitude\nat large impact parameters and in the restoration of the Froissart theorem.", "category": "hep-ph" }, { "text": "Probing hyperon CP violation from charmed baryon decays: CP violation (CPV) in the baryon sectors has not yet been established\nexperimentally. In this work, we propose to search for the hyperon CPV through\nthe Cabibbo-favored charm-baryon decaying processes involving a hyperon in the\nfinal states, such as $\\Lambda_c^+\\to \\Lambda^0\\pi^+, \\Lambda^0\\to p\\pi^-$. The\nCPV of the hyperon decays are purely revealed in these chain processes, since\nthe CPV in the Cabibbo-favored charm decays are vanishing in the Standard Model\n(SM). The hyperons are polarized in the weak charm decays, so that we can\nmeasure the Lee-Yang asymmetric parameter $\\alpha$ by the angular\ndistributions, and then can measure the $\\alpha$-induced CPV. It can be found\nthat it is accessible for Belle II and LHCb to reach the SM prediction of the\nhyperon CPV in the near future.", "category": "hep-ph" }, { "text": "Photoproduction of the charged charmoniumlike $Z_{c}^{+}(4200)$: In this work, inspired by the observation of charmoniumlike\n$Z_{c}^{+}(4200)$% , we study the photoproduction of charged charmoniumlike\n$Z_{c}^{+}(4200)$ with an effective Lagrangian approach and the Regge\ntrajectories model. The numerical results indicate that the Reggeized treatment\ncan lead to a lower total cross section of the $Z_{c}^{+}(4200)$\nphotoproduction and the peak position of cross section was moved to the higher\nenergy point when the Reggeized treatment was added. {Moreover, using the data\nfrom the COMPASS experiment and presented theoretical predictions, an upper\nlimit of the decay width of $Z_{c}(4200)\\rightarrow J/\\psi \\pi $ is estimated.}\nThe relevant results not only shed light on the further experiment of searching\nfor the charmoniumlike $Z_{c}(4200)$ state via meson photoproduction, but also\nprovide valuable informations for having a better comprehension of the nature\nof charmoniumlike $Z_{c}(4200)$ state.", "category": "hep-ph" }, { "text": "SMEFT analysis of vector boson scattering and diboson data from the LHC\n Run II: We present a systematic interpretation of vector boson scattering (VBS) and\ndiboson measurements from the LHC in the framework of the dimension-six\nStandard Model Effective Field Theory (SMEFT). We consider all available\nmeasurements of VBS fiducial cross-sections and differential distributions from\nATLAS and CMS, in most cases based on the full Run II luminosity, and use them\nto constrain 16 independent directions in the dimension-six EFT parameter\nspace. Compared to the diboson measurements, we find that VBS provides\ncomplementary information on several of the operators relevant for the\ndescription of the electroweak sector. We also quantify the ultimate EFT reach\nof VBS measurements via dedicated projections for the High Luminosity LHC. Our\nresults motivate the integration of VBS processes in future global SMEFT\ninterpretations of particle physics data.", "category": "hep-ph" }, { "text": "Color confinement from fluctuating topology: QCD possesses a compact gauge group, and this implies a non-trivial\ntopological structure of the vacuum. In this contribution to the Gribov-85\nMemorial volume, we first discuss the origin of Gribov copies and their\ninterpretation in terms of fluctuating topology in the QCD vacuum. We then\ndescribe the recent work with E. Levin that links the confinement of gluons and\ncolor screening to the fluctuating topology, and discuss implications for spin\nphysics, high energy scattering, and the physics of quark-gluon plasma.", "category": "hep-ph" }, { "text": "Proposal and theoretical formalism for studying baryon radiative decays\n from J/\u03c8\\to B^*\\bar B + \\bar{B^*}B \\to \u03b3B\\bar B: With accumulation of high statistics data at BESIII, one may study many new\ninteresting channels. Among them, J/\\psi \\to B^*\\bar B + \\bar{B^*}B \\to \\gamma\nB\\bar B processes may provide valuable information of the radiative decays of\nthe excited baryons (N^*,\\Lambda^*,\\Sigma^*,\\Xi^*), and may shed light on their\ninternal quark-gluon structure. Our estimation for the branching ratios of the\nnucleon excitations N^*(1440), N^*(1535) and N^*(1520) from the reaction J/\\psi\n\\to N^*\\bar p + \\bar N^* p \\to \\gamma p\\bar p, indicates that these processes\ncan be studied at BESIII with 10^{10} J/\\psi events. Explicit theoretical\nformulae for the partial wave analysis (PWA) of the J/\\psi \\to B^*\\bar B +\\bar\nB^* B with B^*\\to B \\gamma and \\bar B^*\\to \\bar B\\gamma within covariant L-S\nScheme are provided.", "category": "hep-ph" }, { "text": "Technicolor Enhancement of $t \\bar{t}$ Production at TeV-Colliders: It is shown that a technicolor theory containing a color-octet technipion,\nusually denoted by $P^{0'}_{8}$, will give rise to an enhancement of $t \\bar t$\nproduction at the Tevatron, LHC and SSC, via the process $gg \\rightarrow\nP^{0'}_{8} \\rightarrow t \\bar t$. The relevant cross-sections are computed\ntaking into account the large lower bound on the top mass coming from the \"top\nsearch\" experiments at LEP and CDF.\n At the LHC and SSC, the signal is found to be comparable to the QCD\nbackground, making the process quite accesible.", "category": "hep-ph" }, { "text": "Concerning pion parton distributions: Analyses of the pion valence-quark distribution function (DF),\n${u}^\\pi(x;\\zeta)$, which explicitly incorporate the behaviour of the pion wave\nfunction prescribed by quantum chromodynamics (QCD), predict ${u}^\\pi(x\\simeq\n1;\\zeta) \\sim (1-x)^{\\beta(\\zeta)}$, $\\beta(\\zeta \\gtrsim m_p)>2$, where $m_p$\nis the proton mass. Nevertheless, more than forty years after the first\nexperiment to collect data suitable for extracting the $x\\simeq 1$ behaviour of\n${u}^\\pi$, the empirical status remains uncertain because some methods used to\nfit existing data return a result for ${u}^\\pi$ that violates this constraint.\nSuch disagreement entails one of the following conclusions: the analysis\nconcerned is incomplete; not all data being considered are a true expression of\nqualities intrinsic to the pion; or QCD, as it is currently understood, is not\nthe theory of strong interactions. New, precise data are necessary before a\nfinal conclusion is possible. In developing these positions, we exploit a\nsingle proposition, viz. there is an effective charge which defines an\nevolution scheme for parton DFs that is all-orders exact. This proposition has\nnumerous corollaries, which can be used to test the character of any DF,\nwhether fitted or calculated.", "category": "hep-ph" }, { "text": "Quark sector of S3 models: classification and comparison with\n experimental data: S3 models offer a low energy approach to describe the observed pattern of\nmasses and mixing, of both quarks and leptons. In this work, we first revisit\nan S3 model with only one Higgs electroweak doublet, where the flavour symmetry\nmust be broken in order to produce an acceptable pattern of masses and mixing\nfor fermions. Then, we analyse different S3 models, where the flavour symmetry\nis preserved as an exact, but hidden symmetry of the low energy spectra, after\nthe electroweak symmetry breaking. The latter models require the addition of\ntwo more Higgs electroweak doublets which are accommodated in an S3 doublet. We\nalso explore the consequences of adding a fourth Higgs electroweak doublet,\nthus occupying all three irreducible representations of S3. We show how the\nvarious S3-invariant mass matrices of the different models can reproduce the\ntwo texture zeroes and Nearest Neighbour Interaction matrix forms, which have\nbeen found to provide a viable and universal treatment of mixing for both\nquarks and leptons. We also find analytical and exact expressions for the CKM\nmatrix of the models in terms of quark mass ratios. Finally, we compare the\nexpressions of the CKM matrix of the different S3 models with the most up to\ndate values of masses and mixing in the quark sector, via a chi^2 analysis. We\nfind that the analytical expressions we derived reproduce remarkably well the\nmost recent experimental data of the CKM matrix, suggesting that S3 is a\nsymmetry of the quark sector.", "category": "hep-ph" }, { "text": "Axial Vector $cc$ and $bb$ Diquark Masses from QCD Laplace Sum-Rules: Constituent mass predictions for axial vector (i.e., $J^P=1^+$) $cc$ and $bb$\ncolour antitriplet diquarks are generated using QCD Laplace sum-rules. We\ncalculate the diquark correlator within the operator product expansion to NLO,\nincluding terms proportional to the four- and six-dimensional gluon and\nsix-dimensional quark condensates. The sum-rules analyses stabilize, and we\nfind that the mass of the $cc$ diquark is 3.51~GeV and the mass of the $bb$\ndiquark is 8.67~GeV. Using these diquark masses as inputs, we calculate several\ntetraquark masses within the Type-II diquark-antidiquark tetraquark model.", "category": "hep-ph" }, { "text": "Reduction of the proton radius discrepancy by 3 sigma: We show that in previous analyses of electron-proton scattering, the\nuncertainties in the statistical procedure to extract the proton charge radius\nare underestimated. Using a fit function based on a conformal mapping, we can\ndescribe the scattering data with high precision and extract a radius value in\nagreement with the one obtained from muonic hydrogen.", "category": "hep-ph" }, { "text": "Nuclear Force from Monte Carlo Simulations of Lattice Quantum\n Chromodynamics: The nuclear force acting between protons and neutrons is studied in the Monte\nCarlo simulations of the fundamental theory of the strong interaction, the\nquantum chromodynamics defined on the hypercubic space-time lattice. After a\nbrief summary of the empirical nucleon-nucleon (NN) potentials which can fit\nthe NN scattering experiments in high precision, we outline the basic\nformulation to derive the potential between the extended objects such as the\nnucleons composed of quarks. The equal-time Bethe-Salpeter amplitude is a key\ningredient for defining the NN potential on the lattice. We show the results of\nthe numerical simulations on a $32^4$ lattice with the lattice spacing $a\n\\simeq 0.137 $fm (lattice volume (4.4 fm)$^4$) in the quenched approximation.\nThe calculation was carried out using the massively parallel computer Blue\nGene/L at KEK. We found that the calculated NN potential at low energy has\nbasic features expected from the empirical NN potentials; attraction at long\nand medium distances and the repulsive core at short distance. Various future\ndirections along this line of research are also summarized.", "category": "hep-ph" }, { "text": "Single Spin Asymmetry in Inclusive Pion Production, Collins Effect and\n the String Model (revised version): We calculated the single spin asymmetry in the inclusive pion production in\nthe fragmentation region of transversely polarized proton-proton collisions. We\ngenerated the asymmetry at the level of fragmentation function (Collins effect)\nby the Lund coloured string mechanism. We compared our results to the presently\navailable experimental data. We obtained a qualitative agreement with the data\nafter assuming that the transverse polarizations of the $u$ and the $d$ quarks\nin the proton are +1 and -1, respectively, at x_B = 1.", "category": "hep-ph" }, { "text": "Can the X(3872) be a 1^{++} four-quark state?: We use QCD spectral sum rules to test the nature of the meson X(3872),\nassumed to be an exotic four-quark (c\\bar{c}q\\bar{q}) state with J^{PC}=1^{++}.