[ { "text": "Study of a narrow pi+ pi- peak at about 755 MeV/c^2 in bar-p n --> 2 pi+\n 3 pi- annihilation at rest: A narrow peak in the pi+ pi- mass distribution was seen by the Rome-Syracuse\nCollaboration in bar-p n --> 2 pi+ 3 pi- annihilation at rest 39 years ago. The\nreanalysis of this peak finds a mass of 757.4 +- 2.6 MeV/c^2 and a width\nslightly narrower than the experimental resolution. The evidence of the peak is\n5.2 standard deviations. This state is generated in (12.4 +- 2.4)% of the bar-p\nn --> 2 pi+ 3 pi- annihilations at rest. No spin analysis is possible with the\nstatistics of the experiment.", "category": "hep-ex" }, { "text": "Search for Photon-Photon Elastic Scattering in the X-ray Region: We report the first results of a search for real photon-photon scattering\nusing X rays. A novel system is developed to split and collide X-ray pulses by\napplying interferometric techniques. A total of $6.5\\times10^{5}$ pulses (each\ncontaining about $10^{11}$ photons) from an X-ray Free-Electron Laser are\ninjected into the system. No scattered events are observed, and an upper limit\nof $1.7\\times 10^{-24}$ ${\\rm m^{2}}$ (95% C.L.) is obtained on the\nphoton-photon elastic scattering cross section at 6.5 keV.", "category": "hep-ex" }, { "text": "Ultimate sensitivity on gamma/phi3 from B->DK: Measurement of the CKM phase gamma in B->DK decays can be potentially\nperformed with high precision due to low theoretical uncertainties. However,\nthe precision measurement requires very large experimental samples of B decays.\nThis report covers prospects for gamma measurement at the future e+e-\nfacilities and upgraded LHCb detector.", "category": "hep-ex" }, { "text": "Search for b--> u transitions in B- -> [K+pi-pi0]_D K-: We search for decays of a B meson into a neutral D meson and a kaon, with the\nD meson decaying into K+pi-pi0. This final state can be reached through the b\n--> c transition B- -> D0K- followed by the doubly Cabibbo-suppressed D0 -->\nK+pi-pi0, or the b --> u transition B- --> D0bar K- followed by the\nCabibbo-favored D0bar --> K+ pi-pi0. The interference of these two amplitudes\nis sensitive to the angle gamma of the unitarity triangle. We present\npreliminary results based on 226 10^{6} e+e- --> Y(4s) --> BBbar events\ncollected with the BABAR detector at SLAC. We find no significant evidence for\nthese decays and we set a limit R_ADS =(BR(B- -->[K+pi-pi0]_D K-)+ BR(B- -->\n[K-pi+pi0]_D K+))/(BR(B- -->[K-pi+pi0]_D K-)+ BR(B- --> [K+pi-pi0]_D K+))<0.039\nat 95% confidence level, which we translate with a Bayesian approach into r_B =\n|A(B- --> D0bar K-)|/|A(B- --> D0bar K-)| < 0.185 at 95% confidence level.", "category": "hep-ex" }, { "text": "New New-Phenomena Results from Dzero: We have searched for diphoton events (\\ggmet) with large missing transverse\nmomentum, $\\gamma\\rlap{\\kern0.25em/}E_T$ events (\\gmetjj) with two or more\njets, and diphoton events ($\\gamma\\gamma$) with high transverse energies in\n$p\\bar p$ collisions at $\\sqrt{s} = 1.8$ TeV using approximately 100~pb$^{-1}$\nof data collected with the D\\O detector at the Fermilab Tevatron in 1992--1996.\nNo excess of events beyond the expected backgrounds is observed. The null\nresults are interpreted in supersymmetric models with a dominant\n$\\tilde\\chi^0_2\\to\\gamma\\tilde\\chi^0_1$ decay and in terms of Dirac pointlike\nmonopole production.", "category": "hep-ex" }, { "text": "Determination of electroweak parameters in polarised deep-inelastic\n scattering at HERA: The parameters of the electroweak theory are determined in a combined\nelectroweak and QCD analysis using all deep-inelastic $e^+p$ and $e^-p$ neutral\ncurrent and charged current scattering cross sections published by the H1\nCollaboration, including data with longitudinally polarised lepton beams.\nVarious fits to Standard Model parameters in the on-shell scheme are performed.\nThe mass of the $W$ boson is determined as $m(W)=80.520\\pm 0.115$ GeV. The\naxial-vector and vector couplings of the light quarks to the $Z$ boson are also\ndetermined. Both results improve the precision of previous H1 determinations\nbased on HERA-I data by about a factor of two. Possible scale dependence of the\nweak coupling parameters in both neutral and charged current interactions\nbeyond the Standard Model is also studied. All results are found to be\nconsistent with the Standard Model expectations.", "category": "hep-ex" }, { "text": "Measurement of the forward charged particle pseudorapidity density in pp\n collisions at sqrt{s} = 7 TeV with the TOTEM experiment: The TOTEM experiment has measured the charged particle pseudorapidity density\ndN_{ch}/deta in pp collisions at sqrt{s} = 7 TeV for 5.3<|eta|<6.4 in events\nwith at least one charged particle with transverse momentum above 40 MeV/c in\nthis pseudorapidity range. This extends the analogous measurement performed by\nthe other LHC experiments to the previously unexplored forward eta region. The\nmeasurement refers to more than 99% of non-diffractive processes and to single\nand double diffractive processes with diffractive masses above ~3.4 GeV/c^2,\ncorresponding to about 95% of the total inelastic cross-section. The\ndN_{ch}/deta has been found to decrease with |eta|, from 3.84 pm 0.01(stat) pm\n0.37(syst) at |eta| = 5.375 to 2.38 pm 0.01(stat) pm 0.21(syst) at |eta| =\n6.375. Several MC generators have been compared to data; none of them has been\nfound to fully describe the measurement.", "category": "hep-ex" }, { "text": "Prospect for precision measurements of MW+ -MW- & MW at the LHC:\n Shortcuts revisited: The claim that the W boson mass might be measured at the LHC with a precision\nof O(10 MeV) is critically reviewed. It is argued that such a precision cannot\nbe achieved, unless a dedicated measurement program, specific to the LHC is\npursued. We propose such a program. Its main target is to significantly improve\nthe experimental control of the relative polarisation of the W+, W- and Z\nbosons. We propose to achieve this goal either by running dedicated isoscalar\nbeams at the LHC or by running, in parallel to the standard p-p collision\nprogram, a dedicated muon scattering \"LHC-support-experiment\" at the CERN SPS.\nOne of these auxiliary measurements is necessary for the \"precision measurement\nprogram\" at the LHC, but not sufficient. It must be followed by dedicated\nmeasurement strategies which are robust with respect to both the systematic\nmeasurement uncertainties and to the perturbative and non-perturbative QCD\neffects. We propose such strategies and evaluate their precision. At the LHC,\ncontrary to the Tevatron case, both the masses of the W+ and of the W- bosons\nmust be measured with high precision. In this context, we propose and evaluate\nLHC dedicated strategies to measure the difference of the masses of the W+ and\nW- bosons and of the absolute mass of the W boson assuming both masses are\nequal. We show how one can overcome the obstacles in measuring the masses of W+\nand W- to a precision of 10 MeV. We present a detailed evaluation of the\nprecision of the proposed methods based on the studies of a large, O(10^11),\nsample of simulated W and Z production events.", "category": "hep-ex" }, { "text": "Search for Proton Decay into Muon plus Neutral Kaon in Super-Kamiokande\n I, II, and III: We have searched for proton into muon plus neutral kaon using data from a\n91.7 kiloton-year exposure of Super-Kamiokande-I, a 49.2 kiloton-year exposure\nof Super-Kamiokande-II, and a 31.9 kiloton-year exposure of\nSuper-Kamiokande-III. The number of candidate events in the data was consistent\nwith the atmospheric neutrino background expectation and no evidence for proton\ndecay in this mode was found. We set a partial lifetime lower limit of\n1.6x10^33 years at the 90% confidence level.", "category": "hep-ex" }, { "text": "Search for WH production with a light Higgs boson decaying to prompt\n electron-jets in proton-proton collisions at sqrt(s)=7 TeV with the ATLAS\n detector: A search is performed for WH production with a light Higgs boson decaying to\nhidden-sector particles resulting in clusters of collimated electrons, known as\nelectron-jets. The search is performed with 2.04 fb-1 of data collected in 2011\nwith the ATLAS detector at the LHC in proton-proton collisions at sqrt(s)=7\nTeV. One event satisfying the signal selection criteria is observed, which is\nconsistent with the expected background rate. Limits on the product of the WH\nproduction cross section and the branching ratio of a Higgs boson decaying to\nprompt electron-jets are calculated as a function of a Higgs boson mass in the\nrange from 100 GeV to 140 GeV.", "category": "hep-ex" }, { "text": "Recent progress on the study of the charmoniumlike states: In this article, we review the recent experimental studies on the\ncharmoniumlike states, mainly from the e+e- annihilation experiments BESIII,\nBelle, BaBar, and CLEO-c, and the hadron collider experiment LHCb. We discuss\nthe results on the X(3872), the vector Y states [Y(4008), Y(4660), and those in\ne+e- to pi+pi-h_c], and the charged charmoniumlike Z_c^- states.", "category": "hep-ex" }, { "text": "New Results from the Muon g-2 Experiment: The Muon g-2 collaboration has measured the anomalous magnetic g value, a =\n(g-2)/2, of the positive muon with an unprecedented uncertainty of 0.7 parts\nper million. The result, based on data collected in the year 2000 at Brookhaven\nNational Laboratory, is in good agreement with the preceding data. The\nmeasurement tests standard model theory, which at the level of the current\nexperimental uncertainty involves quantum electrodynamics, quantum\nchromodynamics, and electroweak interaction in a significant way.", "category": "hep-ex" }, { "text": "Search for Dark Photons in $\u03b3\u03b3\\rightarrow e^+e^-$ at RHIC: The fundamental nature of Dark Matter remains one of the major mysteries of\nmodern physics. Some models postulate the existence of a massive gauge boson, a\n\"dark