\nFor definiteness, we work with the current proposed recently by Maiani et al\n[1], at leading order in \\alpha_s, consider the contributions of higher\ndimension condensates and keep terms which are linear in the light quark mass\nm_q. We find M_X=(3925+- 127) MeV which is compatible, within the errors, with\nhe experimental candidate X(3872), while the SU(3) breaking-terms lead to an\nunusual mass-splitting M_{X^{s}}-M_X=- (61+-30) MeV. The mass-difference\nbetween the neutral states due to isospin violation of about (2.6-3.9) MeV is\nmuch smaller than the value (8+-3) MeV proposed in [1]. For the b-quark, we\npredict M_{X_b}= (10144+-106) MeV for the X_b(b\\bar{b}q \\bar{q}), which is much\nbelow the {\\bar B}B* threshold in contrast to the {\\bar B}B* molecule\nprediction [2], and for the X_b^s(b\\bar{b}s \\bar{s}), a mass-splitting\nM_{X^s_{b}}-M_{X_b}=-(121+-182) MeV. Our analysis also indicates that the\nmass-splitting between the ground state and the radial excitation of about\n(225~250) MeV is much smaller than in the case of ordinary mesons and is\n(within the errors) flavour-independent. We also extract the decay constants,\nanalogous to f_\\pi, of such mesons, which are useful for further studies of\ntheir leptonic and hadronic decay widths. The uncertainties of our estimates\nare mainly due to the ones from the c and b quark masses.", "category": "hep-ph" }, { "text": "First Lattice QCD Study of the Sigma -> n Axial and Vector Form Factors\n with SU(3) Breaking Corrections: We present the first quenched lattice QCD study of the form factors relevant\nfor the hyperon semileptonic decay Sigma -> n l nu. The momentum dependence of\nboth axial and vector form factors is investigated and the values of all the\nform factors at zero-momentum transfer are presented. Following the same\nstrategy already applied to the decay K0 -> pi- l nu, the SU(3)-breaking\ncorrections to the vector form factor at zero-momentum transfer, f1(0), are\ndetermined with great statistical accuracy in the regime of the simulated quark\nmasses, which correspond to pion masses above ~ 0.7 GeV. Besides f1(0) also the\naxial to vector ratio g1(0) / f1(0), which is relevant for the extraction of\nthe CKM matrix element Vus, is determined with significant accuracy. Due to the\nheavy masses involved, a polynomial extrapolation, which does not include the\neffects of meson loops, is performed down to the physical quark masses,\nobtaining f1(0) = -0.948 +/- 0.029 and g1(0) / f1(0) = -0.287 +/- 0.052, where\nthe uncertainties do not include the quenching effect. Adding a recent\nnext-to-leading order determination of chiral loops, calculated within the\nHeavy Baryon Chiral Perturbation Theory in the approximation of neglecting the\ndecuplet contribution, we obtain f1(0) = -0.988 +/- 0.029(lattice) +/-\n0.040(HBChPT). Our findings indicate that SU(3)-breaking corrections are\nmoderate on both f1(0) and g1(0). They also favor the experimental scenario in\nwhich the weak electricity form factor, g2(0), is large and positive, and\ncorrespondingly the value of |g1(0) / f1(0)| is reduced with respect to the one\nobtained with the conventional assumption g2(q**2) = 0 based on exact SU(3)\nsymmetry.", "category": "hep-ph" }, { "text": "Eta-eta' mixing from V->Pgamma and J/psi->VP decays: The $\\eta$-$\\eta^\\prime$ pseudoscalar mixing angle and the gluonium content\nof the $\\eta^\\prime$ meson are deduced from an updated phenomenological\nanalysis of $V\\to P\\gamma$ and $J/\\psi\\to VP$ decays. In absence of gluonium,\nthe value of the mixing angle in the quark-flavour basis is found to be\n$\\phi_P=(41.5\\pm 1.2)^\\circ$ from $V\\to P\\gamma$ and $\\phi_P=(40.5\\pm\n2.4)^\\circ$ from $J/\\psi\\to VP$. In presence of gluonium, the values for the\nmixing angle and the gluonic content of the $\\eta^\\prime$ wave function are\n$\\phi_P=(41.4\\pm 1.3)^\\circ$ and $Z^2_{\\eta^\\prime}=0.04\\pm 0.09$ from $V\\to\nP\\gamma$ and $\\phi_P=(44.5\\pm 4.3)^\\circ$ and $Z^2_{\\eta^\\prime}=0.28\\pm 0.21$\nfrom $J/\\psi\\to VP$, respectively.", "category": "hep-ph" }, { "text": "Neutrino Mass from Triplet and Doublet Scalars at the TeV Scale: If the minimal standard model of particle interactions is extended to include\na scalar triplet with lepton number $L=-2$ and a scalar doublet with $L=-1$,\nneutrino masses $m_\\nu \\sim \\mu_{12}^4 v^2/M^5 \\sim 10^{-2}$ eV is possible,\nwhere $v \\sim 10^2$ GeV is the electroweak symmetry breaking scale, $M \\sim 1$\nTeV is the typical mass of the new scalars, and $\\mu_{12} \\sim 1$ GeV is a soft\nlepton-number-violating parameter.", "category": "hep-ph" }, { "text": "QCD Corrections to Flavor Changing Neutral Coupling Mediated Rare Top\n Quark Decays: Recently we have presented an analysis of flavor changing neutral coupling\nmediated radiative top quark decays at next-to-leading order in QCD. In the\npresent paper we provide the details of the calculation of QCD corrections to\nt-> q gamma and t-> q Z decays within the effective theory approach including\noperator mixing. In particular, we calculate virtual matrix element corrections\nand the corresponding bremsstrahlung contributions. In the case of t-> q gamma\nwe study the effects of kinematic cuts on the extracted branching ratios.\nAnalytical formulae are given at all stages of the calculation. We find that\nthe t-> q gamma decay can be used to probe also the effective operators\nmediating t-> q g processes, since these can naturally contribute 10% or more\nto the radiative decay, given typical experimental cuts on the decay kinematics\nat hadron colliders. Conversely, we argue that any positive experimental signal\nof the t-> q g process would indicate a natural lower bound on t-> q gamma\ndecay rate.", "category": "hep-ph" }, { "text": "Learning to Identify Semi-Visible Jets: We train a network to identify jets with fractional dark decay (semi-visible\njets) using the pattern of their low-level jet constituents, and explore the\nnature of the information used by the network by mapping it to a space of jet\nsubstructure observables. Semi-visible jets arise from dark matter particles\nwhich decay into a mixture of dark sector (invisible) and Standard Model\n(visible) particles. Such objects are challenging to identify due to the\ncomplex nature of jets and the alignment of the momentum imbalance from the\ndark particles with the jet axis, but such jets do not yet benefit from the\nconstruction of dedicated theoretically-motivated jet substructure observables.\nA deep network operating on jet constituents is used as a probe of the\navailable information and indicates that classification power not captured by\ncurrent high-level observables arises primarily from low-$p_\\textrm{T}$ jet\nconstituents.", "category": "hep-ph" }, { "text": "An alternative heavy Higgs mass limit: After commenting on the present value of the Higgs particle mass from\nradiative corrections, we explore the phenomenological implications of an\nalternative, non-perturbative renormalization of the scalar sector where the\nmass of the Higgs particle does not represent a measure of observable\ninteractions at the Higgs mass scale. In this approach the Higgs particle could\nbe very heavy, even heavier than 1 TeV, and remain nevertheless a relatively\nnarrow resonance.", "category": "hep-ph" }, { "text": "Two-particle Correlations in multi-Regge Kinematics: Multi-jet production at the LHC is an important process to study. In\nparticular, events with final state kinematic configurations where we have two\njets widely separated in rapidity with similar pT and lots of mini-jets or jets\npopulating the space in between are relevant for the high energy limit of QCD.\nKeeping the jet multiplicity fixed, the study of these events is a good ground\nto test different models of multi-particle production in hadron-hadron\ncollisions. We report on a comparison between the predictions of the old\nmultiperipheral Chew-Pignotti model and those of BFKL for the single jet\nrapidity distributions and for jet-jet rapidity correlations.", "category": "hep-ph" }, { "text": "BFKL Pomeron and the survival factor: We consider the absorptive corrections and the rapidity gap survival factor\nwhich are necessary to provide the unitarization of the BFKL Pomeron. In\nparticular we discuss the role of the enhanced screening diagrams.", "category": "hep-ph" }, { "text": "Lecture notes on the Skyrme model: This lecture provides a pedagogical instruction to the basic concepts of the\nSkyrme model and its some applications. As the preliminary for understanding\nthe Skyrme model, we first briefly explain the large $N_c$ expansion, chiral\nsymmetry and its breaking. Next we give a brief review of nonlinear sigma model\nincluding the power counting scheme of the chiral perturbation theory, starting\nfrom the linear sigma model. We then give an exhaust explanation of the Skyrme\nmodel and its applications. After the presentation of the Skyrme model for\nbaryons in free space, we introduce how to study the baryonic matter and medium\nmodified hadron properties by using the Skyrme model. Finally we discuss a way\nto incorporate the lowest-lying vector mesons into the Skyrme model based on\nthe hidden local symmetry. Some possible further developments are also covered.", "category": "hep-ph" }, { "text": "Top Quark Physics: In this contribution I review the physics of top quarks at a future Linear\nCollider. Main emphasis is put on the process e+ e- to ttbar close to\nthreshold. Different physical observables, their sensitivity to the basic\nparameters and their theoretical prediction are discussed. Recent higher order\ncalculations are shown to have a considerable impact on a precise determination\nof the top quark mass. It is pointed out how the use of mass definitions\ndifferent from the pole mass scheme become important in this respect. Continuum\ntop quark production above threshold is discussed briefly.", "category": "hep-ph" }, { "text": "A Higgslike Dilaton: We examine the possibility that the recently discovered 125 GeV higgs like\nresonance actually corresponds to a dilaton: the Goldstone boson of scale\ninvariance spontaneously broken at a scale f. Comparing to LHC data we find\nthat a dilaton can reproduce the observed couplings of the new resonance as\nlong as f ~ v, the weak scale. This corresponds to the dynamical assumption\nthat only operators charged under the electroweak gauge group obtain VEVs. The\nmore difficult task is to keep the mass of the dilaton light compared to the\ndynamical scale, Lambda ~ 4 pi f, of the theory. In generic, non-supersymmetric\ntheories one would expect the dilaton mass to be similar to Lambda. The mass of\nthe dilaton can only be lowered at the price of some percent level (or worse)\ntuning and/or additional dynamical assumptions: one needs to suppress the\ncontribution of the condensate to the vacuum energy (which would lead to a\nlarge dilaton quartic coupling), and to allow only almost marginal deformations\nof the CFT.", "category": "hep-ph" }, { "text": "New-Physics Search in gamma gamma --> t tbar: We performed an analysis on possible anomalous top-quark couplings generated\nby SU(2) x U(1) gauge-invariant dimension-6 effective operators, applying the\noptimal-observable procedure to the final lepton/b-quark momentum distribution\nin gamma gamma --> t tbar --> l X/b X. We studied how many such anomalous\ncoupling constants could be determined altogether through these distributions.", "category": "hep-ph" }, { "text": "Revealing the source of the radial flow patterns in proton--proton\n collisions using hard probes: In this work, we propose a tool to reveal the origin of the collective-like\nphenomena observed in proton--proton collisions. We exploit the fundamental\ndifference between the underlying mechanisms, color reconnection (CR) and\nhydrodynamics, which produce radial flow patterns in \\textsc{Pythia}~8 and\n\\textsc{Epos}~3, respectively. Specifically, we proceed by examining the\nstrength of the coupling between the soft and hard components which, by\nconstruction, is larger in \\textsc{Pythia}~8 than in \\textsc{Epos}~3. We study\nthe transverse momentum ($p_{\\rm T}$) distributions of charged pions, kaons and\n(anti)protons in inelastic pp collisions at $\\sqrt{s}=$ 7\\,TeV produced at\nmid-rapidity. Specific selections are made on an event-by-event basis as a\nfunction of the charged particle multiplicity and the transverse momentum of\nthe leading jet ($p_{\\rm T}^{\\rm jet}$) reconstructed using the\n\\textsc{FastJet} algorithm at mid-pseudorapidity ($|\\eta|<1$). From our\nstudies, quantitative and qualitative differences between \\textsc{Pythia}~8 and\n\\textsc{Epos}~3 are found in the $p_{\\rm T}$ spectra when (for a given\nmultiplicity class) the leading jet $p_{\\rm T}$ is increased. In addition, we\nshow that for low-multiplicity events the presence of jets can produce radial\nflow-like behavior. Motivated by our findings, we propose to perform a similar\nanalysis using experimental data from RHIC and LHC.", "category": "hep-ph" }, { "text": "Real time simulations of high energy nuclear collisions: We discuss real time simulations of high energy nuclear collisions in a\nclassical effective theory of QCD at small x. At high transverse momenta, our\nresults match the lowest order predictions of pQCD based mini-jet calculations.