photon\" ($A^\\prime$), that may allow Dark Matter particles to interact\nwith Standard Model particles. Ultra-relativistic heavy-ion collisions produce\nhighly Lorentz-contracted electromagnetic fields with sufficient energy density\nto potentially manifest as light dark photons. We report limits on dark photon\nparameters via a search for anomalous production of $e^+e^-$ pairs in $\\gamma\nA^\\prime$ and $A^\\prime A^\\prime$ fusion from ultra-peripheral\n$\\rm{Au}+\\rm{Au}$ collisions. This study utilizes measurements of the\nBreit-Wheeler process ($\\gamma\\gamma \\rightarrow e^+e^-$) carried out by STAR,\nspecifically making use of polarization-dependent final-state azimuthal\nasymmetries in $e^+e^-$ pairs. These limits are informative for future searches\nin the ultra-peripheral heavy-ion collisions and to constrain future\ntheoretical developments of the dark photon mechanism.", "category": "hep-ex" }, { "text": "Deep Underground Neutrino Experiment (DUNE), Far Detector Technical\n Design Report, Volume II: DUNE Physics: The preponderance of matter over antimatter in the early universe, the\ndynamics of the supernovae that produced the heavy elements necessary for life,\nand whether protons eventually decay -- these mysteries at the forefront of\nparticle physics and astrophysics are key to understanding the early evolution\nof our universe, its current state, and its eventual fate. DUNE is an\ninternational world-class experiment dedicated to addressing these questions as\nit searches for leptonic charge-parity symmetry violation, stands ready to\ncapture supernova neutrino bursts, and seeks to observe nucleon decay as a\nsignature of a grand unified theory underlying the standard model.\n The DUNE far detector technical design report (TDR) describes the DUNE\nphysics program and the technical designs of the single- and dual-phase DUNE\nliquid argon TPC far detector modules. Volume II of this TDR, DUNE Physics,\ndescribes the array of identified scientific opportunities and key goals.\nCrucially, we also report our best current understanding of the capability of\nDUNE to realize these goals, along with the detailed arguments and\ninvestigations on which this understanding is based.\n This TDR volume documents the scientific basis underlying the conception and\ndesign of the LBNF/DUNE experimental configurations. As a result, the\ndescription of DUNE's experimental capabilities constitutes the bulk of the\ndocument. Key linkages between requirements for successful execution of the\nphysics program and primary specifications of the experimental configurations\nare drawn and summarized.\n This document also serves a wider purpose as a statement on the scientific\npotential of DUNE as a central component within a global program of frontier\ntheoretical and experimental particle physics research. Thus, the presentation\nalso aims to serve as a resource for the particle physics community at large.", "category": "hep-ex" }, { "text": "Open Heavy Flavor Production in Deeply Inelastic ep Scattering at HERA: Recent results on inclusive D^0 and D^{*+-} production in deeply inelastic ep\nscattering at sqrt(s)=301 GeV are summarized. The data have been collected by\nthe H1 and ZEUS experiments at HERA. The total and the differential cross\nsections are discussed in the framework of LO and NLO QCD predictions. The data\nexhibit clear evidence for boson gluon fusion dominating open heavy flavor\nproduction in the kinematic range currently explored at HERA. The measurements\nof F_2^{cc}(x,Q^2) at small Bjorken x are presented. The prospects for future\nanalyses of open charm and beauty production including detector upgrades and\nanticipated high luminosities are investigated.", "category": "hep-ex" }, { "text": "On the Energy Spectrum of Cosmogenic Neutrons: The processes of the generation of cosmogenic neutrons (cg-neutrons)\nunderground are considered. The neutrons produced by cosmic-ray muons in their\ninteractions with matter are called cosmogenic. Deep-inelastic\n${\\pi}A$-collisions of pions in muon-induced hadronic showers are mainly their\nsource at energies above 30 MeV. The characteristics of the energy spectrum for\nthe generation of cg-neutrons have been determined by invoking the additive\nquark model of deep-inelastic soft processes and the mechanism for the\ninteractions of high-energy nucleons in a nucleus. The three-component shape of\nthe spectrum is explained, and the energy of the \"knee\" in the spectrum has\nbeen found to depend on the mass number $A$. The peculiarities of\ndeep-inelastic ${\\pi}A$-scattering lead to the conclusion that the spectrum of\ncg-neutrons steepens sharply at energies above 1 GeV. The calculated\nquantitative characteristics of the spectrum are compared with those obtained\nin measurements.", "category": "hep-ex" }, { "text": "Recent QCD results from OPAL: Some recent QCD results from the OPAL Collaboration are summarized. In\nparticular: a test of color reconnection models and a search for glueballs\nusing gluon jets with a rapidity gap; a study of unbiased gluon jet properties\nusing a new technique called jet boost algorithm; a measurement of the strong\ncoupling constant from radiative events.", "category": "hep-ex" }, { "text": "Results and Future Prospects for Muon (g-2): Spin physics had its beginnings in the famous experiments of Stern and\nGerlach, which eventually resulted in the postulation of spin by Goudsmit and\nUhlenbeck. The Stern-Gerlach experiment told us that the $g$-value of the\nelectron was 2, but we now know that because of radiative corrections, the\n$g$-value of the leptons is slightly greater than 2, the lowest-order\ncontribution being $\\alpha/\\pi$, where $\\alpha$ is the fine-structure constant.\nMeasurements of the magnetic dipole moments of the electron and muon have\nplayed a major role in our understanding of QED and of the standard model. In\nthis talk I discuss the progress on measurements and theory of the magnetic\ndipole moment of the muon.", "category": "hep-ex" }, { "text": "Neutral pion photoproduction off protons in the energy range 0.3 GeV <\n E(gamma) < 3 GeV: Single pi0 photoproduction has been studied with the CB-ELSA experiment at\nBonn using tagged photon energies between 0.3 and 3.0 GeV. The experimental\nsetup covers a very large solid angle of about 98% of 4 pi. Differential cross\nsections (d sigma)/(d Omega) have been measured. Complicated structures in the\nangular distributions indicate a variety of different resonances being produced\nin the s channel intermediate state gamma p --> N* (Delta*) --> p pi0. A\ncombined analysis including the data presented in this letter along with other\ndata sets reveals contributions from known resonances and evidence for a new\nresonance N(2070)D15.", "category": "hep-ex" }, { "text": "Search for pseudoscalar bosons decaying into $e^+e^-$ pairs in the NA64\n experiment at the CERN SPS: We report the results of a search for a light pseudoscalar particle $a$ that\ncouples to electrons and decays to $e^+e^-$ performed using the high-energy\nCERN SPS H4 electron beam. If such pseudoscalar with a mass $\\simeq 17$ MeV\nexists, it could explain the ATOMKI anomaly. We used the NA64 data samples\ncollected in the \"visible mode\" configuration with total statistics\ncorresponding to $8.4\\times 10^{10}$ electrons on target (EOT) in 2017 and\n2018. In order to increase sensitivity to small coupling parameter $\\epsilon$\nwe used also the data collected in 2016-2018 in the \"invisible mode\"\nconfiguration of NA64 with a total statistics corresponding to $2.84\\times\n10^{11}$ EOT. A thorough analysis of both these data samples in the sense of\nbackground and efficiency estimations was already performed and reported in our\nprevious papers devoted to the search for light vector particles and axion-like\nparticles (ALP). In this work we recalculate the signal yields, which are\ndifferent due to different cross section and life time of a pseudoscalar\nparticle $a$, and perform a new statistical analysis. As a result, the region\nof the two dimensional parameter space $m_a - \\epsilon$ in the mass range from\n1 to 17.1 MeV is excluded. At the mass of the ATOMKI anomaly the values of\n$\\epsilon$ in the range $2.1 \\times 10^{-4} < \\epsilon < 3.2 \\times 10^{-4}$\nare excluded.", "category": "hep-ex" }, { "text": "Observation of Hyperfine Transitions in Trapped Ground-State\n Antihydrogen: This paper discusses the first observation of stimulated magnetic resonance\ntransitions between the hyperfine levels of trapped ground state atomic\nantihydrogen, confirming its presence in the ALPHA apparatus. Our observations\nshow that these transitions are consistent with the values in hydrogen to\nwithin 4~parts~in~$10^3$. Simulations of the trapped antiatoms in a microwave\nfield are consistent with our measurements.", "category": "hep-ex" }, { "text": "Determination of the strangeness content of light-flavour isoscalars\n from their production rates in hadronic Z decays at LEP: A new phenomenological approach is suggested for determining the strangeness\ncontent of light-flavour isoscalars. This approach is based on phenomenological\nlaws of hadron production related to the spin, isospin, strangeness content and\nmass of the particles. From the total production rates per hadronic Z decay of\nall light-flavour hadrons, measured so far at LEP, the values of the\nnonstrange-strange mixing angles are found to be |\\phi_P| = 42.3^{\\circ} \\pm\n3.5^{\\circ}, |\\phi_V| = 10^{\\circ} \\pm 8^{\\circ}, |\\phi_T| = 16^{\\circ} \\pm\n11^{\\circ} and |\\phi_S| = 13^{\\circ} \\pm 9^{\\circ}. Our results on the\n\\eta-\\eta^{\\prime}, \\omega-\\phi and f_2-f_2^{\\prime} isoscalar mixing are\nconsistent with the present experimental evidence. The strangeness content\nobtained for the f_0(980) scalar/isoscalar is not consistent with the values\nsupported by recent model studies and is discussed further in the framework of\nour approach and the K-matrix analysis.", "category": "hep-ex" }, { "text": "Neural-network-driven proton decay sensitivity in the $p\\rightarrow\n \\bar\u03bd K^{+}$ channel using large liquid argon time projection chambers: We report on an updated sensitivity for proton decay via $p \\rightarrow\n\\bar{\\nu} K^+ $ at large, dual phase liquid argon time projection chambers (LAr\nTPCs). Our work builds on a previous study in which several nucleon decay\nchannels have been simulated and analyzed [arXiv:hep-ph/0701101]. At the time\nseveral assumptions were needed to be made on the detector and the backgrounds.