\nWe discuss novel non-perturbative behaviour of the small x modes seen at small\ntransverse momenta.", "category": "hep-ph" }, { "text": "Implementation of target mass corrections and higher-twist effects in\n the xFitter framework: Knowledge of parton distribution functions (PDFs) at large momentum fraction\n$ x $ is not only important to study the flavor and spin dynamics of quarks in\nthe nucleon, but also to search for signals of new physics at collider\nexperiments. It is well known now that the nonperturbative QCD effects\ngenerally play a more significant role at such kinematic regions. In this work,\nwe present an open-source QCD analysis of PDFs considering target mass\ncorrections (TMCs) and higher-twist (HT) effects which are necessary when the\nanalysis includes also data points from deep inelastic scattering (DIS) with\nlarger values of $ x $ and smaller values of photon virtuality $ Q^2 $. To this\naim, we use the xFitter package, as a comprehensive and powerful tool for\nstudying PDFs. We report and discuss our recent activities on the\nimplementation of TMCs and HT effects in the xFitter framework in a\nuser-friendly way, so that the user can switch on or off them, and also choose\nbetween different options. We check the validity of the modifications by\nperforming sample analyses of PDFs considering TMCs and HT effects and using a\nwide range of DIS data.", "category": "hep-ph" }, { "text": "Mass of the Stabilized Radion in the Limit of Finite Quartic Coupling: We present an exact treatment of the modulus stabilization condition with the\ngeneral boundary conditions of the bulk scalar field in the Randall-Sundrum\nmodel. We find analytical expressions for the value of the modulus and the mass\nof the radion.", "category": "hep-ph" }, { "text": "Hard colour singlet exchange at the Tevatron from the BFKL equation: We study rapidity gaps between jets in ppbar collisions at the Tevatron by a\nnovel solution of the nonforward BFKL equation including nonleading effects\nthrough the consistency constraint and running coupling. Results differ from\nearlier calculations based on the asymptotic Mueller-Tang formula, but agree\nwith D0 data when including full event simulation using PYTHIA to model the gap\nsurvival probability.", "category": "hep-ph" }, { "text": "Non-linear corrections to the longitudinal structure function $F_{L}$\n from the parametrization of $F_{2}$: Laplace transform approach: The non-linear corrections (NLC) to the longitudinal structure function in a\nlimited approach is derived at low values of the Bjorken variable $x$ by using\nthe Laplace transforms technique. The non-linear behavior of the longitudinal\nstructure function is determined with respect to the Gribov-Levin-Ryskin\nMueller-Qiu (GLR-MQ) and Altarelli-Martinelli (AM) equations. These results\nshow that the non-linear longitudinal structure function can be determined\ndirectly in terms of the parametrization of $F_{2}(x,Q^{2})$ and the derivative\nof the proton structure function with respect to $\\ln{Q^{2}}$. These\ncorrections improve the behavior of the longitudinal structure function at low\nvalues of $Q^{2}$ in comparison with other parametrization methods.", "category": "hep-ph" }, { "text": "D_{sJ}^+(2317)\\to D_s^+\u03c0^0 decay width: We use the QCD sum rules to analize the hadronic decay $D_{sJ}^{+}(2317)\\to\nD_s^+\\pi^0$, in the hypotesis that the $D_{sJ}^{+}(2317)$ can be identified as\na four-quark state. We use a diquak-antidiquark current and work to the order\nof $m_s$ in full QCD, without relying on $1/m_c$ expansion. We find that the\npartial decay width of the hadronic isospin violating mode is proportional to\nthe isovector quark condensate, $\\langle0|\\bar{d}d-\\bar{u}u|0\\rangle$. The\nestimated partial decay width is of the order of 6 keV.", "category": "hep-ph" }, { "text": "Non-Unitary $3 \\times 3$ Mixing in Majorana Neutrinos and Vector-like\n Quark Models: Non-unitary $3 \\times 3$ mixing matrices are present in many extensions of\nthe Standard Model. One of the most simple extensions is the addition of $n_R$\nright-handed neutrinos without imposing Lepton Number Conservation\n($n_R$$\\nu$SM). In the region of the parameter space where the usual seesaw\napproximation is valid, deviations from $3 \\times 3$ unitarity of the leptonic\nmixing matrix are negligible, while one has three light neutrinos and two or\nthree heavy neutrinos with masses close to the GUT scale. This gap between the\nmass scales occurs while having order 1 Yukawa couplings, providing a natural\nexplanation for the smallness of light neutrino masses - hence the name seesaw.\nOther regions of the parameter space, with lighter heavy neutrinos - with an eV\nor keV mass, for instance - and bigger deviations from unitarity of the\nleptonic mixing matrix, are still allowed by experiment. In fact, whenever\nheavy neutrino masses are many orders of magnitude below the GUT scale there\nare interesting phenomenological implications at low energies. To analyse such\nregions with precision, one needs an exact parameterisation, since\napproximations that were valid in the usual seesaw case now fail. This thesis\nwill consist of a study and classification of regions of the 3$\\nu$SM parameter\nspace in the light of a newly-developed exact parameterisation. Furthermore, it\nwill also include a study of models with vector-like quarks, another simple\nextension of the SM, that contains a $3 \\times 3$ non-unitary quark mixing\nmatrix. Studying the most interesting regions of the parameter space of\nvector-like quarks models also benefits from the use of the aforementioned\nexact parameterisation. These regions are phenomenologically rich and may\nexplain certain open questions like the CKM unitarity problem/Cabibbo angle\nanomaly. A chapter discussing the experimental implications of these models is\nalso included.", "category": "hep-ph" }, { "text": "Indirect Searches for $Z'$-like Resonances at the LHC: We explore the possibility of indirectly observing the effects of $Z'$-like\nparticles with electroweak strength couplings in the Drell-Yan channel at the\nLHC with masses above the resonance direct search reach. We find that, mostly\ndue to statistical limitations, this is very unlikely in almost all classes of\nmodels independently of the spin of the resonance. Not unexpectedly, the one\npossible exception to this general result is the case of degenerate\nKaluza-Klein (KK) excitations of the photon and $Z$ that occur in some\nextra-dimensional models. In this special case, the strong destructive\ninterference with the Standard Model (SM) exchanges below the resonance mass\nleads to a well-known significant suppression of the cross section and thus\nincreased sensitivity to this particular new physics scenario.", "category": "hep-ph" }, { "text": "Higgs inflation and Higgs portal dark matter with right-handed neutrinos: We investigate the Higgs inflation and the Higgs portal dark matter with the\nright-handed neutrino. The dark matter and the right-handed neutrino in the\nHiggs inflation play important roles in explaining the recent experimental\nresults of the Higgs and top masses, and the cosmic microwave background by\nBICEP2 at the same time. This inflation model predicts $805~{\\rm GeV} \\lesssim\nm_{\\rm DM} \\lesssim1220~{\\rm GeV}$ for the DM mass, $1.05 \\times10^{14}~{\\rm\nGeV} \\lesssim M_R \\lesssim 2.04 \\times10^{14}~{\\rm GeV}$ for the right-handed\nneutrino mass, and $8.42 \\lesssim \\xi \\lesssim 12.4$ for the non-minimal\ncoupling within $m_H=125.6 \\pm 0.35~{\\rm GeV}$ for the Higgs and $M_t=173.34\n\\pm 0.76~{\\rm GeV}$ for the top masses.", "category": "hep-ph" }, { "text": "Reducing the Quadratic Divergence in the Higgs Mass Squared Without Top\n Partners: We examine a model with multiple scalar fields to see whether it is possible\nto reduce the fine- tuning of the SM Higgs mass without introducing low scale\ntop partners. Our approach may be regarded as a generalization of the condition\nproposed by Veltman, who attempted to predict the Higgs mass using the\ncriterion that the various low energy contributions to the quadratic divergence\nof the Higgs mass cancel. Although the Veltman condition predicts the wrong\nHiggs mass in the Standard Model, it can still be adapted to extended Higgs\nsectors. Furthermore, theories with additional Higgs bosons can lead to\nsuppressed Yukawa couplings of the top quark to the 125 GeV Higgs, making the\nassociated one-loop divergence smaller. Here, we review possible extensions of\nthe Standard Model where the Veltman condition could be realized, and study in\ndetail one minimal model with two extra scalar fields. For this model and for a\ncutoff of 5 TeV, we show that the overall fine-tuning can be considerably\nlowered without introducing low-scale Landau poles, albeit the Higgs sector\nwill be strongly coupled at the cutoff. Models where the top Yukawa coupling is\nreduced, in particular, will be within the reach of the upcoming LHC searches.", "category": "hep-ph" }, { "text": "Errata for \"The Higgs Hunter's Guide\": Errata are given for \"The Higgs Hunter's Guide\". These errata should be\napplied to the second printing of the book, dated 1991. The second printing has\nalready corrected numerous errors and misprints contained in the originally\npublished 1990 edition.", "category": "hep-ph" }, { "text": "Soft scalar masses in supergravity with horizontal U(1)_X gauge symmetry: In supergravity with modular invariance and horizontal $U(1)_X$ gauge\nsymmetry there is a relation between modular weights and $U(1)_X$ charges. The\nsoft scalar masses are then strongly correlated with Yukawa matrices. The\nimplications for FCNC are discussed.", "category": "hep-ph" }, { "text": "Top quark pair production at small transverse momentum in hadronic\n collisions: We investigate the transverse momentum resummation for top quark pair\nproduction at hadron colliders using the soft-collinear effective theory and\nthe heavy-quark effective theory. We derive the factorization formula for\n$t\\bar{t}$ production at small pair transverse momentum, and show in detail the\nprocedure for calculating the key ingredient of the factorization formula: the\nnext-to-leading order soft functions. We compare our numerical results with\nexperimental data and find that they are consistent within theoretical and\nexperimental uncertainties. To verify the correctness of our resummation\nformula, we expand it to the next-to-leading order and the\nnext-to-next-to-leading order, and compare those expressions with the exact\nfixed-order results numerically. Finally, using the results of transverse\nmomentum resummation, we discuss the transverse-momentum-dependent\nforward-backward asymmetry at the Tevatron.", "category": "hep-ph" }, { "text": "Models of Flavor with Discrete Symmetries: In an attempt to understand the observed patterns of lepton and quark masses,\nmodels invoking a flavor symmetry $G_f$, under which the Standard Model\ngenerations are charged, have been proposed. One particularly successful\nsymmetry, U(2), has been extensively discussed in the literature. The Yukawa\nmatrices in models based on this symmetry reproduce the observed mass ratios in\nthe lepton and quark sectors. The features of the symmetry that determine the\ntexture of the Yukawa matrices can be found in other symmetries as well. We\npresent a model based on a minimal, non-Abelian discrete symmetry that\nreproduces the Yukawa matrices associated with U(2) theories of flavor. In\naddition to reproducing the mass and mixing angle relations obtained in such\ntheories, the different representation structure of our new horizontal symmetry\nallows for solutions to the solar and atmospheric neutrino problems.", "category": "hep-ph" }, { "text": "Squark production with R-symmetry beyond NLO at the LHC: The Minimal R-symmetric Supersymmetric Standard Model (MRSSM) provides a\nrealisation of supersymmetry in which the parameter space is less constrained\nby the current LHC data than in the simplest supersymmetric scenarios. In the\npresent paper, we obtain the most precise theoretical predictions in the MRSSM\nfor squark production at the LHC, enabling accurate interpretations of LHC data\nin terms of the MRSSM. We perform threshold resummation of soft gluon\ncorrections to the total cross sections for the production of\nsquark-(anti)squark pairs at the LHC in the