\nSince then, the community has made progress in defining these, and the\ncomputing power available enables us to fully simulate and reconstruct large\nsamples in order to perform a better estimate of the sensitivity to proton\ndecay. In this work, we examine the benchmark channel $p\\rightarrow \\bar{\\nu}\nK^{+}$, which was previously found to be one of the cleanest channels. Using an\nimproved neutrino event generator and a fully simulated LAr TPC detector\nresponse combined with a dedicated neural network for kaon identification, we\ndemonstrate that a lifetime sensitivity of $ \\tau / \\text{Br} \\left( p\n\\rightarrow \\bar{\\nu} K^+ \\right) > 7 \\times 10^{34} \\, \\text{years}$ at $90 \\,\n\\%$ confidence level can be reached at an exposure of $1 \\, \\text{megaton}\n\\cdot \\text{year}$ in quasi-background-free conditions, confirming the\nsuperiority of the LAr TPC over other technologies to address the challenging\nproton decay modes.", "category": "hep-ex" }, { "text": "Search for supersymmetry in pp collisions at sqrt(s) = 13 TeV in the\n single-lepton final state using the sum of masses of large-radius jets: Results are reported from a search for supersymmetric particles in\nproton-proton collisions in the final state with a single, high transverse\nmomentum lepton; multiple jets, including at least one b-tagged jet; and large\nmissing transverse momentum. The data sample corresponds to an integrated\nluminosity of 2.3 inverse femtobarns at sqrt(s) = 13 TeV, recorded by the CMS\nexperiment at the LHC. The search focuses on processes leading to high jet\nmultiplicities, such as gluino pair production with gluinos to t t-bar\nneutralino[1]. The quantity M[J], defined as the sum of the masses of the\nlarge-radius jets in the event, is used in conjunction with other kinematic\nvariables to provide discrimination between signal and background and as a key\npart of the background estimation method. The observed event yields in the\nsignal regions in data are consistent with those expected for standard model\nbackgrounds, estimated from control regions in data. Exclusion limits are\nobtained for a simplified model corresponding to gluino pair production with\nthree-body decays into top quarks and neutralinos. Gluinos with a mass below\n1600 GeV are excluded at a 95% confidence level for scenarios with low\nneutralino[1] mass, and neutralinos with a mass below 800 GeV are excluded for\na gluino mass of about 1300 GeV. For models with two-body gluino decays\nproducing on-shell top squarks, the excluded region is only weakly sensitive to\nthe top squark mass.", "category": "hep-ex" }, { "text": "$J/\u03c8$ and $\u03c8(2S)$ production at forward rapidity in $p$+$p$\n collisions at $\\sqrt{s}=510$ GeV: The PHENIX experiment at the Relativistic Heavy Ion Collider has measured the\ndifferential cross section, mean transverse momentum, mean transverse momentum\nsquared of inclusive $J/\\psi$ and cross-section ratio of $\\psi(2S)$ to $J/\\psi$\nat forward rapidity in \\pp collisions at \\sqrts = 510 GeV via the dimuon decay\nchannel. Comparison is made to inclusive $J/\\psi$ cross sections measured at\n\\sqrts = 200 GeV and 2.76--13 TeV. The result is also compared to leading-order\nnonrelativistic QCD calculations coupled to a color-glass-condensate\ndescription of the low-$x$ gluons in the proton at low transverse momentum\n($p_T$) and to next-to-leading order nonrelativistic QCD calculations for the\nrest of the $p_T$ range. These calculations overestimate the data at low $p_T$.\nWhile consistent with the data within uncertainties above $\\approx3$ GeV/$c$,\nthe calculations are systematically below the data. The total cross section\ntimes the branching ratio is BR $d\\sigma^{J/\\psi}_{pp}/dy (1.2<|y|<2.2,\n0200$ GeV is significantly\nhigher than current predictions based on O($\\alpha_s^3$) perturbative QCD\ncalculations. Various possible explanations for the high-$E_T$ excess are\ndiscussed.", "category": "hep-ex" }, { "text": "Higher-order multipole amplitudes in charmonium radiative transitions: Using 24 million $\\psi' \\equiv \\psi(2S)$ decays in CLEO-c, we have searched\nfor higher multipole admixtures in electric-dipole-dominated radiative\ntransitions in charmonia. We find good agreement between our data and\ntheoretical predictions for magnetic quadrupole (M2) amplitudes in the\ntransitions $\\psi' \\to \\gamma \\chi_{c1,2}$ and $\\chi_{c1,2} \\to \\gamma J/\\psi$,\nin striking contrast to some previous measurements. Let $b_2^J$ and $a_2^J$\ndenote the normalized M2 amplitudes in the respective aforementioned decays,\nwhere the superscript $J$ refers to the angular momentum of the $\\chi_{cJ}$. By\nperforming unbinned maximum likelihood fits to full five-parameter angular\ndistributions, we determine the ratios $a_2^{J=1}/a_2^{J=2} =\n0.67^{+0.19}_{-0.13}$ and $a_2^{J=1}/b_2^{J=1} = -2.27^{+0.57}_{-0.99}$, where\nthe theoretical predictions are independent of the charmed quark magnetic\nmoment and are $a_2^{J=1}/a_2^{J=2} = 0.676 \\pm 0.071$ and $a_2^{J=1}/b_2^{J=1}\n= -2.27 \\pm 0.16$.", "category": "hep-ex" }, { "text": "First Jet and High $\\pT$ Measuerements with the ALICE Experiment at the\n LHC: The Large Hadron Collider at CERN currently provides p$+$p collisions at\ncenter of mass energies of $\\sqrt{s} = 7$~TeV, which allow to study high $\\pT$\nparticle production and jet properties in a new energy regime. For a clear\ninterpretation and the quantification of the medium influence in heavy-ion\ncollisions on high $\\pT$ observables a detailed understanding of these\nelementary reactions is essential. We present first results on the observation\nof jet-like properties with the ALICE experiment and discuss the performance of\njet reconstruction in the first year of data taking.", "category": "hep-ex" }, { "text": "LHC analysis-specific datasets with Generative Adversarial Networks: Using generative adversarial networks (GANs), we investigate the possibility\nof creating large amounts of analysis-specific simulated LHC events at limited\ncomputing cost. This kind of generative model is analysis specific in the sense\nthat it directly generates the high-level features used in the last stage of a\ngiven physics analyses, learning the N-dimensional distribution of relevant\nfeatures in the context of a specific analysis selection. We apply this idea to\nthe generation of muon four-momenta in $Z \\to \\mu\\mu$ events at the LHC. We\nhighlight how use-case specific issues emerge when the distributions of the\nconsidered quantities exhibit particular features. We show how substantial\nperformance improvements and convergence speed-up can be obtained by including\nregression terms in the loss function of the generator. We develop an objective\ncriterion to assess the geenrator performance in a quantitative way. With\nfurther development, a generalization of this approach could substantially\nreduce the needed amount of centrally produced fully simulated events in large\nparticle physics experiments.", "category": "hep-ex" }, { "text": "Future Prospects at Electron-Positron Machines: This review will present the future prospects for physics at\nelectron-positron colliders running near the Upsilon(4S) as well as at the\ncharm and tau thresholds. It includes a review of the Belle II and SuperB\nprojects. Also reviewed are the plans for BES III, which operates near the\ncharm threshold at the IHEP BEPC machine in Bejing and the status of the Super\nCharm/Tau Factory proposed for the Budker Institute for Nuclear Physics (BINP)\nin Novosibirsk.", "category": "hep-ex" }, { "text": "Measurement of the $W \\to e \u03bd$ and $Z/\u03b3^* \\to e^+e^-$ Production\n Cross Sections at Mid-rapidity in Proton-Proton Collisions at $\\sqrt{s}$ =\n 500 GeV: We report measurements of the charge-separated $W^{+(-)} \\to e^{+(-)} +\n\\nu_e(\\bar{\\nu}_e)$ and $Z/\\gamma^* \\to e^+e^-$ production cross sections at\nmid-rapidity in proton-proton collisions at $\\sqrt{s}$ = 500 GeV. These results\nare based on 13.2 pb$^{-1}$ of data recorded in 2009 by the STAR detector at\nRHIC. Production cross sections for W bosons that decay via the $e \\nu$ channel\nwere measured to be $\\sigma(pp \\to W^+ X) \\cdot BR(W^+ \\to e^+ \\nu_e)$ = 117.3\n\\pm 5.9(stat) \\pm 6.2(syst) \\pm 15.2(lumi) pb, and $\\sigma(pp \\to W^- X) \\cdot\nBR(W^- \\to e^- \\bar{\\nu}_e)$ = 43.3 \\pm 4.6(stat) \\pm 3.4(syst) \\pm 5.6(lumi)\npb. For $Z/\\gamma^*$ production, $\\sigma(pp \\to Z/\\gamma^* X) \\cdot\nBR(Z/\\gamma^* \\to e^+ e^-)$ = 7.7 \\pm 2.1(stat) $^{+0.5}_{-0.9}$(syst) \\pm\n1.0(lumi) pb for di-lepton invariant masses $m_{e^+e^-}$ between 70 and 110\nGeV/$c^2$. First measurements of the W cross section ratio, $\\sigma(pp \\to W^+\nX) / \\sigma(pp \\to W^- X)$, at $\\sqrt{s}$ = 500 GeV are also reported.\nTheoretical predictions, calculated using recent parton distribution functions,\nare found to agree with the measured cross sections.", "category": "hep-ex" }, { "text": "The GENIUS Project - Background and technical studies: The potential of GENIUS as a dark matter detector is discussed. A study was\nperformed to demonstrate the good behaviour of the proposed detector design of\nnaked HPGe-crystals in liquid nitrogen. The expected background components were\nsimulated and are discussed in some detail.With the obtained background GENIUS\ncould cover a large part of the favoured MSSM parameter-space.", "category": "hep-ex" }, { "text": "J/$\u03c8$ and $\u03c8$(2S) production in p-Pb collisions at\n $\\sqrt{s_{NN}}=\\mathrm{5.02}$ TeV with ALICE at the LHC: The ALICE Collaboration has studied the inclusive J/$\\psi$ and\n$\\psi(\\mathrm{2S})$ production in p-Pb collisions at $\\sqrt{s_{NN}}$ = 5.02\nTeV, at the CERN LHC. The J/$\\psi$ measurement is performed in the\n$\\mu^{+}\\mu^{-}$ and in the $e^{+}e^{-}$ decay channels, down to zero\n$p_{\\mathrm{T}}$. The results are in fair agreement with theoretical\npredictions. The $\\psi(\\mathrm{2S})$ measurement has also been performed. In\nparticular, a smaller $\\psi(\\mathrm{2S})$ nuclear modification factor, with\nrespect to the J$/\\psi$ one, has been observed.", "category": "hep-ex" }, { "text": "Measurement of the $K^+\\to\u03c0^+\u03b3\u03b3$ decay: A sample of 3984 candidates of the $K^+\\to\\pi^+\\gamma\\gamma$ decay, with an\nestimated background of $291\\pm14$ events, was collected by the NA62 experiment\nat CERN during 2017-2018. In order to describe the observed di-photon mass\nspectrum, the next-to-leading order contribution in chiral perturbation theory\nwas found to be necessary. The decay branching ratio in the full kinematic\nrange is measured to be $(9.61\\pm0.17)\\times10^{-7}$. The first search for\nproduction and prompt decay of an axion-like particle with gluon coupling in\nthe process $K^+\\to\\pi^+a$, $a\\to\\gamma\\gamma$ is also reported.", "category": "hep-ex" }, { "text": "Search for new physics in final states with an energetic jet or a\n hadronically decaying W or Z boson and transverse momentum imbalance at\n $\\sqrt{s} = $ 13 TeV: A search for new physics using events containing an imbalance in transverse\nmomentum and one or more energetic jets arising from initial-state radiation or\nthe hadronic decay of W or Z bosons is presented. A data sample of\nproton-proton collisions at $\\sqrt{s} = $ 13 TeV, collected with the CMS\ndetector at the LHC and corresponding to an integrated luminosity of 35.9\nfb$^{-1}$, is used. The observed data are found to be in agreement with the\nexpectation from standard model processes. The results are interpreted as\nlimits on the dark matter production cross section in simplified models with\nvector, axial-vector, scalar, and pseudoscalar mediators. Interpretations in\nthe context of fermion portal and nonthermal dark matter models are also\nprovided. In addition, the results are interpreted in terms of invisible decays\nof the Higgs boson and set stringent limits on the fundamental Planck scale in\nthe Arkani-Hamed, Dimopoulos, and Dvali model with large extra spatial\ndimensions.", "category": "hep-ex" }, { "text": "Search for the Standard Model Higgs Boson at LEP: The four LEP collaborations, ALEPH, DELPHI, L3 and OPAL, have collected 2465\npb-1 of e+e- collision data at energies between 189 and 209 GeV, of which 542\npb-1 were collected above 206 GeV. Searches for the Standard Model Higgs boson\nhave been performed by each of the LEP collaborations. Their data have been\ncombined and examined for their consistency with the Standard Model background\nand various Standard Model Higgs boson mass hypotheses. A lower bound of 114.1\nGeV has been obtained at the 95% confidence level for the mass of the Higgs\nboson. The likelihood analysis shows a preference for a Higgs boson with a mass\nof 115.6 GeV. At this mass, the probability for the background to generate the\nobserved effect is 3.4%.", "category": "hep-ex" }, { "text": "Searches for New Neutral Gauge Bosons and Leptoquarks at the Tevatron: This contribution reports on some of the most recent searches for new heavy\nneutral bosons and leptoquarks performed at the Tevatron experiments.", "category": "hep-ex" }, { "text": "Experimental investigation of transverse spin asymmetries in muon-p\n SIDIS processes: Collins asymmetries: The COMPASS Collaboration at CERN has measured the transverse spin azimuthal\nasymmetry of charged hadrons produced in semi-inclusive deep inelastic\nscattering using a 160 GeV positive muon beam and a transversely polarised NH_3\ntarget. The Collins asymmetry of the proton was extracted in the Bjorken x\nrange 0.003pi0e+e- and KS->pi0mu+mu- have\nbeen made by the NA48/1 collaboration at the CERN SPS accelerator. From high\nintensity KS data collected during the 2002 run, clean signals of 7 KS->pi0e+e-\nevents and 6 KS->pi0mu+mu- events were observed, giving branching ratio\nmeasurements of BR(KS->pi0e+e-) = 5.8 +2.9 -2.4 x 10^-9 and BR(KS->pi0mu+mu-) =\n2.9 +1.5 -1.2 x 10^-9. These results constrain the indirect CP violating\ncomponent of the corresponding KL decays. Other recent results from NA48 are\nalso presented.", "category": "hep-ex" }, { "text": "Prospects for e+e- physics at Frascati between the phi and the psi: We present a detailed study, done in the framework of the INFN 2006 Roadmap,\nof the prospects for e+e- physics at the Frascati National Laboratories. The\nphysics case for an e+e- collider running at high luminosity at the phi\nresonance energy and also reaching a maximum center of mass energy of 2.5 GeV\nis discussed, together with the specific aspects of a very high luminosity\ntau-charm factory. Subjects connected to Kaon decay physics are not discussed\nhere, being part of another INFN Roadmap working group. The significance of the\nproject and the impact on INFN are also discussed. All the documentation\nrelated to the activities of the working group can be found in\nhttp://www.roma1.infn.it/people/bini/roadmap.html.", "category": "hep-ex" }, { "text": "Observation of $D^0\\to K_1(1270)^- e^+\u03bd_e$: Using 2.93 fb$^{-1}$ of $e^+e^-$ collision data taken with the BESIII\ndetector at a center-of-mass energy of 3.773 $\\rm \\,GeV$, the observation of\nthe $D^0\\to K_1(1270)^- e^+\\nu_e$ semileptonic decay is presented. The\nstatistical significance of the decay $D^0\\to K_1(1270)^- e^+\\nu_e$ is greater\nthan $10\\sigma$. The branching fraction of $D^0\\to K_1(1270)^- e^+\\nu_e$ is\nmeasured to be $(1.09\\pm0.13^{+0.09}_{-0.16} \\pm 0.12)\\times10^{-3}$. Here, the\nfirst uncertainty is statistical, the second is systematic, and the third\noriginates from the assumed branching fraction of $K_1(1270)^- \\rightarrow\nK^-\\pi^+\\pi^-$. The fraction of longitudinal polarization in $D^0\\to\nK_1(1270)^- e^+\\nu_e$ is determined for the first time to be $0.50\\pm0.19_{\\rm\nstat}\\pm0.08_{\\rm syst}$.", "category": "hep-ex" }, { "text": "Production of pi+, pi-, K+, K-, p and p-bar in Light (uds), c and b Jets\n from Z0 Decays: We present improved measurements of the differential production rates of\nstable charged particles in hadronic Z0 decays, and of charged pions, kaons and\nprotons identified over a wide momentum range using the SLD Cherenkov Ring\nImaging Detector. In addition to flavor-inclusive Z0 decays, measurements are\nmade for Z0 decays into light (u, d, s), c and b primary flavors, selected\nusing the upgraded Vertex Detector. Large differences between the flavors are\nobserved that are qualitatively consistent with expectations based upon\npreviously measured production and decay properties of heavy hadrons. These\nresults are used to test the predictions of QCD in the Modified Leading\nLogarithm Approximation, with the ansatz of Local Parton-Hadron Duality, and\nthe predictions of three models of the hadronization process. The light-flavor\nresults provide improved tests of these predictions, as they do not include the\ncontribution of heavy-hadron production and decay; the heavy-flavor results\nprovide complementary model tests. In addition we have compared hadron and\nantihadron production in light quark (as opposed to antiquark) jets.\nDifferences are observed at high momentum for all three charged hadron species,\nproviding direct probes of leading particle effects, and stringent constraints\non models.", "category": "hep-ex" }, { "text": "Search for New Physics at CDF: We present the current status of the search for new physics at CDF, using\nintegrated luminosity up to 3.2 fb-1. We cover searches for supersymmetry,\nextra dimensions, new heavy bosons, and generic dilepton resonances.", "category": "hep-ex" }, { "text": "Search for a W' Boson via the Decay Mode W' -> mu nu in 1.8 TeV p-pbar\n Collisions: We report the results of a search for a W' boson produced in p-pbar\ncollisions at a center-of-mass energy of 1.8 TeV using a 107 pb-1 data sample\nrecorded by the Collider Detector at Fermilab. We consider the decay channel W'\n-> mu nu and search for anomalous production of high transverse mass mu-nu\nlepton pairs. We observe no excess of events above background and set limits on\nthe rate of W' boson production and decay relative to Standard Model W boson\nproduction and decay using a fit of the transverse mass distribution observed.\nIf we assume Standard Model strength couplings of the W' boson to quark and\nlepton pairs, we exclude a W' boson with invariant mass less than 660 GeV/c**2\nat 95% confidence level.", "category": "hep-ex" }, { "text": "Measurement of the top-quark mass in t t-bar events with lepton+jets\n final states in pp collisions at sqrt(s) = 7 TeV: The mass of the top quark is measured using a sample of t t-bar candidate\nevents with one electron or muon and at least four jets in the final state,\ncollected by CMS in pp collisions at sqrt(s) = 7 TeV at the LHC. A total of\n5174 candidate events is selected from data corresponding to an integrated\nluminosity of 5.0 inverse femtobarns. For each event the mass is reconstructed\nfrom a kinematic fit of the decay products to a t t-bar hypothesis. The\ntop-quark mass is determined simultaneously with the jet energy scale (JES),\nconstrained by the known mass of the W boson in q anti-q decays, to be 173.49\n+/- 0.43 (stat.