MRSSM framework. The resummation is\ncarried out using the direct QCD method and reaches the\nnext-to-next-to-leading-logarithmic (NNLL) accuracy, which requires calculating\nthe one-loop matching coefficients in the relevant production channels. The\nresummed cross sections are then matched to the available NLO results and\nevaluated for $\\sqrt{S}=13.6$ TeV. Compared with the Minimal Supersymmetric\nStandard Model (MSSM), the cross sections in the MRSSM can be significantly\nreduced, implying less stringent limits on squark and gluino masses. Our\nresults carry significant implications for exploring the viability of\nsupersymmetry at the LHC. The results of our calculation are publicly available\nas a numerical package.", "category": "hep-ph" }, { "text": "Large Top Mass and Non-Linear Representation of Flavour Symmetry: We consider an effective theory (ET) approach to flavour-violating processes\nbeyond the Standard Model (SM), where the breaking of flavour symmetry is\ndescribed by spurion fields whose low-energy vacuum expectation values are\nidentified with the SM Yukawa couplings. Insisting on canonical mass dimensions\nfor the spurion fields, the large top-quark Yukawa coupling also implies a\nlarge expectation value for the associated spurion, which breaks part of the\nflavour symmetry already at the UV scale Lambda of the ET. Below that scale,\nflavour symmetry in the ET is represented in a non-linear way by introducing\nGoldstone modes for the partly broken flavour symmetry and spurion fields\ntransforming under the residual symmetry. As a result, the dominance of certain\nflavour structures in rare quark decays can be understood in terms of the\n1/Lambda expansion in the ET. We also discuss the generalization to\n2-Higgs-doublet models with large tan(beta).", "category": "hep-ph" }, { "text": "Refined renormalization group improvement for thermally resummed\n effective potential: We newly develop a renormalization group (RG) improvement for thermally\nresummed effective potentials. In this method, $\\beta$-functions are\nconsistently defined in resummed perturbation theories, so that order-by-order\nRG invariance is not spoiled after thermal resummation. With this improvement,\nscale dependences of phase transition quantities such as a critical\ntemperature, which are known to be notoriously large at the one-loop order, are\ngreatly reduced compared to calculations with the conventional\n$\\overline{\\text{MS}}$ scheme. By taking advantage of the RG invariance, we\nalso devise a resummation method that can incorporate potentially harmful large\nlogarithmic terms and temperature-dependent power corrections in a generic\nform. We point out that a resummed one-loop effective potential refined by the\nmethod can give results that agree with those obtained by resummed two-loop\neffective potentials within errors.", "category": "hep-ph" }, { "text": "Dashen's theorem and electromagnetic masses of the mesons: Employing $U(3)_L\\times U(3)_R$ chiral field theory, we find that Dashen's\ntheorem, which holds for pseudoscalar mesons, can be generalized to the sector\nof axial-vector mesons, however, fails for vector mesons.", "category": "hep-ph" }, { "text": "Mixing dynamics of dimension-five interactions\n (scalar/pseudoscalar-photon) in magnetized medium: In many extentions of standard model, dimension-5 scalar di-photon\n($g_{\\gamma\\gamma\\phi}\\phi$ $F^{\\mu\\nu}F_{\\mu\\nu}$ ) or pseudoscalar di-photon\n($g_{\\gamma\\gamma a}a\\tilde{F}^{\\mu\\nu} F_{\\mu\\nu} $, ) interaction\nmaterializes due to scale symmetry breaking or $U_A(1)$ symmetry breaking. In a\nmagnetized vacuum (i.e., in an external background field $\\bar{F}_{\\mu\\nu} $)\nthe transverse degrees of freedom of the photons-- for such systems-- can be\ndescribed in terms of the form factors constructed out of the background field\nstrength tensor ($\\bar{F}_{\\mu\\nu} $) and the same for dynamical photon\n($f^{\\mu\\nu}$); they happen to be $\\bar{F}_{\\mu\\nu}f^{\\mu\\nu}$ and\n${\\tilde{\\bar{F}}_{\\mu\\nu}f^{\\mu\\nu}}$. These form factors transform\ndifferently under CP transformation. While $\\bar{F}_{\\mu\\nu}f^{\\mu\\nu}$\n(describing polarization orthogonal to B ($|\\gamma_{||} >$)) is CP even,\n the other one, ${\\tilde{\\bar{F}}_{\\mu\\nu}f^{\\mu\\nu}}$( describing\npolarization along B ($|\\gamma_\\bot >$), is CP odd. In the interaction\nLagrangian, if the scalar is interchanged with the pseudoscalar, the role of\nthe two form factors just gets interchanged. Thus for nearly degenerate\nstrengths of the coupling constants ( $g_{\\gamma\\gamma\\phi}$ and\n$g_{\\gamma\\gamma _a}$ ) and masses ($m_\\phi$ and $m_a$ ) of the respective\ncandidates, proper identification of one from the other may become very\ndifficult in laboratory or astrophysics based experiments. The basic motivation\nof this investigation is to reduce this uncertainty through incorporation of\nparity violating ({\\it originating through magnetized medium effects }) part of\nthe photon self-energy in the effective Lagrangian. This step, in turn affects\nthe (Pseudo) Scalar Photon mixing dynamics drastically and brings out a\nsignificant change in the spectrum of the electromagnetic beam undergoing such\ninteraction.", "category": "hep-ph" }, { "text": "Multiparton webs beyond three loops: Correlators of Wilson-line operators are fundamental ingredients for the\nstudy of the infrared properties of non-abelian gauge theories. In perturbation\ntheory, they are known to exponentiate, and their logarithm can be organised in\nterms of collections of Feynman diagrams called webs. We study the\nclassification of webs to high perturbative orders, proposing a set of tools to\ngenerate them recursively: in particular, we introduce the concept of Cweb, or\ncorrelator web, which is a set of skeleton diagrams built with connected gluon\ncorrelators, instead of individual Feynman diagrams. As an application, we\nenumerate all Cwebs entering the soft anomalous dimension matrix for\nmulti-parton scattering amplitudes at four loops, and we compute the mixing\nmatrices for all Cwebs connecting four or five Wilson lines at that loop order,\nverifying that they obey sum rules that were derived or conjectured in the\nliterature. Our results provide the colour building blocks for the calculation\nof the soft anomalous dimension matrix at four-loop order.", "category": "hep-ph" }, { "text": "Wilson Expansion of QCD Propagators at Three Loops: Operators of\n Dimension Two and Three: In this paper we construct the Wilson short distance operator product\nexpansion for the gluon, quark and ghost propagators in QCD, including\noperators of dimension two and three, namely, A^2, m^2, m A^2, \\ovl{\\psi} \\psi\nand m^3. We compute analytically the coefficient functions of these operators\nat three loops for all three propagators in the general covariant gauge. Our\nresults, taken in the Landau gauge, should help to improve the accuracy of\nextracting the vacuum expectation values of these operators from lattice\nsimulation of the QCD propagators.", "category": "hep-ph" }, { "text": "Mapping the phase diagram of strongly interacting matter: We employ a conformal mapping to explore the thermodynamics of strongly\ninteracting matter at finite values of the baryon chemical potential $\\mu$.\nThis method allows us to identify the singularity corresponding to the critical\npoint of a second-order phase transition at finite $\\mu$, given information\nonly at $\\mu=0$. The scheme is potentially useful for computing thermodynamic\nproperties of strongly interacting hot and dense matter in lattice gauge\ntheory. The technique is illustrated by an application to a chiral effective\nmodel.", "category": "hep-ph" }, { "text": "The Neutral Higgs Effects on Rare Decays $B \\to X_s l^+ l^-$ in T2HDM: We calculate the new physics contributions to the branching ratios of the\nrare decays $B \\to X_s l^+ l^-$ $(l=e, \\mu)$ induced by neutral Higgs bosons\nloop diagrams in the top quark two-Higgs-doublet model (T2HDM). From the\nnumerical calculations, we find that (a) the neutral Higgs boson's correction\nto $B \\to X_s l^+ l^-$ decays interferes constructively with its standard model\ncounterpart, but small in magnitude; (b) the neutral Higgs contributions to the\nbranching ratio of $B \\to X_s l^+ l^-$ decay can be neglected safely if their\nmasses are larger than 100 GeV and $\\tan\\beta \\leq 40$.", "category": "hep-ph" }, { "text": "$\u03c1$ meson generalized parton distributions in the Nambu--Jona-Lasinio\n model: In this paper, both the unpolarized and the polarized $\\rho$ meson\ngeneralized parton distributions are investigated in the framework of the\nNambu--Jona-Lasinio model using proper time regularization scheme. The symmetry\nproperties of $\\rho$ meson generalized parton distributions are checked. The\nthree independent distribution functions in deep inelastic scattering,\n$F_1(x)$, $b_1(x)$ and $g_1(x)$, and the Sachs-like charge, magnetic, and\nquadruple form factors $G_C(t)$, $G_M(t)$ and $G_Q(t)$, which are the first\nMellin moments of unpolarized generalized parton distributions are obtained. In\naddition, the $u$ quark axial vector form factors $\\tilde{F}_1^u(t)$ and\n$\\tilde{F}_2^u(t)$ related to the axial currents from the polarized generalized\nparton distributions are studied. The impact parameter dependent parton\ndistribution functions, which are the two-dimensional Fourier transform of\ngeneralized parton distributions are studied, too. The obtained $\\rho$ meson\ngeneralized parton distributions satisfy the required properties well.", "category": "hep-ph" }, { "text": "The first-order factorizable contributions to the three-loop massive\n operator matrix elements $A_{Qg}^{(3)}$ and $\u0394A_{Qg}^{(3)}$: The unpolarized and polarized massive operator matrix elements $A_{Qg}^{(3)}$\nand $\\Delta A_{Qg}^{(3)}$ contain first-order factorizable and non-first-order\nfactorizable contributions in the determining difference or differential\nequations of their master integrals. We compute their first-order factorizable\ncontributions in the single heavy mass case for all contributing Feynman\ndiagrams. Moreover, we present the complete color-$\\zeta$ factors for the cases\nin which also non-first-order factorizable contributions emerge in the master\nintegrals, but cancel in the final result as found by using the method of\narbitrary high Mellin moments. Individual contributions depend also on\ngeneralized harmonic sums and on nested finite binomial and inverse binomial\nsums in Mellin $N$-space, and correspondingly, on Kummer-Poincar\\'e and\nsquare-root valued alphabets in Bjorken-$x$ space. We present a complete\ndiscussion of the possibilities of solving the present problem in $N$-space\nanalytically and we also discuss the limitations in the present case to\nanalytically continue the given $N$-space expressions to $N \\in \\mathbb{C}$ by\nstrict methods. The representation through generating functions allows a well\nsynchronized representation of the first-order factorizable results over a\n17-letter alphabet. We finally obtain representations in terms of iterated\nintegrals over the corresponding alphabet in $x$-space, also containing up to\nweight {\\sf w = 5} special constants, which can be rationalized to\nKummer-Poincar\\'e iterated integrals at special arguments. The analytic\n$x$-space representation requires separate analyses for the intervals $x \\in\n[0,1/4], [1/4,1/2], [1/2,1]$ and $x > 1$. We also derive the small and large\n$x$ limits of the first-order factorizable contributions.", "category": "hep-ph" }, { "text": "The single parton fragmentation functions of heavy quarkonium in soft\n gluon factorization: We study the single parton fragmentation functions (FFs) at the input\nfactorization scale $\\mu_0\\gtrsim 2m_Q$, with heavy quark mass $m_Q$, in the\nsoft gluon factorization (SGF) approach. We express the FFs in terms of\nperturbatively calculable short distance hard parts for producing a heavy\nquark-antiquark pair in all possible states, convoluted with corresponding soft\ngluon distribution for the hadronization of the pair to a heavy quarkonium. We\ncompute the perturbative short distance hard parts for producing a heavy quark\npair in all possible $S$-wave and $P$-wave states up to $O(\\alpha_s^2)$. With\nour results, the SGF can be further used to study the heavy quarkonium\nproduction at the hadron colliders and heavy quarkonium production