+JES) +/- 0.98 (syst.) GeV.", "category": "hep-ex" }, { "text": "$B$ Meson Lifetimes at CDF: Measurements of the $B_u$, $B_d$, and $B_s$ meson lifetime using semileptonic\n$B_u \\rightarrow e \\nu D^0 X, B_d \\rightarrow e \\nu D^* X, B_s \\rightarrow l\n\\nu D_s X$ events and exclusive $B_u \\rightarrow \\psi^{(\\prime)} K^{(*)}, B_d\n\\rightarrow \\psi^{(\\prime)} K^{(*)}_{(s)}, B_s \\rightarrow \\psi \\phi$ events\nare presented. These results used the precise position measurements of the CDF\nSVX silicon vertex detector and were obtained from a 19.3 pb$^{-1}$ sample of\n1.8 TeV $\\overline{p}p$ collisions collected in 1992-93 at the Fermilab\nTevatron collider. Comparisons with previous measurements will be shown.", "category": "hep-ex" }, { "text": "Search for physics beyond the standard model in events with tau leptons,\n jets, and large transverse momentum imbalance in pp collisions at sqrt(s) = 7\n TeV: A search for physics beyond the standard model is performed with events\nhaving one or more hadronically decaying tau leptons, highly energetic jets,\nand large transverse momentum imbalance. The data sample corresponds to an\nintegrated luminosity of 4.98 inverse femtobarns of proton-proton collisions at\nsqrt(s) = 7 TeV collected with the CMS detector at the LHC in 2011. The number\nof observed events is consistent with predictions for standard model processes.\nLower limits on the mass of the gluino in supersymmetric models are determined.", "category": "hep-ex" }, { "text": "Jets in deep-inelastic scattering at HERA: Jet cross sections in deep-inelastic scattering over a wide region of phase\nspace have been measured at HERA. These cross section measurements provide a\nthorough test of the implementation of Quantum Chromodynamics in\nnext-to-leading order (NLO) calculations. They also provide the opportunity to\ntest the consistency of the gluon distribution in the proton as extracted from\n(mainly) inclusive DIS measurements. Comparison of the cross sections with NLO\nenables accurate extractions of the strong coupling constant, $\\alpha_s$, to be\nmade, several of which are reported here.", "category": "hep-ex" }, { "text": "Spin Physics with the PHENIX Detector System: The PHENIX experiment at RHIC has extended its scope to cover spin physics\nusing polarized proton beams. The major goals of the spin physics at RHIC are\nelucidation of the spin structure of the nucleon and precision tests of the\nsymmetries. Sensitivities of the spin physics measurements with the PHENIX\ndetector system are reviewed.", "category": "hep-ex" }, { "text": "Neutrino Physics at Muon Colliders: An overview is given of the neutrino physics potential of future muon storage\nrings that use muon collider technology to produce, accelerate and store large\ncurrents of muons.", "category": "hep-ex" }, { "text": "CP violation in the B system: The phenomenon of CP violation is crucial to understand the asymmetry between\nmatter and antimatter that exists in the Universe. Dramatic experimental\nprogress has been made, in particular in measurements of the behaviour of\nparticles containing the b quark, where CP violation effects are predicted by\nthe Kobayashi-Maskawa mechanism that is embedded in the Standard Model. The\nstatus of these measurements and future prospects for an understanding of CP\nviolation beyond the Standard Model are reviewed.", "category": "hep-ex" }, { "text": "Search for resonant t t-bar production in proton-proton collisions at\n sqrt(s) = 8 TeV: A search is performed for the production of heavy resonances decaying into\ntop-antitop quark pairs in proton-proton collisions at sqrt(s) = 8 TeV. Data\nused for the analyses were collected with the CMS detector and correspond to an\nintegrated luminosity of 19.7 inverse femtobarns. The search is performed using\nevents with three different final states, defined by the number of leptons\n(electrons and muons) from the t t-bar to W b W b decay. The analyses are\noptimized for reconstruction of top quarks with high Lorentz boosts, where jet\nsubstructure techniques are used to enhance the sensitivity. Results are\npresented for all channels and a combination is performed. No significant\nexcess of events relative to the expected yield from standard model processes\nis observed. Upper limits on the production cross section of heavy resonances\ndecaying to t t-bar are calculated. A narrow leptophobic topcolor Z' resonance\nwith a mass below 2.4 TeV is excluded at 95% confidence level. Limits are also\nderived for a broad Z' resonance with a 10% width relative to the resonance\nmass, and a Kaluza-Klein excitation of the gluon in the Randall-Sundrum model.\nThese are the most stringent limits to date on heavy resonances decaying into\ntop-antitop quark pairs.", "category": "hep-ex" }, { "text": "Exclusive Rho Rho Production in Tagged Gamma-Gamma Interactions at LEP: Exclusive rho rho production in two-photon collisions between a quasi-real,\ngamma, and a virtual, gamma*, photons is studied at LEP at centre-of-mass\nenergies 89 GeV < sqrt{s} < 209 GeV with a total integrated luminosity of 854.7\npb-1. The cross sections of the gamma gamma* -> rho rho processes are\ndetermined as a function of the photon virtuality, Q^2, and the two-photon\ncentre-of-mass energy, Wgg, in the kinematic region: 0.2 GeV^2 < Q^2 < 30 GeV^2\nand 1.1 GeV < Wgg < 3 GeV.", "category": "hep-ex" }, { "text": "Measurement of relative branching fractions of B decays to $\u03c8(2S)$\n and $J/\u03c8$ mesons: The relative rates of B-meson decays into $J/\\psi$ and $\\psi(2S)$ mesons are\nmeasured for the three decay modes in pp collisions recorded with the LHCb\ndetector. The ratios of branching fractions ($\\mathcal{B}$) are measured to be\n$\\frac{\\mathcal{B}(B^+ \\to \\psi(2S) K^+)}{\\mathcal{B}(B^+ \\to J/\\psi K^+)} =\n0.594 \\pm 0.006 (stat) \\pm 0.016 (syst) \\pm 0.015 (R_{\\psi})$,\n$\\frac{\\mathcal{B}(B^0 \\to \\psi(2S) K^{*0})}{\\mathcal{B}(B^0 \\to J/\\psi\nK^{*0})} = 0.476 \\pm 0.014 (stat) \\pm 0.010 (syst) \\pm 0.012\\,(R_{\\psi})$,\n$\\frac{\\mathcal{B}^{0}_{s}(B^0_s \\to \\psi(2S)\\phi)}{\\mathcal{B}(B^0_s \\to\nJ/\\psi\\phi)} = 0.489 \\pm 0.026 (stat) \\pm 0.021 (syst) \\pm 0.012\\,(R_{\\psi})$\nwhere the third uncertainty is from the ratio of the $\\psi(2S)$ and $J/\\psi$\nbranching fractions to $\\mu\\mu$.", "category": "hep-ex" }, { "text": "Real and virtual photon structure from dijet events: Jet production in $ep$ collisions is sensitive to the partonic structure of\nphoton. The latest measurements of dijet production from the H1 experiment\nprovide new results of the gluon density of real photons at low $x$ and, for\nthe first time, on the partonic density of virtual photons. Properties of the\nphoton remnant were measured as a function of the hard scale defined by the\n$p_T$ of the jets. The comparison of dijet cross sections with the NLO QCD\ncalculation shows the non-triviality of the concept of virtual photon\nstructure.", "category": "hep-ex" }, { "text": "Top quark mass measurements with the CMS experiment at the LHC: Measurements of the top quark mass are presented, obtained from CMS data\ncollected in proton proton collisions at the LHC at centre-of-mass energies of\n7 TeV and 8 TeV. The mass of the top quark is measured using several methods\nand channels, including the reconstructed invariant mass distribution of the\ntop quark as well as measurements based on charged particle information. The\ndependence of the mass measurement on the kinematic phase space is\ninvestigated. The results of the various channels are combined and compared to\nthe world average. The top mass is extracted from the inclusive top quark pair\nproduction cross section measured at CMS.", "category": "hep-ex" }, { "text": "Observation of $\u03c8(3686) \\to p \\bar{p} \u03b7^{\\prime}$ and improved\n measurement of $J/\u03c8\\to p \\bar{p} \u03b7^{\\prime}$: We observe the process $\\psi(3686) \\to p \\bar{p} \\eta^{\\prime}$ for the first\ntime, with a statistical significance higher than 10$\\sigma$, and measure the\nbranching fraction of $J/\\psi \\to p \\bar{p} \\eta^{\\prime}$ with an improved\naccuracy compared to earlier studies. The measurements are based on $4.48\n\\times 10^8$ $\\psi(3686)$ and $1.31 \\times 10^{9}$ $J/\\psi$ events collected by\nthe BESIII detector operating at the BEPCII. The branching fractions are\ndetermined to be $B(\\psi(3686) \\to p \\bar{p} \\eta^{\\prime}) =\n(1.10\\pm0.10\\pm0.08)\\times10^{-5}$ and $B(J/\\psi \\to p \\bar{p}\n\\eta^{\\prime})=(1.26\\pm0.02\\pm 0.07)\\times10^{-4}$, where the first\nuncertainties are statistical and the second ones systematic. Additionally, the\n$\\eta-\\eta^{\\prime}$ mixing angle is determined to be $-24^{\\circ} \\pm\n11^{\\circ}$ based on $\\psi(3686) \\to p \\bar{p} \\eta^{\\prime}$, and $-24^{\\circ}\n\\pm 9^{\\circ}$ based on $J/\\psi \\to p \\bar{p} \\eta^{\\prime}$, respectively.", "category": "hep-ex" }, { "text": "Measurements of the branching fraction, isospin asymmetry, and\n lepton-universality ratio in $B \\to J/\u03c8K$ decays at Belle II: We report a study of $B \\to J/\\psi(\\ell^{+}\\ell^{-})K$ decays, where $\\ell$\nrepresents an electron or a muon, using $e^{+}e^{-}$ collisions at the\n$\\Upsilon(4S)$ resonance. The data were collected by the Belle II experiment at\nthe SuperKEKB asymmetric-energy collider during 2019-2021, corresponding to an\nintegrated luminosity of $189$ fb$^{-1}$. The measured quantities are the\nbranching fractions (${\\mathcal B}$) of the decay channels $B^{+} \\to\nJ/\\psi(e^{+}e^{-})K^{+}$, $B^{+} \\to J/\\psi(\\mu^{+}\\mu^{-}) K^{+}$, $B^{0} \\to\nJ/\\psi(e^{+}e^{-}) K^{0}_{S}$, and $B^{0} \\to J/\\psi(\\mu^{+}\\mu^{-})K^{0}_{S}$;\nthe lepton-flavor-dependent isospin asymmetries for the electron [$A_{I}\\left(B\n\\to J/\\psi(e^{+}e^{-}) K\\right)$] and muon [$A_{I}\\left(B \\to J/\\psi(\\mu^{+}\n\\mu^{-}) K\\right)$] channels; and the ratios of branching fractions between the\nmuon and electron channels for the charged [$R_{K^{+}}\\left(J/\\psi\\right)$] and\nneutral kaon [$R_{K^{0}}\\left(J/\\psi\\right)$] case. The measurements are\nconsistent with the world-average values.", "category": "hep-ex" }, { "text": "Measurement of the W+W-gamma Cross Section and Direct Limits on\n Anomalous Quartic Gauge Boson Couplings at