within a\njet.", "category": "hep-ph" }, { "text": "Progress in Lattice QCD Relevant for Flavor Physics: Recent Lattice QCD results relevant for Kaon, Charm and B Physics are\nsummarized. There is general agreement among calculations using a wide range of\ndifferent lattice actions. This bolsters confidence in the lattice results and\nin their quoted errors. One notes considerable progress since CKM2008 in\nreducing lattice errors with some quantities now being calculated at the\nsubpercent to a few percent level accuracy. Much work remains, however, and\nfurther improvements can be expected in the coming years.", "category": "hep-ph" }, { "text": "How suppressed are the radiative interference effects in heavy unstable\n particle production?: We present a \\lq\\lq theorem\" which quantifies, for inclusive processes, the\nlevel of suppression of the radiative interference effects between the\nproduction and decay stages of heavy {\\it unstable} particles. The theorem,\nwhich is based on very general physical arguments, is applicable to all orders\nin the coupling.", "category": "hep-ph" }, { "text": "Light-meson properties from the Bethe-Salpeter equation: We discuss how to extract observables from an inhomogeneous vertex\nBethe-Salpeter equation without resorting to the corresponding homogeneous\nequation. As an example we present a prediction for the $e^+e^-$ decay width of\nthe $\\rho(1450)$ or $\\rho'$ meson. We also attempt to identify the momentum\nrange contributing to a vector meson's decay constant.", "category": "hep-ph" }, { "text": "Linear Collider Signal of a Wino LSP in Anomaly Mediated Scenarios: Selectron (smuon) pair-production in a next generation Linear Collider,\nyielding a fast electron (muon) trigger, a visible heavily ionizing track\nand/or a resolved soft pion impact parameter and overall $\\mET$, is shown to\nprovide a smoking gun signature for Anomaly Mediated Supersymmetry Breaking\nmodels with a neutral Wino as the Lightest Supersymmetric Particle, nearly\nmass-degenerate with the lighter chargino.", "category": "hep-ph" }, { "text": "Parity violating magnetization at neutrino pair emission using trivalent\n lanthanoid ions: A new detection method using magnetization generated at triggered radiative\nemission of neutrino pairs (RENP), $ |e \\rangle \\rightarrow | g \\rangle +\n\\gamma + \\sum_{ij}\\nu_i \\bar{\\nu}_j $ (atomic de-transition from state $|e\n\\rangle $ to state $|g \\rangle$ emitting sum of neutrino pairs\n$\\sum_{ij}\\nu_i\\bar{\\nu}_j$ accompanied by a photon $\\gamma$), is investigated\nin order to determine unknown neutrino properties; absolute neutrino masses of\n$\\nu_i$ and Majorana/Dirac distinction. Magnetization associated with RENP\nevents has parity violating component intrinsic to weak interaction enforced by\ncrystal field effect in solids, and greatly helps background rejection of\nquantum electrodynamic (QED) origin even when these backgrounds are amplified.\nIn proposed experiments we prepare a coherently excited body of trivalent\nlanthanoid ions, Er$^{3+}$ (a best candidate ion so far found), doped in a\ntransparent dielectric crystal. The magnetic moment $\\mu \\langle\n\\vec{S}\\cdot\\vec{k} \\rangle/k $ arising from generated electron spin $\\vec{S}$\nparallel to trigger photon direction $\\vec{k}/k$ is parity odd, and is absent\nin QED processes. The generated magnetic field of order nano gauss is stored in\ncrystals long after pair emission event till spin relaxation time. An improved\ncalculation method of coherent rate and angular distribution of magnetization\nis developed in order to incorporate finite size effect of crystal target\nbeyond the infinite size limit in previous calculations.", "category": "hep-ph" }, { "text": "How Penguins Started to Fly: A mechanism explaining a strong enhancement of nonleptonic weak decays was\nsuggested in 1975, later to be dubbed the penguin. This mechanism extends\nWilson's ideas about the operator product expansion at short distances and\nreveals an intricate interplay of subtle features of the theory such as heavy\nquark masses in Glashow-Iliopoulos-Maini cancellation, light quarks shaping the\nchiral properties of QCD, etc. The penguins have subsequently evolved to play a\nrole in a variety of fields in present-day particle phenomenology. I will\ndescribe the history of this idea and review its subsequent development. The\nrecent measurement of direct CP violation in K decays gives a new confirmation\nof the penguin mechanism.", "category": "hep-ph" }, { "text": "Renormalization Group Effects on the Mass Relation Predicted by the\n Standard Model with Generalized Covariant Derivatives: Renormalization group analysis is made on the relation $m_{\\rm H} \\simeq\n\\sqrt{2}m_t$ for masses of the top quark and the Higgs boson, which is\npredicted by the standard model based on generalized covariant derivatives with\ngauge and Higgs fields. This relation is a low energy manifestation of a tree\nlevel constraint which holds among the quartic Higgs self-coupling constant and\nthe Yukawa coupling constants at a certain high energy scale $\\mu_0$. With the\nrenormalization group equation at one-loop level, the evolution of the\nconstraint is calculated from $\\mu_0$ down to the low energy region around the\nobserved top quark mass. The result of analysis shows that the Higgs boson mass\nis in $m_t \\lesssim m_{\\rm H} \\lesssim \\sqrt{2}m_t$ for a wide range of the\nenergy scale $\\mu_0 \\gtrsim m_t$ and it approaches to 177 GeV ($\\approx m_t$)\nfor large values of $\\mu_0$.", "category": "hep-ph" }, { "text": "Analysis of the $X(6600)$, $X(6900)$, $X(7300)$ and related tetraquark\n states with the QCD sum rules: In this work, we re-investigate the mass spectrum of the ground state, first,\nsecond and third radial excited states of the diquark-antidiquark type\nfully-charm tetraquark states with the QCD sum rules plus Regge trajectories.\nWe take account of the CMS and ATLAS experimental data and preform a\nself-consistent analysis, then try to make possible assignments of the\n$X(6600)$, $X(6900)$ and $X(7300)$ in the picture of tetraquark states with the\n$J^{PC}=0^{++}$ or $1^{+-}$.", "category": "hep-ph" }, { "text": "Neutrino oscillations in the early Universe: We discuss the oscillations effects on neutrinos in the early Universe and\nupdate the cosmological constraints on the oscillation parameters. It is shown\nthat sterile LOW solution to the solar neutrino problem is almost completely\nexcluded from cosmological nucleosynthesis considerations. Two possibilities\nfor the relaxation of this constraint are discussed: high primordial helium-4\nyield and a relic lepton asymmetry present at nucleosynthesis epoch. The\nnumerical analysis proved that Y_p=0.25 only relaxes the constraint on LOW\nsolution, while L > 10^{-5} is capable to remove it.", "category": "hep-ph" }, { "text": "Quirky Explanations for the Diphoton Excess: We propose two simple quirk models to explain the recently reported 750 GeV\ndiphoton excesses at ATLAS and CMS. It is already well-known that a real\nsinglet scalar $\\phi$ with Yukawa couplings $\\phi \\bar X X$ to vector-like\nfermions $X$ with mass $m_X > m_\\phi/2$ can easily explain the observed signal,\nprovided $X$ carries both SM color and electric charge. We instead consider\nfirst the possibility that the pair production of a fermion, charged under both\nSM gauge groups and a confining $SU(3)_v$ gauge group, is responsible. If pair\nproduced it forms a quirky bound state, which promptly annihilates into gluons,\nphotons, v-gluons and possibly SM fermions. This is an extremely minimal model\nto explain the excess, but is already in some tension with existing displaced\nsearches, as well as dilepton and dijet resonance bounds. We therefore propose\na hybrid Quirk-Scalar model, in which the fermion of the simple $\\phi \\bar X X$\ntoy model is charged under the additional $SU(3)_v$ confining gauge group.\nConstraints on the new heavy fermion $X$ are then significantly relaxed. The\nmain additional signals of this model are possible dilepton, dijet and diphoton\nresonances at $\\sim$ 2 TeV or more from quirk annihilation, and the production\nof v-glueballs through quirk annihilation and $\\phi$ decay. The glueballs can\ngive rise to spectacular signatures, including displaced vertices and events\nwith leptons, photons and $Z$-bosons. If the Quirk-Scalar model is responsible\nfor the 750 GeV excess it should be discovered in one of these channels with 20\nor $300 \\mathrm{fb}^{-1}$ of LHC run 2 data.", "category": "hep-ph" }, { "text": "Charged Lepton Spectrum Approximation in a Three Body Nucleon Decay: Only phase space is typically used to obtain final state particle spectra in\nrare decay searches, which is a crude approximation in the case of three body\nprocesses. We will demonstrate how both dynamics and phase space can be\napproximately accounted for, in processes such as nucleon decays $p \\rightarrow\ne^+ \\bar{\\nu} \\nu$ or $p \\rightarrow \\mu^+ \\bar{\\nu} \\nu$ originating from\nGrand Unification models, using general effective Fermi theory formalism of\nelectroweak muon decay $\\mu \\rightarrow e^+ \\bar{\\nu} \\nu$. This approach\nallows for a more precise and only weakly model dependent approximation of\nfinal particle spectra for these and similar decays, which may improve rare\nprocess searches in current and near-future experiments.", "category": "hep-ph" }, { "text": "Threshold effects on prediction for proton decay in non-supersymmetric\n $E_6$ GUT with intermediate trinification symmetry: We consider a non-supersymmetric $E_6$ Grand Unified Theory (GUT) with\nintermediate trinification symmetry $SU(3)_C \\times SU(3)_L \\times SU(3)_R\n\\times D$ (D denoted as D-parity for discrete left-right symmetry) and study\nthe effect of one-loop threshold corrections arising due to every class of\nsuperheavy particles (scalars, fermions and vectors). It is observed that, the\nintermediate mass scale $M_I$ and $\\sin^2\\theta_W$ remain unaffected by GUT\nthreshold contributions. The threshold modified unification mass scale $M_U$ is\nin excellent agreement with the present experimental proton decay constraint.\nThe novel feature of the model is that GUT threshold uncertainty of $M_U$ is\nfound to be controlled by superheavy scalars only, leading to a very predictive\nscenario for proton decay, which can be verifiable within the foreseeable\nexperiments.", "category": "hep-ph" }, { "text": "Definition and Evolution of Transverse Momentum Distributions: We consider the definition of unpolarized transverse-momentum-dependent\nparton distribution functions while staying on-the-light-cone. By imposing a\nrequirement of identical treatment of two collinear sectors, our approach,\ncompatible with a generic factorization theorem with the soft function\nincluded, is valid for all non-ultra-violet regulators (as it should), an issue\nwhich causes much confusion in the whole field. We explain how large logarithms\ncan be resummed in a way which can be considered as an alternative to the use\nof Collins-Soper evolution equation. The evolution properties are also\ndiscussed and the gauge-invariance, in both classes of gauges, regular and\nsingular, is emphasized.", "category": "hep-ph" }, { "text": "High Energy Photon-Photon and Electron-Photon Collisions: The advent of a next linear $e^\\pm e^-$ collider and back-scatterd laser\nbeams will allow the study of a vast array of high energy processes of the\nStandard Model through the fusion of real and virtual photons and other gauge\nbosons. As examples, I discuss virtual photon scattering $\\gamma^* \\gamma^* \\to\nX$ in the region dominated by BFKL hard Pomeron exchange and report the\npredicted cross sections at present and future $e^\\pm e^-$ colliders. I also\ndiscuss exclusive $\\gamma \\gamma$ reactions in QCD as a measure of hadron\ndistribution amplitudes and a new method for measuring the anomalous magnetic\nand quadrupole moments of the $W$ and $Z$ gauge bosons to high precision in\npolarized electron-photon collisions.", "category": "hep-ph" }, { "text": "Restoration of Parity and the Right-Handed Analog of the CKM Matrix: In a recent Letter we determined analytically the right-handed quark mixing\nmatrix in the minimal Left-Right symmetric theory with generalized Parity. We\nderived its explicit form as a series expansion in a small parameter that\nmeasures the departure from hermiticity of quark mass matrices. Here we analyze\ncarefully the convergence of the series by including higher order terms and by\ncomparing with numerical results. We apply our findings to some\nphenomenological applications such as the production and decays of the\nright-handed gauge boson $W_R$, the neutrinoless double beta decay, the decays\nof the heavy scalar doublet, the strong CP parameter and the theoretical limits\non the new mass scale from the $K$ and $B$-meson physics. In particular, we\ndemonstrate that the relevant coupling for the production of the $W_R$ gauge\nboson at hadronic colliders and for the neutrinoless double beta decay equals\nits left-handed counterpart, within a percent. We also demonstrate that the\nstability of the theoretical lower limit on the $W_R$ mass from the $K$-meson\nphysics is due to a partial cancellation of the external phases of the\nright-handed mixing matrix.", "category": "hep-ph" }, { "text": "Azimuthal angles in diffractive ep collisions: We investigate azimuthal correlations in deep inelastic diffractive\nscattering, e + p -> e + \\tilde{p} + X. The dependence of the ep cross section\non the angle between the lepton plane and some direction in the hadronic final\nstate can be written in a simple form; its measurement can be used to constrain\nthe cross section for longitudinally polarised photons. Using the model of\nnonperturbative two-gluon exchange of Landshoff and Nachtmann we calculate the\ndistribution of the azimuthal jet angle in diffractive dijet production and\nfind that useful bounds on the longitudinal cross section for such events might\nbe obtained from its measurement. We then discuss the predictions of this model\nfor the dependence of the ep cross section on the azimuthal angle of the proton\nremnant \\tilde{p}, which contains information about the helicity content of the\npomeron.", "category": "hep-ph" }, { "text": "SuperIso program and flavor data constraints: We present here an overview of the SuperIso program which is a public code\ndedicated to the calculation of flavor physics observables in supersymmetry.\nThe main purpose of the SuperIso program is to provide, by confronting the\ntheoretical predictions to the experimental data for flavor observables,\nindirect constraints on the parameters of supersymmetry. These constraints can\nthen provide limits on physical masses of yet undiscovered new particles, such\nas charged Higgs bosons.", "category": "hep-ph" }, { "text": "Light diffraction by a strong standing electromagnetic wave: The nonlinear quantum interaction of a linearly polarized x-ray probe beam\nwith a focused intense standing laser wave is studied theoretically. Because of\nthe tight focusing of the standing laser pulse, diffraction effects arise for\nthe probe beam as opposed to the corresponding plane wave scenario. A\nquantitative estimate for realistic experimental conditions of the ellipticity\nand the rotation of the main polarization plane acquired by the x-ray probe\nafter the interaction shows that the implementation of such vacuum effects is\nfeasible with future X-ray Free Electron Laser light.", "category": "hep-ph" }, { "text": "Spin-dependent Pomeron and Odderon in elastic proton-proton scattering: We introduce a new model of near-forward elastic proton-(anti)proton\nscattering at high energy based on the modern formulation of Pomeron and\nOdderon in terms of Wilson lines and generalized TMDs (GTMDs). We compute the\nhelicity-dependent elastic amplitudes $\\phi_{1,2,3,4,5}$ in this model and\nstudy their energy dependence from the nonlinear small-$x$ evolution equations.\nWhile both Pomeron and Odderon contribute to helicity-flip processes in\ngeneral, in the forward limit $t=0$ only the double helicity-flip amplitude\n$\\phi_2$, dominated by the spin-dependent Odderon, survives. This may affect\nthe extraction of the $\\rho$ parameter as well as the total cross section in\nthe LHC energy domain and beyond.", "category": "hep-ph" }, { "text": "A two particle hidden sector and the oscillations with photons: We present a detailed study of the oscillations and optical properties for\nvacuum, in a model for the dark sector that contains axion-like particles and\nhidden photons. In this model, both can couple to photons. We provide bounds\nfor the couplings versus the mass, using current results from ALPS-I and PVLAS.\nWe also discuss the challenges for the detection of models with more than one\nhidden particle in light shining trough wall-like experiments.", "category": "hep-ph" }, { "text": "Topics in Electroweak Physics: We briefly discuss five topics in Precision Electroweak Physics: i) the\nrecently proposed Effective Scheme of Renormalization, ii) evidence for\nelectroweak bosonic corrections derived from the radiative correction\nDelta_r_eff, iii) an approach to estimate the scale of new physics in a\nhypothetical Higgs-less scenario, iv) simple and accurate formulae for s^2_eff,\nM_W, Gamma_l, and their physical applications, v) a recent proposal concerning\nthe field renormalization constant for unstable particles.", "category": "hep-ph" }, { "text": "On Distinguishing Radions From Higgs Bosons: Radion couplings are almost identical to Higgs boson couplings, making it\nvery difficult to distinguish the two states when the radion mass and vacuum\nexpectation value are similar to those of the Higgs boson. The only real\ndifference lies in the fact that the coupling of radions to off-shell fermions\nis proportional to the momentum rather than the mass of the fermion. This extra\ncontribution gets cancelled in all tree-level processes and shows up only in\nloop-induced processes like Phi -> gamma gamma and Phi -> gg. We perform a\ncareful calculation of the branching ratios and establish that they can prove\ncrucial in clearly distinguishing a radion from a Higgs boson. This claim is\nmade concrete by evaluating the exclusive cross-sections in a radiative process\ninvolving elementary scalars.", "category": "hep-ph" }, { "text": "Pairing Phase Transitions of Matter under Rotation: The phases and properties of matter under global rotation have attracted much\ninterest recently. In this paper we investigate the pairing phenomena in a\nsystem of fermions under the presence of rotation. We find that there is a\ngeneric suppression effect on pairing states with zero angular momentum. We\ndemonstrate this effect with the chiral condensation and the color\nsuperconductivity in hot dense QCD matter as explicit examples. In the case of\nchiral condensation, a new phase diagram in the temperature-rotation parameter\nspace is found, with a nontrivial critical point.", "category": "hep-ph" }, { "text": "Translation of Time-Reversal Violation in the Neutral K-Meson System\n into a Table-Top Mechanical System: Weak interactions break time-reversal (T) symmetry in the two-state system of\nneutral K mesons. We present and discuss a two-state mechanical system, a\nFoucault-type pendulum on a rotating table, for a full representation of K0\nK0bar transitions by the pendulum motions including T violation. The pendulum\nmoves with two different oscillation frequencies and two different magnetic\ndampings. Its equation of motion is identical with the differential equation\nfor the real part of the CPT-symmetric K-meson wave function. The pendulum is\nable to represent microscopic CP and T violation with CPT symmetry owing to the\nmacroscopic Coriolis force which breaks the symmetry under reversal-of-motion.\nVideo clips of the pendulum motions are shown as supplementary material.", "category": "hep-ph" }, { "text": "Intrinsic transverse momentum and transverse spin asymmetries: We investigate leading twist transverse momentum dependent origins of\ntransverse spin asymmetries in hadron-hadron collisions. The chiral-odd T-odd\ndistribution function with intrinsic transverse momentum dependence, which\nwould signal an intrinsic handedness of quarks inside a hadron, could account\nfor single spin asymmetries and at the same time for the large cos(2 phi)\nasymmetry in the unpolarized Drell-Yan cross section, which still lacks\nunderstanding. We show explicitly how it would relate unpolarized and polarized\nobservables measurable with proton-proton collisions at RHIC. It would offer a\nnew possibility to access the transversity distribution function.", "category": "hep-ph" }, { "text": "Autoencoders for Semivisible Jet Detection: The production of dark matter particles from confining dark sectors may lead\nto many novel experimental signatures. Depending on the details of the theory,\ndark quark production in proton-proton collisions could result in semivisible\njets of particles: collimated sprays of dark hadrons of which only some are\ndetectable by particle collider experiments. The experimental signature is\ncharacterised by the presence of reconstructed missing momentum collinear with\nthe visible components of the jets. This complex topology is sensitive to\ndetector inefficiencies and mis-reconstruction that generate artificial missing\nmomentum. With this work, we propose a signal-agnostic strategy to reject\nordinary jets and identify semivisible jets via anomaly detection techniques. A\ndeep neural autoencoder network with jet substructure variables as input proves\nhighly useful for analyzing anomalous jets. The study focuses on the\nsemivisible jet signature; however, the technique can apply to any new physics\nmodel that predicts signatures with anomalous jets from non-SM particles.", "category": "hep-ph" }, { "text": "Final state strong interaction constraints on weak D0 -> K0S pi+ pi-\n decay amplitudes: Weak decay tree and annihilation - t-channel W - exchange amplitudes for the\nD0 -> K0S pi+ pi- process are calculated using quasi two-body QCD factorization\napproach and unitarity constraints. Final state strong kaon-pion and pion-pion\ninteractions in S, P and D waves are described through corresponding form\nfactors including many resonances. Preliminary results compare well with the\neffective mass distributions of the Belle and BABAR Collaboration analyses.", "category": "hep-ph" }, { "text": "Should we still believe in constrained supersymmetry?: We calculate Bayes factors to quantify how the feasibility of the constrained\nminimal supersymmetric standard model (CMSSM) has changed in the light of a\nseries of observations. This is done in the Bayesian spirit where probability\nreflects a degree of belief in a proposition and Bayes' theorem tells us how to\nupdate it after acquiring new information. Our experimental baseline is the\napproximate knowledge that was available before LEP, and our comparison model\nis the Standard Model with a simple dark matter candidate. To quantify the\namount by which experiments have altered our relative belief in the CMSSM since\nthe baseline data we compute the Bayes factors that arise from learning in\nsequence the LEP Higgs constraints, the XENON100 dark matter constraints, the\n2011 LHC supersymmetry search results, and the early 2012 LHC Higgs search\nresults. We find that LEP and the LHC strongly shatter our trust in the CMSSM\n(with $M_0$ and $M_{1/2}$ below 2 TeV), reducing its posterior odds by a factor\nof approximately two orders of magnitude. This reduction is largely due to\nsubstantial Occam factors induced by the LEP and LHC Higgs searches.", "category": "hep-ph" }, { "text": "Finite Theories and the SUSY Flavor Problem: We study a finite SU(5) grand unified model based on the non-Abelian discrete\nsymmetry A_4. This model leads to the democratic structure of the mass matrices\nfor the quarks and leptons. In the soft supersymmetry breaking sector, the\nscalar trilinear couplings are aligned and the soft scalar masses are\ndegenerate, thus solving the SUSY flavor problem.", "category": "hep-ph" }, { "text": "Dark matter annihilation into leptons through gravity portals: Dark matter (DM) constitutes 85% of the matter in the Universe. However, its\nspecific particle property is still unclear. The fundamentals of DM particles\nsubject to gravitational interaction, and that the lepton excess in cosmic rays\nmay originate from DM particles, inspired us to investigate DM particle\nproperties beyond the standard model. We assume that a leptophilic SU(2)\ndoublet exists in nature as the mediator connecting DM with visible leptons.