LEP: The process e+e- -> W+W-gamma is analysed using the data collected with the\nL3 detector at LEP at a centre-of-mass energy of 188.6GeV, corresponding to an\nintegrated luminosity of 176.8pb^-1. Based on a sample of 42 selected W+W-\ncandidates containing an isolated hard photon, the W+W-gamma cross section,\ndefined within phase-space cuts, is measured to be: sigma_WWgamma = 290 +/- 80\n+/- 16 fb, consistent with the Standard Model expectation. Including the\nprocess e+e- -> nu nu gamma gamma, limits are derived on anomalous\ncontributions to the Standard Model quartic vertices W+W- gamma gamma and W+W-Z\ngamma at 95% CL: -0.043 GeV^-2 < a_0/Lambda^2 < 0.043 GeV^-2 0.08 GeV^-2 <\na_c/Lambda^2 < 0.13 GeV^-2 0.41 GeV^-2 < a_n/Lambda^2 < 0.37 GeV^-2.", "category": "hep-ex" }, { "text": "Search for supersymmetry in multijet events with missing transverse\n momentum in proton-proton collisions at 13 TeV: A search for supersymmetry is presented based on multijet events with large\nmissing transverse momentum produced in proton-proton collisions at a\ncenter-of-mass energy of sqrt(s) = 13 TeV. The data, corresponding to an\nintegrated luminosity of 35.9 inverse femtobarns, were collected with the CMS\ndetector at the CERN LHC in 2016. The analysis utilizes four-dimensional\nexclusive search regions defined in terms of the number of jets, the number of\ntagged bottom quark jets, the scalar sum of jet transverse momenta, and the\nmagnitude of the vector sum of jet transverse momenta. No evidence for a\nsignificant excess of events is observed relative to the expectation from the\nstandard model. Limits on the cross sections for the pair production of gluinos\nand squarks are derived in the context of simplified models. Assuming the\nlightest supersymmetric particle to be a weakly interacting neutralino, 95%\nconfidence level lower limits on the gluino mass as large as 1800 to 1960 GeV\nare derived, and on the squark mass as large as 960 to 1390 GeV, depending on\nthe production and decay scenario.", "category": "hep-ex" }, { "text": "Study of the Y (4260) resonance in e+e- collisions with initial state\n radiation at Belle: We present a study of Y(4260) properties using the initial-state radiation\nprocess e^+e^- -> gamma_{ISR} Y(4260). The Y(4260) resonance is reconstructed\nin the pi^+ pi^- J/\\psi decay mode, using data collected by the Belle detector\nat the KEKB e^+e^- collider. We find a significant signal with a central mass\nvalue of (4295 +-10 +10 -3) MeV/c^2 and a width of (133 +-26 +13 -6) MeV/c^2.\nWe find Gamma_{ee}.B(Y(4260) -> pi^+ pi^- J/\\psi) = (8.7 +- 1.1 +0.3 -0.9) eV.\nThese results are preliminary.", "category": "hep-ex" }, { "text": "Search for $B^+ \\to e^+ \u03bd$ and $B^+ \\to \u03bc^+ \u03bd$ decays using\n hadronic tagging: We present a search for the rare leptonic decays $B^+ \\to e^+ \\nu_e$ and $B^+\n\\to \\mu^+ \\nu_\\mu$, using the full $\\Upsilon(4S)$ data sample of $772\\times\n10^6$ $B\\bar{B}$ pairs collected with the Belle detector at the\n$\\small\\textbf{KEKB}$ asymmetric-energy $e^+ e^-$ collider. One of the $B$\nmesons from the $\\Upsilon(4S) \\to B\\bar{B}$ decay is fully reconstructed in a\nhadronic mode, while the recoiling side is analyzed for the signal decay. We\nfind no evidence of a signal in any of the decay modes. Upper limits of the\ncorresponding branching fractions are determined as ${\\cal B}(B^+ \\to e^+\n\\nu_e)<3.5\\times 10^{-6}$ and ${\\cal B}(B^+ \\to \\mu^+ \\nu_\\mu)<2.7 \\times\n10^{-6}$ at 90$\\%$ confidence level.", "category": "hep-ex" }, { "text": "Rare decays at the LHCb experiment: Rare decays of beauty and charm hadrons offer a rich playground to make\nprecise tests of the Standard Model and look for New Physics at the level of\nquantum corrections. A review of recent LHCb results will be presented.", "category": "hep-ex" }, { "text": "Measurement of the Drell--Yan triple-differential cross section in $pp$\n collisions at $\\sqrt{s} = 8$ TeV: This paper presents a measurement of the triple-differential cross section\nfor the Drell--Yan process $Z/\\gamma^*\\rightarrow \\ell^+\\ell^-$ where $\\ell$ is\nan electron or a muon. The measurement is performed for invariant masses of the\nlepton pairs, $m_{\\ell\\ell}$, between $46$ and $200$ GeV using a sample of\n$20.2$ fb$^{-1}$ of $pp$ collisions data at a centre-of-mass energy of\n$\\sqrt{s}=8$ TeV collected by the ATLAS detector at the LHC in 2012. The data\nare presented in bins of invariant mass, absolute dilepton rapidity,\n$|y_{\\ell\\ell}|$, and the angular variable $\\cos\\theta^{*}$ between the\noutgoing lepton and the incoming quark in the Collins--Soper frame. The\nmeasurements are performed in the range $|y_{\\ell\\ell}|<2.4$ in the muon\nchannel, and extended to $|y_{\\ell\\ell}|<3.6$ in the electron channel. The\ncross sections are used to determine the $Z$ boson forward-backward asymmetry\nas a function of $|y_{\\ell\\ell}|$ and $m_{\\ell\\ell}$. The measurements achieve\nhigh-precision, below the percent level in the pole region, excluding the\nuncertainty in the integrated luminosity, and are in agreement with\npredictions. These precision data are sensitive to the parton distribution\nfunctions and the effective weak mixing angle.", "category": "hep-ex" }, { "text": "Recent charmonium results from BABAR: Recent results in the field of spectroscopy from the BABAR experiment are\nreported, with particular attention to the new states observed in ISR and\n$\\gamma \\gamma$ interactions using the full BABAR data sample. We confirm the\nstates Y(4260) and Y(4360) with higher precision and for the first time the\nstate Y(4660) is observed. We do not confirm the Y(4008) state reported by\nBelle. In addition, the analysis of the invariant mass of the $J/\\psi \\omega$\nsystem produced in $\\gamma \\gamma$ interactions is presented in confirmation of\nthe Belle observation of the X(3915) in this process.", "category": "hep-ex" }, { "text": "New H1 results on isolated leptons and missing pt at HERA: The search for events containing isolated leptons (electrons or muons) and\nmissing transverse momentum produced in $e^{\\pm}p$ collisions is performed with\nthe H1 detector at HERA in the period 1994--2005. The analysed data sample\ncorresponds to an integrated luminosity of 279 pb$^{-1}$, which includes 53\npb$^{-1}$ of $e^{+}p$ data and 107 pb$^{-1}$ of $e^{-}p$ data from the new\nHERA~II phase. A total of 40 events are observed in the data, compared to a\nStandard Model (SM) prediction of 34.3 $\\pm$ 4.8. At large hadronic transverse\nmomentum $P_{T}^{X} >$ 25 GeV, a total of 17 events are observed compared to\n9.0 $\\pm$ 1.5 predicted by the SM. In this region, 15 events are observed in\nthe $e^{+}p$ data compared to a SM prediction of 4.6 $\\pm$ 0.8, whereas in the\n$e^{-}p$ data 2 events are observed compared to a SM prediction of 4.4 $\\pm$\n0.7.", "category": "hep-ex" }, { "text": "Measurement of the absolute branching ratios for semileptonic K+/-\n decays with the KLOE detector: Using a sample of over 600 million phi->K+K- decays collected at the Dafne\ne+e- collider, we have measured with the KLOE detector the absolute branching\nratios for the charged kaon semileptonic decays, K+/- -> p0 e nu (gamma) (Ke3)\nand K+/- -> p0 mu nu (gamma) (Kmu3). The results, BR(Ke3) = 0.04965 +/-\n0.00038_{stat} +/- 0.00037_{syst} and BR(Kmu3) = 0.03233 +/- 0.00029_{stat} +/-\n0.00026_{syst}, are inclusive of radiation. Accounting for correlations, we\nderive the ratio Kmu3/Ke3 = 0.6511+/-0.0064. Using the semileptonic form\nfactors measured in the same experiment, we obtain V_{us}f_{+}(0) = 0.2141 +/-\n0.0013.", "category": "hep-ex" }, { "text": "Hadronization in Nuclei - Multidimensional Study: Hadron multiplicities in semi-inclusive deep-inelastic scattering were\nmeasured on neon, krypton and xenon targets relative to deuterium at an\nelectron-beam energy of 27.6 GeV at HERMES. These ratios were determined as a\nfunction of the virtual-photon energy nu, its virtuality Q2, the fractional\nhadron energy z and the transverse hadron momentum with respect to the\nvirtual-photon direction p_t . Dependences were analysed separately for\npositively and negatively charged pions and kaons as well as protons and\nantiprotons in a two-dimensional representation. These results will help to\nconstrain mechanisms and models of hadronization much more decisively than by\nthe use of integrated results as traditionally done. A few features particular\nto the two-dimensional representation are highlighted in this contribution.", "category": "hep-ex" }, { "text": "Super-ORCA: Measuring the leptonic CP-phase with Atmospheric Neutrinos\n and Beam Neutrinos: Studying the atmospheric neutrino oscillation probabilities below 2 GeV with\na multi-megaton Cherenkov detector allows for a measurement of the leptonic\nCP-phase $\\delta_{CP}$. The most relevant CP-sensitive energy range is below\nthe neutrino detection threshold of KM3NeT/ORCA, which is an underwater\nCherenkov detector optimised to determine the neutrino mass ordering by\nmeasuring the oscillation pattern of 3-30 GeV atmospheric neutrinos. With\nSuper-ORCA, a $\\sim 10$ times more-densely instrumented version of ORCA, the\ndetection threshold can be lowered and the event reconstruction capabilities\nimproved.\n In this paper, the key detector performance indicators for a possible\nSuper-ORCA detector and the sensitivity to $\\delta_{CP}$ with atmospheric\nneutrinos are presented. Including systematics, a 1$\\sigma$-resolution on\n$\\delta_{CP}$ of about $38^\\circ$ ($23^\\circ$) is achieved for $\\delta_{CP}=0$\n($\\delta_{CP}=\\pi/2$) after 10 years. In addition, the potential of using a\nneutrino beam from the Protvino accelerator facility to the Super-ORCA detector\nis discussed. With this, a 1$\\sigma$-resolution on $\\delta_{CP}$ of about\n$10^\\circ$ ($16^\\circ$) is achieved for $\\delta_{CP}=0$ ($\\delta_{CP}=\\pi/2$)\nafter 10 years.", "category": "hep-ex" }, { "text": "Observation of narrow baryon resonance in $pK^0_s$ mode in\n $pA$-interactions at $70 GeV/c$ with SVD-2 setup: We report on the SVD-2 experiment data analysis aimed to search for an exotic\nbaryon state, the $\\Theta^+$-baryon, in a $pK^0_s$ decay mode with IHEP U-70\naccelerator proton beam at $70 GeV/c$. A resonant structure with\n$M=1526\\pm3(stat.)