\nSince general relativity is not renormalizable at the quantum level, it should\nbe regarded as an effective field theory's leading order term. One species of\nthe next-to-leading-order term should be operators linear to the Ricci scalar\nand containing scalar fields, such as the Higgs field, scalar DM, or the newly\nintroduced SU(2) scalar doublet. These operators can cause DM annihilation\nthrough gravity portals. We analyzed constraints from the cosmic antiproton\nflux, DM relic abundance, cosmic positron flux, cosmic microwave background,\nand direct detection experiments. The result shows that there is a vast\nparameter space that is compatible with current experiments. DM with a mass of\nelectroweak scale is only allowed to annihilate into leptons. We further show\nthat the purely gravitational DM better explains the DArk Matter Particle\nExplorer cosmic lepton excess. Our work provides a promising mechanism for DM\nparticles to connect with standard model particles.", "category": "hep-ph" }, { "text": "Explaining jet quenching with perturbative QCD alone: We present a new formulation of jet quenching in perturbative QCD beyond the\neikonal approximation. Multiple scattering in the medium is modelled through\ninfra-red-continued (2 -> 2) scattering matrix elements in QCD and the parton\nshower describing further emissions. The interplay between these processes is\narranged in terms of a formation time constraint such that coherent emissions\ncan be treated consistently. Emerging partons are hadronised by the Lund string\nmodel, tuned to describe LEP data in conjunction with the parton shower. Based\non this picture we obtain a good description of the nuclear modification factor\nR_AA at RHIC and LHC.", "category": "hep-ph" }, { "text": "Neutrino mass generation from the perspective of presymmetry: The Standard Model (SM) with one right-handed neutrino per generation is\nrevisited with presymmetry being the global $U(1)_{B-L}$ symmetry of an\nelectroweak theory of leptons and quarks with initially postulated symmetric\nfractional charges. The cancellation of gauge anomalies and the\nnon-perturbative normalization of lepton charges proceed through the mixing of\nlocal and topological charges, the global $B-L$ measuring the induced charge\nassociated with a unit of topological charge, and the mathematical replacement\nof the original fractional charges with the experimentally observed ones. The\n$U(1)_{B-L}$ symmetry of the SM with Dirac neutrinos is seen as a residual\npresymmetry. High-scale and low-scale seesaw mechanisms proposed to explain the\nmass of neutrinos are examined from the perspective of presymmetry, be they of\nMajorana or pseudo-Dirac type. We find that the tiny mass splitting in\npseudo-Dirac neutrinos and the mass of heavy neutrinos ride on the opposite\nends of the seesaw. We show that pseudo-Dirac neutrinos contain extra sterile\nneutrinos with imprints of presymmetry and for heavy ones we get constraints\nfavoring the low-scale linear seesaw over the inverse variant.", "category": "hep-ph" }, { "text": "Measuring $|V_{ub}|$ at future B-Factories: We calculate the so--called Fermi motion parameter $p_{_F}$ of ACCMM model\nusing the variational method in a potential model approach. We also propose\nhadronic invariant mass distribution as an alternative experimental observable\nto measure $V_{ub}$ at future asymmetric $B$ factories.", "category": "hep-ph" }, { "text": "Application of a Revised Moliere Theory to the Description of the\n Landau-Pomeranchuk Effect: Using the Coulomb corrections to some important parameters of a revised\nMoliere multiple scattering theory, we have obtained analytically and\nnumerically the Coulomb corrections to the quantities of the Migdal theory of\nthe Landau-Pomeranchuk (LPM) effect for sufficiently thick targets. We showed\nthat the Coulomb correction to the spectral bremsstrahlung rate of this theory\nallows completely eliminating the discrepancy between the theory and experiment\nat leastfor high Z experimental targets.", "category": "hep-ph" }, { "text": "Meson Production and Spectroscopy at HERA: Selected recent results from the H1 and ZEUS experiments are reviewed,\nillustrating some of the many facets of ``meson physics'' at the HERA ep\ncollider. The results cover exclusive elastic and proton-dissociative\ndiffractive vector meson production and comparisons with recent theoretical\ncalculations show that perturbative QCD models are successful in describing\nthese processes when at least one of the involved scales have large values.\nFurthermore a search for odderon induced exclusive photoproduction of\npseudoscalar and tensor mesons is described; upper limits for the cross\nsections are below recent theoretical predictions. Finally the status of open\ncharm meson spectroscopy in inclusive final states is reported.", "category": "hep-ph" }, { "text": "Radiative decays \\$D^*_{(s)}\\to D_{(s)}\u03b3$ in covariant confined\n quark model: Radiative decays $D^*_{(s)}\\to D_{(s)}\\gamma$ are revisited in light of new\nexperimental data from the \\textit{BABAR} and BESIII collaborations. The\nradiative couplings $g_{D^*D\\gamma}$ encoding nonperturbative QCD effects are\ncalculated in the framework of the covariant confined quark model developed by\nus. We compare our results with other theoretical studies and experimental\ndata. The couplings (in $\\textrm{GeV}^{-1}$) $|g_{D^{*+}D^+\\gamma}| = 0.45(9)$\nand $|g_{D^{*0}D^0\\gamma}| = 1.72(34)$ calculated in our model agree with the\ncorresponding experimental data $|g_{D^{*+}D^+\\gamma}|=0.47(7)$ and\n$|g_{D^{*0}D^0\\gamma}|=1.77(16)$. The most interesting case is the decay\n$D^*_s\\to D_s\\gamma$, for which a recent prediction based on light-cone sum\nrules at next-to-leading order $|g_{D^*_s D_s\\gamma}|=0.60(19)$ deviates from\nthe first (and only to date) lattice QCD result $|g_{D^*_s D_s\\gamma}|=0.11(2)$\nat nearly $3\\sigma$. Our calculation yields $|g_{D^*_s D_s\\gamma}|=0.29(6)$,\nwhich falls somehow between the two mentioned results, although it is larger\nthan those predicted in other studies using quark models or QCD sum rules.", "category": "hep-ph" }, { "text": "Power Counting For and Symmetries of the Effective Field Theory For NN\n Interactions: The appropriate power counting for the effective field theory of NN\ninteractions is reviewed. It is more subtle than in most effective field\ntheories since in the limit that the S-wave NN scattering lengths go to\ninfinity it is governed by a nontrivial fixed point. The leading two body terms\nin the effective field theory for nucleon self interactions are scale invariant\nand invariant under Wigner SU(4) spin-isospin symmetry in this limit. Higher\nbody terms with no derivatives (i.e., three and four body terms) are\nautomatically invariant under Wigner symmetry.", "category": "hep-ph" }, { "text": "Quarkonium production in hadronic collisions: We summarize the theoretical description of charmonium and bottonium\nproduction in hadronic collisions and compare it to the available data from\nhadron-nucleon interactions. With the parameters of the theory established by\nthese data, we obtain predictions for quarkonium production at RHIC and LHC\nenergies.", "category": "hep-ph" }, { "text": "Inclusive Quark Production in $e^{+}e^{-}$-Annihilation - A Path\n Integral Approach: The single-particle inclusive differential cross-section for a reaction\n$a+b\\to c+X$ is written as imaginary part of a correlation function in a\nforward scattering amplitude for $a+b\\to a+b$ in a modified effective theory.\nIn this modified theory the interaction Hamiltonian $\\tilde H_I$ equals $H_I$\nof the original theory up to a certain time. Then there is a sign change and\n$\\tilde H_I$ becomes nonlocal. This is worked out in detail for scalar field\nmodels and for QED plus the abelian gluon model. A suitable path integral for\ndirect calculations of inclusive cross sections is presented.", "category": "hep-ph" }, { "text": "Mixed QCD-electroweak corrections to Higgs boson production in gluon\n fusion: We compute the 3-loop O(\\alpha \\alpha_s) correction to the Higgs boson\nproduction cross section arising from light quarks using an effective theory\napproach. Our calculation probes the factorization of QCD and electroweak\nperturbative corrections to this process. We combine our results with the best\ncurrent estimates for contributions from top and bottom quarks to derive an\nupdated theoretical prediction for the Higgs boson production cross section in\ngluon fusion. With the use of the MSTW 2008 parton distribution functions that\ninclude the newest experimental data, our study results in cross sections\napproximately 4-6% lower for intermediate Higgs boson masses than those used in\nrecent Tevatron analyses that imposed a 95% confidence level exclusion limit of\na Standard Model Higgs boson with M_H=170 GeV.", "category": "hep-ph" }, { "text": "Bs to mu mu gamma from Bs to mu mu: The Bs to mu mu gamma decay offers sensitivity to a wider set of effective\noperators than its non-radiative counterpart Bs to mu mu, and a set that is\ninteresting in the light of present-day discrepancies in flavour data. On the\nother hand, the direct measurement of the Bs to mu mu gamma decay poses\nchallenges with respect to the Bs to mu mu one. We present a novel strategy to\nsearch for Bs to mu mu gamma decays in the very event sample selected for Bs to\nmu mu searches. The method consists in extracting the Bs to mu mu gamma\nspectrum as a \"contamination\" to the Bs to mu mu one, as the signal window for\nthe latter is extended downward with respect to the peak region. We provide\narguments for the actual practicability of the method already on Run-2 data of\nthe LHC.", "category": "hep-ph" }, { "text": "Exotic and nonexotic magnetic transitions in the context of the SELEX\n and GRAAL experiments: We calculate magnetic transition moments in the chiral quark-soliton model,\nwith explicit SU(3)-symmetry breaking taken into account. The dynamical model\nparameters are fixed by experimental data for the magnetic moments of the\nbaryon octet and from the recent measurements of $\\Theta^{+}$ mass. Known\nmagnetic transition moments $\\mu_{\\Lambda\\Sigma}$, $\\mu_{N\\Delta}$ are\nreproduced and predictions for other octet-decuplet and octet-antidecuplet\ntransitions are given. In particular $\\mu_{\\Sigma\\Sigma^{\\ast}}$ recently\nconstrained by SELEX is shown to be below $0.82 \\mu_N$. The recent GRAAL data\non $\\eta$ photoproduction off the nucleon are explained in terms of a new\nnarrow antidecuplet neutron-like resonance.", "category": "hep-ph" }, { "text": "Magnetic Moment of Leptons: We show that the magnetic moment of leptons is significantly modified in\nthermal background as compared to the corresponding vacuum value. We compare\nthe magnetic moment of all different leptons near nucleosynthesis. It is shown\nthat the significance of thermal corrections depends on the temperature of the\nuniverse and the respective lepton mass. In the early universe, particle mass\nwas growing quadratically with temperature which affects the corresponding\nvalue of magnetic moment. Intrinsic magnetic moment is inversely proportional\nto mass whereas thermal corrections to the neutrino dipole moment is\nproportional to neutrino mass for the Dirac type neutrino in the minimal\nstandard model. Therefore the effect of temperature is not the same for charged\nleptons and neutrinos.", "category": "hep-ph" }, { "text": "Mirror model for sterile neutrinos: Sterile neutrinos are studied as subdominant contribution to solar neutrino\nphysics. The mirror-matter neutrinos are considered as sterile neutrinos. We\nuse the symmetric mirror model with gravitational communication between mirror\nand visible sectors. This communication term provides mixing between visible\nand mirror neutrinos with the basic scale mu=v^2/M_Pl=5*10^-6 eV, where v=174\nGeV is the vacuum expectation value of the standard electroweak group and M_Pl\nis the Planckian mass. It is demonstrated that each mass eigenstate of active\nneutrinos splits into two states separated by small Delta m^2. Unsuppressed\noscillations between active and sterile neutrinos nu_a --> nu_s occur only in\ntransitions between each of these close pairs (``windows''). These oscillations\nare characterized by very small Delta m^2 and can suppress the flux and distort\nspectrum of pp-neutrinos in detectable way. The other observable effect is\nanomalous seasonal variation of neutrino flux, which appears in LMA solution.