\\pm 3(syst.)~MeV/c^2$ and $\\Gamma < 24 MeV/c^2$ was found in\nthe $pK^0_s$ invariant mass spectrum, with the statistical significance of this\npeak estimated as $5.6~\\sigma$.", "category": "hep-ex" }, { "text": "W and Z production in the forward region at LHCb: Measurements of electroweak boson production in pp collisions at $\\sqrt{s} =\n7$ TeV are presented using the decays $W \\rightarrow \\mu\\nu$, $Z \\rightarrow\n\\mu\\mu$ and $Z \\rightarrow \\tau\\tau$ recorded using the LHCb detector at the\nLHC. For muonic $W$ and $Z$ decays, the data sample corresponds to an\nintegrated luminosity of 37.1 $\\pm$ 1.3 pb$^{-1}$. Here the $W$ and $Z$ bosons\nare reconstructed from muons with transverse momenta, $p_{T}$, above 20 GeV and\npseudorapidity, $\\eta$, between 2 and 4.5, and, in the case of the $Z$, a\ndimuon invariant mass $M_{Z}$ between 60 GeV and 120 GeV. For $Z$ decays to tau\nlepton final states, 247 pb$^{-1}$ of data has been used. Here one tau is\nidentified through its decay to a muon and neutrinos; the other through its\ndecay to an electron or muon and neutrinos. The cross-sections are measured to\nbe: $\\sigma(W^{+}\\rightarrow\\mu^{+}\\nu) = $ 808 $\\pm$ 7 $\\pm$ 28 $\\pm$ 28 pb;\n$\\sigma(W^{+}\\rightarrow\\mu^{+}\\nu) = $ 634 $\\pm$ 7 $\\pm$ 21 $\\pm$ 22 pb;\n$\\sigma(Z\\rightarrow\\mu\\mu) = $ 74.9 $\\pm$ 1.6 $\\pm$ 3.8 $\\pm$ 2.6 pb;\n$\\sigma(Z\\rightarrow\\tau\\tau) = $ 82 $\\pm$ 8 $\\pm$ 7 $\\pm$ 4 pb. Here the first\nerror is statistical, the second is systematic and the third is due to the\nluminosity determination. For muonic final states, differential measurements,\ncross-section ratios and the $W$ charge asymmetry are also measured in the same\nkinematic region. The ratio of the $Z\\rightarrow\\tau\\tau$ and\n$Z\\rightarrow\\mu\\mu$ cross-sections has been measured to be 1.09 $\\pm$ 0.17,\nconsistent with lepton universality. Theoretical predictions, calculated at\nnext-to-next-to-leading order (NNLO) in QCD using recent parton distribution\nfunctions, are found to be in agreement with the measurements.", "category": "hep-ex" }, { "text": "Diffractive Deep-Inelastic Scattering: New results on diffractive deep-inelastic $e p$ scattering at HERA are\npresented using data taken in 1994 with the H1 detector. The cross section for\ndiffractive deep-inelastic scattering is measured in terms of a diffractive\nstructure function $F_2^{D(3)}(\\beta,Q^2,\\xpom)$ over an extended kinematic\nrange. The dependence of $F_2^{D(3)}$ on $\\xpom$ is found not to depend on\n$Q^2$, but to depend on $\\beta$. Therefore the $\\xpom$ dependence no longer\nfactorizes. The $Q^2$ and $\\beta$ dependence of $F_2^{D(3)}$ is analyzed after\nan integration over the dependence on $\\xpom$. For fixed $\\beta$ a clear rise\nwith $\\log Q^2$ is observed, persisting up to high values of $\\beta$. In terms\nof the Altarelli-Parisi (DGLAP) QCD evolution equations, these scaling\nviolations give clear indications for a gluon dominated process. Subsequently\nan attempt is made to quantify the parton content of the diffractive exchange\nusing the DGLAP evolution. At the starting scale a ``leading'' gluon\ndistribution is found which contributes about $80 \\%$ of the momentum in the\ndiffractive exchange. Measurements of the hadronic final state (energy flow and\nproduction of $D^{*}$ mesons) are found to be consistent with the predictions\nof a model of deep-inelastic electron pomeron scattering using the information\non the parton content obtained.", "category": "hep-ex" }, { "text": "Observation of excited $\u03a9_c^0$ baryons in $\u03a9_b^- \\to \u039e_c^+\n K^-\u03c0^-$ decays: The first observation of the $\\Omega_b^- \\to \\Xi_c^+ K^- \\pi^-$ decay is\nreported using $pp$ collision data at centre-of-mass energies of 7, 8 and\n13\\,$\\mathrm{TeV}$ collected by the LHCb experiment, corresponding to an\nintegrated luminosity of 9\\,$\\mathrm{fb}^{-1}$. Four excited $\\Omega_c^0$\nbaryons are observed in the $\\Xi_c^+ K^-$ mass projection of the $\\Omega_b^-\n\\to \\Xi_c^+ K^- \\pi^-$ decays with the significance of each exceeding five\nstandard deviations. They coincide with the states previously observed in\nprompt \\proton\\proton and $e^+e^-$ production. Relative production rates,\nmasses and natural widths of the states are measured, and a test of spin\nhypotheses is performed. Moreover, the branching ratio of $\\Omega_b^- \\to\n\\Xi_c^+ K^- \\pi^-$ is measured relative to the $\\Omega_b^- \\to \\Omega_c^0\n\\pi^-$ decay mode and a precise measurement of the $\\Omega_b^-$ mass of\n\\mbox{$6044.3 \\pm 1.2 \\pm 1.1^{\\,+0.19}_{\\,-0.22}\\,\\mathrm{MeV}$} is obtained.", "category": "hep-ex" }, { "text": "Observation of new resonances decaying to $D\u03c0$ and $D^*\u03c0$ in\n inclusive $e^+e^-$ collisions near $\\sqrt{s}=$10.58 GeV: We present a study of the $D^+\\pi^-$, $D^0\\pi^+$, and $D^{*+}\\pi^-$ systems\nin inclusive $e^+e^- \\rightarrow c\\bar{c}$ interactions in a search for new\nexcited $D$ meson states. We use a dataset, consisting of $\\sim$454 fb$^{-1}$,\ncollected at center-of-mass energies near 10.58 GeV by the BABAR detector at\nthe SLAC PEP-II asymmetric-energy collider. We observe, for the first time,\ncandidates for the radial excitations of the $D^0$, $D^{*0}$, and $D^{*+}$, as\nwell as the L=2 excited states of the $D^0$ and $D^+$, where $L$ is the orbital\nangular momentum of the quarks.", "category": "hep-ex" }, { "text": "New Tagging Method of B Flavor of Neutral B Meson in CP Violation\n Measurement in Asymmetric B-Factory Experiment: In CP violation measurements in asymmetric B-factory experiments, a\ndetermination of the B flavor of the neutral B mesons is necessary. A new\nmethod to this purpose using only three vectors of charged particles has been\ndeveloped. This method (weighted charge method) does not require either lepton\nidentification or charged-kaon identification. The tagging efficiency,\nprobability for incorrect tagging, and effective tagging efficiency of this\nmethod are 43.1, 18.3, and 17.3\\%, respectively.", "category": "hep-ex" }, { "text": "MACRO and the atmospheric neutrino problem: After a brief presentation of the MACRO detector we discuss the updated data\non atmospheric muon neutrinos, and the interpretation in terms of neutrino\noscillations.", "category": "hep-ex" }, { "text": "Search for resonances decaying to a pair of Higgs bosons in the\n $\\mathrm{b\\overline{b}q\\overline{q}'}\\ell\u03bd$ final state in proton-proton\n collisions at $\\sqrt{s} =$ 13 TeV: A search for new massive particles decaying into a pair of Higgs bosons in\nproton-proton collisions at a center-of-mass energy of 13 TeV is presented.\nData were collected with the CMS detector at the LHC, corresponding to an\nintegrated luminosity of 35.9 fb$^{-1}$. The search is performed for resonances\nwith a mass between 0.8 and 3.5 TeV using events in which one Higgs boson\ndecays into a bottom quark pair and the other decays into two W bosons that\nsubsequently decay into a lepton, a neutrino, and a quark pair. The Higgs boson\ndecays are reconstructed with techniques that identify final state quarks as\nsubstructure within boosted jets. The data are consistent with standard model\nexpectations. Exclusion limits are placed on the product of the cross section\nand branching fraction for generic spin-0 and spin-2 massive resonances. The\nresults are interpreted in the context of radion and bulk graviton production\nin models with a warped extra spatial dimension. These are the best results to\ndate from searches for an HH resonance decaying to this final state, and they\nare comparable to the results from searches in other channels for resonances\nwith masses below 1.5 TeV.", "category": "hep-ex" }, { "text": "A conceptual design of TOF based on MRPC technology for the future\n electron-positron Higgs factory: Future electron-positron Higgs factories could provide excellent\nopportunities to examine the Standard Model and search for new physics with\nmuch higher precision than the LHC. A precise particle identification is\ncrucial for the physics program at these future colliders and can be achieved\nvia precise time-of-flight (TOF) measurements of the final state particles. In\nthis paper, we propose a conceptual design of TOF system based on the multigap\nresistive plate chamber (MRPC) technology for future electron-positron Higgs\nfactories. This TOF system has a time resolution of < 35 ps, a total active\narea of 77m2, and a construction budget of the order of 5 million USD.\nKeywords: MRPC, TOF, PID, CEPC", "category": "hep-ex" }, { "text": "Search for new phenomena with large jet multiplicities and missing\n transverse momentum using large-radius jets and flavour-tagging at ATLAS in\n 13 TeV $pp$ collisions: A search is presented for particles that decay producing a large jet\nmultiplicity and invisible particles. The event selection applies a veto on the\npresence of isolated electrons or muons and additional requirements on the\nnumber of b-tagged jets and the scalar sum of masses of large-radius jets.