\nThe considered subdominant neutrino oscillations nu_a <--> nu_s can reveal\nitself as big effects in observations of supernova neutrinos and high energy\n(HE) neutrinos. In the case of HE neutrinos they can provide a very large\ndiffuse flux of active neutrinos unconstrained by the e-m cascade upper limit.", "category": "hep-ph" }, { "text": "Isolated prompt photon pair production at hadron colliders with\n kt-factorization: In the framework of the kt-factorization approach, the isolated prompt photon\npair production in pp and p \\bar p collisions at high energies is studied. The\nconsideration is based on the quark-antiquark annihilation, quark-gluon\nscattering and gluon-gluon fusion subprocesses, where the non-zero transverse\nmomenta of incoming partons are taken into account. The unintegrated quark and\ngluon densities in a proton are determined using the Kimber-Martin-Ryskin\nprescription. The numerical analysis covers the total and differential\nproduction cross sections and extends to specific angular correlations between\nthe produced prompt photons. Theoretical uncertainties of our evaluations are\nstudied and comparison with the NLO pQCD calculations is performed. The\nnumerical predictions are compared with the recent experimental data taken by\nthe D0, CDF, CMS and ATLAS collaborations at the Tevatron and LHC energies.", "category": "hep-ph" }, { "text": "Spontaneous Peccei-Quinn symmetry breaking renders sterile neutrino,\n axion and $\u03c7$boson to be candidates for dark matter particles: We study the Peccei-Quinn (PQ) symmetry of the sterile right-handed neutrino\nsector and the gauge symmetries of the Standard Model. Due to four-fermion\ninteractions, spontaneous breaking of these symmetries at the electroweak scale\ngenerates top-quark Dirac mass and sterile-neutrino Majorana mass. The top\nquark channel yields massive Higgs, $W^\\pm$ and $Z^0$ bosons. The sterile\nneutrino channel yields the heaviest sterile neutrino Majorana mass, sterile\nNambu-Goldstone axion (or majoron) and massive scalar $\\chi$boson. Four-fermion\noperators effectively induce their tiny couplings to SM particles. We show that\na sterile QCD axion is the PQ solution to the strong CP problem. The lightest\nand heaviest sterile neutrinos ($m_N^e\\sim 10^2$ keV and $m_N^\\tau\\sim 10^2$\nGeV), a sterile QCD axion ($m_a< 10^{-8}$ eV, $g_{a\\gamma}< 10^{-13} {\\rm\nGeV}^{-1}$) and a Higgs-like $\\chi$boson ($m_\\chi\\sim 10^2$ GeV) can be dark\nmatter particle candidates, for the constraints of their tiny couplings and\nlong lifetimes inferred from the $W$-boson decay width, Xenon1T and precision\nfine-structure-constant experiments. The axion and $\\chi$boson couplings to SM\nparticles are below the values reached by current laboratory experiments and\nastrophysical observations for directly or indirectly detecting dark matter\nparticles.", "category": "hep-ph" }, { "text": "Relativistic corrections to the semi-inclusive decay of $\\bm\u03c8$ and\n $\\bm\u03a5$: In the framework of the nonrelativistic quantum chromodynamics factorization\nformalism, we study the processes of $\\psi(nS)$ and $\\Upsilon(nS)$ decay into a\nlepton pair or a charm pair associated with two jets up to the next-to-leading\norder in velocity expansion. We present the analytic expressions for the\ndifferential decay rate to the invariant mass of the lepton pair or charm pair.\nWe find that the ratio of the next-to-leading order short-distance coefficient\nto the leading order one is in the range from -5.5 to -12.4. The relativistic\ncorrections are so large that they modify the leading order prediction\nsignificantly. Utilizing the analytic expressions, we also investigate the\nrelativistic corrections in different kinematic regions and their dependence on\nthe masses of the initial-state quarkonium and the final-state fermion. In\naddition, we study the momentum distribution of $D^{*+}$ in the process\n$\\Upsilon(1S)\\to c\\bar{c}gg\\to D^{*+}X$.", "category": "hep-ph" }, { "text": "Detecting Boosted Dark Photons with Gaseous Detectors: We search for indirect signals of $\\mathscr{O}$(keV) dark matter annihilating\nor decaying into $\\mathscr{O}$(eV) dark photons. These dark photons will be\nhighly boosted and have decay lengths larger than the Milky Way, and can be\nabsorbed by neutrino or dark matter experiments at a rate dependent on the\nphoton-dark photon kinetic mixing parameter and the optical properties of the\nexperiment. We show that current experiments can not probe new parameter space,\nbut future large-scale gaseous detectors with low backgrounds (i.e. CYGNUS,\nNEXT, PANDAX-III) may be sensitive to this signal when the annihilation cross\nsection is especially large.", "category": "hep-ph" }, { "text": "Contributions of order ${\\cal O}(m_{\\rm quark}^2)$ to $K_{\\ell 3}$ form\n factors and unitarity of the CKM matrix: The form factors for the $K_{\\ell 3}$ semileptonic decay are computed to\norder $O(p^4)$ in generalized chiral perturbation theory. The main difference\nwith the standard $O(p^4)$ expressions consists in contributions quadratic in\nquark masses, which are described by a single divergence-free low-energy\nconstant, $A_3$. A new simultaneous analysis is presented for the CKM matrix\nelement $V_{us}$, the ratio $F_K/F_{\\pi}$, $K_{\\ell 3}$ decay rates and the\nscalar form factor slope $\\lambda_0$. This framework easily accommodates the\nprecise value for $V_{ud}$ deduced from superallowed nuclear $\\beta$-decays.", "category": "hep-ph" }, { "text": "Structure of Pion Photoproduction Amplitudes: We derive and apply the finite energy sum rules to pion photoproduction. We\nevaluate the low energy part of the sum rules using several state-of-the-art\nmodels. We show how the differences in the low energy side of the sum rules\nmight originate from different quantum number assignments of baryon resonances.\nWe interpret the observed features in the low energy side of the sum rules with\nthe expectation from Regge theory. Finally, we present a model, in terms of a\nRegge-pole expansion, that matches the sum rules and the high-energy\nobservables.", "category": "hep-ph" }, { "text": "Specific Dark Matter signatures from hidden U(1): Several constructions motivate the existence of a dark $U(1)_D$ gauge boson\nwhich interacts with the Standard Model only through its kinetic mixing or loop\ninduced processes. We describe two typical examples with specific signatures in\nparticular we show that a region with relatively light WIMPS, $M_{Z_D}\\lsim 40$\nGeV and a kinetic mixing $10^{-4} \\lsim \\delta \\lsim 10^{-3} $ is not yet\nexcluded by the last experimental data and seems to give promising signals in a\nnear future. We also show that conditions from anomaly cancelation generate\ntri-vector couplings $Z_D Z \\gamma$ leading to a specific gamma ray line\nobservable by FERMI telescope.", "category": "hep-ph" }, { "text": "Implication of Super-Kamiokande Data on R-parity Violation: R-parity violating bilinear (soft) terms in the supersymmetric standard model\nwould be the leading source for nonzero neutrino masses and mixing. We point\nout that the mixing between neutralinos (charginos) and neutrinos (charged\nleptons) driven by the bilinear terms take factorized forms, which may enable\nus to probe the neutrino mixing parameters in a collider. It is then shown that\nthe Super-Kamiokande data on atmospheric neutrinos require all the baryon\nnumber violating couplings to be substantially suppressed: $\\lambda''_{\\rm any}\n<10^{-9}$.", "category": "hep-ph" }, { "text": "Interplay of Hard and Soft Processes at JLab Energies: Even at moderate energy machines, there is a regime where hard pion\nelectroproduction proceeds by a perturbatively calculable process. The process,\nwe claim, is not the leading twist fragmentation one but rather a higher twist\nprocess that produces kinematically isolated pions. Semiexclusive data may\nteach us more about parton distribution functions of the target and the pion\ndistribution amplitude. In addition, there is a connection to generalized\nparton distribution calculations of exclusive processes in that the\nperturbative kernel is the same.", "category": "hep-ph" }, { "text": "New Pattern of Chiral Symmetry Restoration: In this talk I summarize our recent works on the chiral symmetry restoration\nin the large flavor QCD using the hidden local symmetry (HLS) as an effective\nfield theory of QCD. Bare parameters in the HLS are determined by matching the\nHLS with QCD at the matching scale through the Wilsoninan matching conditions.\nThis Wilsonian matching leads to the vector manifestation of the Wigner\nrealization of the chiral symmetry in which the symmetry is restored by the\nmassless degenerate pion (and its flavor partners) and rho meson (and its\nflavor partners) as the chiral partner.", "category": "hep-ph" }, { "text": "Direct stau production at the LHC: We investigate the direct production of supersymmetric scalar taus at the\nLHC. We present the general calculation of the dominant cross section\ncontributions for hadronic stau pair production within the MSSM, taking into\naccount left-right mixing of the stau eigenstates. We find that b-quark\nannihilation and gluon fusion can enhance the cross sections by more than one\norder of magnitude with respect to the Drell-Yan predictions. For long-lived\nstaus, we consider CMSSM parameter regions with such enhanced cross sections\nand possible consequences from recent searches. We find that regions of\nexceptionally small stau yields, favoured by cosmology, are in tension with a\nrecent CMS limit on m_stau.", "category": "hep-ph" }, { "text": "Correlation of Theoretical Uncertainties in PDF Fits and Theoretical\n Uncertainties in Predictions: We show how to account for correlations between theoretical uncertainties\nincorporated in parton distribution function (PDF) fits, and the theoretical\nuncertainties in the predictions made using these PDFs. We demonstrate by\nexplicit calculations, both analytical and numerical, that these correlations\ncan lead to corrections to the central values of the predictions, and\nreductions in both the PDF uncertainties and the theoretical uncertainties in\nthe prediction. We illustrate our results with predictions for top production\nrapidity distributions and the Higgs total cross-section at the LHC, using the\nNLO NNPDF3.1 PDF set which incorporates missing higher order uncertainties. We\nconclude that the inclusion of correlations can increase both the accuracy and\nprecision of predictions involving PDFs, particularly for processes with data\nalready included in the PDF fit.", "category": "hep-ph" }, { "text": "Cosmology and New Physics: A comparison of the standard models in particle physics and in cosmology\ndemonstrates that they are not compatible, though both are well established.\nBasics of modern cosmology are briefly reviewed. It is argued that the\nmeasurements of the main cosmological parameters are achieved through many\nindependent physical phenomena and this minimizes possible interpretation\nerrors. It is shown that astronomy demands new physics beyond the frameworks of\nthe (minimal) standard model in particle physics. More revolutionary\nmodifications of the basic principles of the theory are also discussed.", "category": "hep-ph" }, { "text": "Lepton Flavor Violating Process in Bi-maximal texture of Neutrino\n Mixings: We investigate the lepton flavor violation in the framework of the MSSM with\nright-handed neutrinos taking the large mixing angle MSW solution in the\nquasi-degenerate and the inverse-hierarchical neutrino masses. We predict the\nbranching ratio of $\\mu \\to e+\\gamma$ and $\\tau \\to \\mu+\\gamma$ processes\nassuming the degenerate right-handed Majorana neutrino masses. We find that the\nbranching ratio in the quasi-degenerate neutrino mass spectrum is 100 times\nsmaller than the ones in the inverse-hierarchical and the hierarchical neutrino\nspectra. We emphasize that the magnitude of $U_{e3}$ is one of important\ningredients to predict BR($\\mu \\to e +\\gamma $). The effect of the deviation\nfrom the complete-degenerate right-handed Majorana neutrino masses are also\nestimated. Furtheremore, we examine the $S_{3\\sL}\\times S_{3\\sR}$ model, which\ngives the quasi-degenerate neutrino masses, and the Shafi-Tavartkiladze model,\nwhich gives the inverse-hierarchical neutrino masses. Both predicted branching\nratios of $\\mu\\to e+\\gamma$ are smaller than the experimantal bound.", "category": "hep-ph" } ]