\nHaving explored the full ATLAS 2015-2016 dataset of LHC proton-proton\ncollisions at $\\sqrt{s}=13~\\mathrm{TeV}$, which corresponds to 36.1 fb$^{-1}$\nof integrated luminosity, no evidence is found for physics beyond the Standard\nModel. The results are interpreted in the context of simplified models inspired\nby R-parity-conserving and R-parity-violating supersymmetry, where gluinos are\npair-produced. More generic models within the phenomenological minimal\nsupersymmetric Standard Model are also considered.", "category": "hep-ex" }, { "text": "New Phenomena II: Recent Results from the Fermilab Tevatron: The CDF and D\\O collaborations continue to search for new physics using more\nthan 100~pb$^{-1}$ of \\xxbar{p} collisions at $\\sqrt{s}=1.8$ TeV collected at\nthe Fermilab Tevatron. We present recent results from both experiments on\nR-parity violating Supersymmetry and $Z'$/Technicolor production with $ee$ and\n\\xxbar{t} final states. In addition we introduce Sherlock, a new\nquasi-model-independent search strategy.", "category": "hep-ex" }, { "text": "Search for the Decay J/psi -> gamma + invisible: A search for J/psi radiative decay to weakly interacting neutral final states\nwas performed using the CLEO-c detector at CESR. A total of 3.7 x 10^{6} tagged\nJ/psi events was collected at the psi(2S) resonance and used to study the decay\nJ/psi -> gamma+X, where X is a narrow state that is invisible to the detector.\nNo significant signal was observed and upper limits on the branching fraction\nwere set for masses m_X up to 960 MeV/c^2. The upper limit corresponding to\nm_X=0 is 4.3x 10^{-6} at the 90% confidence level.", "category": "hep-ex" }, { "text": "Observation of the rare decay B+->K+pi0pi0 and measurement of the\n quasi-two body contributions B+->K*(892)+pi0, B+->f0(980)K+ and B+->chic0K+: We report an analysis of the charmless hadronic decays of charged B meson to\nthe final state K+pi0pi0, using a data sample of 470+/-2.8 million BBbar events\ncollected at the Y(4S) resonance. We observe an excess of signal events, with a\nsignificance above 10 standard deviations including systematic uncertainties,\nand measure the branching fraction and CP asymmetry to be\nB(B+->K+pi0pi0)=(16.2+/-1.2+/-1.5)x10^-6 and\nA_CP(B+->K+pi0pi0)=-0.06+/-0.06+/-0.04, where the uncertainties are statistical\nand systematic respectively. Additionally we study the contributions of the\nB+->K*(892)+pi0, B+->f0(980)K+ and B+->chic0K+ quasi-two body decays. We report\nthe world's best measurements of the branching fractions and CP asymmetry of\nthe B+->K+pi0pi0 and B+->K*(892)+pi0 channels.", "category": "hep-ex" }, { "text": "Spin Structure Functions g_1 and g_2 for the Proton and Deuteron: The experiment E155 at SLAC measured the spin structure functions g_1 and g_2\nof the proton and deuteron. The experiment used deep inelastic scattering of\n48.3 GeV longitudinally polarized electrons incident on polarized solid\n^{15}NH_3 and ^{6}LiD targets. The data taken by three independent\nspectrometers covered a kinematic range of 0.014 < x < 0.9 and 1 (GeV/c)^2 <\nQ^2 < 40 (GeV/c)^2. Due to the high luminosity and polarization available at\nSLAC the data on g_1 are to date the most precise in this kinematic range. The\nx and Q^2 dependence of g_1 has been studied using NLO PQCD fits, allowing\nextraction of values for the Bjorken sum rule and quark and gluon spin\ncontributions to the nucleon. Results are presented for g_1 and g_2 for the\nproton and deuteron.", "category": "hep-ex" }, { "text": "Search for dark matter in events with a leptoquark and missing\n transverse momentum in proton-proton collisions at 13 TeV: A search is presented for dark matter in proton-proton collisions at a\ncenter-of-mass energy of $\\sqrt{s} =$ 13 TeV using events with at least one\nhigh transverse momentum ($p_\\mathrm{T}$) muon, at least one\nhigh-$p_\\mathrm{T}$ jet, and large missing transverse momentum. The data were\ncollected with the CMS detector at the CERN LHC in 2016 and 2017, and\ncorrespond to an integrated luminosity of 77.4 fb$^{-1}$. In the examined\nscenario, a pair of scalar leptoquarks is assumed to be produced. One\nleptoquark decays to a muon and a jet while the other decays to dark matter and\nlow-$p_\\mathrm{T}$ standard model particles. The signature for signal events\nwould be significant missing transverse momentum from the dark matter in\nconjunction with a peak at the leptoquark mass in the invariant mass\ndistribution of the highest $p_\\mathrm{T}$ muon and jet. The data are observed\nto be consistent with the background predicted by the standard model. For the\nfirst benchmark scenario considered, dark matter masses up to 500 GeV are\nexcluded for leptoquark masses $M_\\mathrm{LQ}$ $\\approx$ 1400 GeV, and up to\n300 GeV for $M_\\mathrm{LQ}$ $\\approx$ 1500 GeV. For the second benchmark\nscenario, dark matter masses up to 600 GeV are excluded for $M_\\mathrm{LQ}$\n$\\approx$ 1400 GeV.", "category": "hep-ex" }, { "text": "Measurement of Branching Fractions for $B\\to \u03c7_{c1(2)} K (K^*)$ at\n Belle: We have measured the branching fractions for the exclusive decay modes $B\\to\n{\\chi}_{c1(2)} K(K^*)$ using a $140~{\\rm fb}^{-1}$ data sample collected by the\nBelle detector at the KEKB asymmetric-energy $e^+e^-$ collider. The measured\nbranching fractions for $B^+\\to {\\chi}_{c1}K^+$, $B^0\\to {\\chi}_{c1}K^0$,\n$B^0\\to {\\chi}_{c1}K^{*0}$ and $B^+\\to {\\chi}_{c1}K^{*+}$ decay modes are\n$(4.5\\pm 0.2\\pm0.5)\\times 10^{-4}$, $(3.5\\pm 0.3\\pm0.5)\\times 10^{-4}$,\n$(3.1\\pm 0.3\\pm0.7)\\times 10^{-4}$ and $(4.1\\pm 0.6\\pm0.9)\\times 10^{-4}$,\nrespectively, where the first error is statistical and the second error is\nsystematic. We do not observe statistically significant signals for the $B\\to\n{\\chi}_{c2}K(K^*)$ decay modes and set upper limits at the 90% confidence\nlevel. We also study the helicity distribution for $B\\to {\\chi}_{c1} K^*$ decay\nmode and show that the longitudinal polarization component is dominant. {{\\it\nKeywords:} {$B$-meson, Charmonium, Branching Fractions, Polarization}} {{\\it\nPACS:} 13.25.Hw, 11.30.Er}", "category": "hep-ex" }, { "text": "Search for weakly interacting sub-eV particles with the OSQAR\n laser-based experiment: results and perspectives: Recent theoretical and experimental studies highlight the possibility of new\nfundamental particle physics beyond the Standard Model that can be probed by\nsub-eV energy experiments. The OSQAR photon regeneration experiment looks for\n\"Light Shining through a Wall\" (LSW) from the quantum oscillation of optical\nphotons into \"Weakly Interacting Sub-eV Particles\" (WISPs), like axion or\naxion-like particles (ALPs), in a 9 T transverse magnetic field over the\nunprecedented length of $2 \\times 14.3$ m. No excess of events has been\ndetected over the background. The di-photon couplings of possible new light\nscalar and pseudo-scalar particles can be constrained in the massless limit to\nbe less than $8.0\\times10^{-8}$ GeV$^{-1}$. These results are very close to the\nmost stringent laboratory constraints obtained for the coupling of ALPs to two\nphotons. Plans for further improving the sensitivity of the OSQAR experiment\nare presented.", "category": "hep-ex" }, { "text": "Results from the first heavy ion run at the LHC: Early November 2010, the LHC collided for the first time heavy ions, Pb on\nPb, at a centre-of-mass energy of 2.76 TeV/nucleon. This date marked both the\nend of almost 20 years of preparing for nuclear collisions at the LHC, as well\nas the start of a new era in ultra-relativistic heavy ion physics at energies\nexceeding previous machines by more than an order of magnitude. This\ncontribution summarizes some of the early results from all three experiments\nparticipating in the LHC heavy ion program (ALICE, ATLAS, and CMS), which show\nthat the high density matter created at the LHC, while much hotter and larger,\nstill behaves like the very strongly interacting, almost perfect liquid\ndiscovered at RHIC. Some surprising and even puzzling results are seen in\nparticle ratios, jet-quenching, and Quarkonia suppression observables. The\noverall experimental conditions at the LHC, together with its set of powerful\nand state-of-the-art detectors, should allow for precision measurements of\nquark-gluon-plasma parameters like viscosity and opacity.", "category": "hep-ex" }, { "text": "Measurement of the Branching Fractions for Inclusive $B^-$ and $\\bar\n B^0$ Decays to Flavor-tagged $D$, $D_s$ and $\u039b_c$: We report on the inclusive branching fractions of $B^-$ and of ${\\bar B}^0$\nmesons decaying to ${D^0 X}$, ${{\\bar D}^0 X}$, ${D^+ X}$, ${D^- X}$, ${D_s^+\nX}$, ${D_s^- X}$, ${\\Lambda_c^+ X}$, ${{\\bar \\Lambda}_c^- X}$, based on a\nsample of 88.9 million $B \\bar B$ events recorded with the $BABAR$ detector at\nthe $\\Upsilon(4S)$ resonance. Events are selected by completely reconstructing\none $B$ and searching for a reconstructed charmed particle in the rest of the\nevent. We measure the number of charmed and of anti-charmed particles per $B$\ndecay and derive the total charm yield per $B^-$ decay, $n_c^- = 1.313 \\pm\n0.037 \\pm 0.062 ^{+0.063}_{-0.042} $, and per ${\\bar B}^0$ decay, $n_c^0 =\n1.276 \\pm 0.062 \\pm 0.058 ^{+0.066}_{-0.046}$ where the first uncertainty is\nstatistical, the second is systematic, and the third reflects the charm\nbranching-fraction uncertainties.", "category": "hep-ex" }, { "text": "Analysis of Neutral Current Interactions in MINOS: A Search for Sterile\n Neutrinos: A search for disappearance of active neutrinos over a baseline of 735 km was\nconducted using the NuMI neutrino beam and the MINOS detectors. The data\nanalyzed correspond to an exposure of 3.18x10^{20} protons on target. The data\nare fitted to neutrino oscillation models in which mixing with one sterile\nneutrino is assumed. A comparison of the neutral-current-like spectrum at the\nFD with the expectation derived from the near detector measurement shows that\nthe fraction of disappearing muon neutrinos converting to a sterile state is\nless than 52% at the 90% confidence level. In addition, the possibility of\ndecay of active neutrinos into sterile species occurring concurrently with\nneutrino oscillations was analyzed. Pure neutrino decay is disfavored at 5.4\nsigma as an alternate explanation to oscillations for the depletion of muon\nneutrinos at 735 km. The methodology employed in the analysis of neutral\ncurrent neutrino events observed in MINOS is described and newly obtained\nresults are presented.", "category": "hep-ex" }, { "text": "Search for Dimuon Decays of a Light Scalar Boson in Radiative\n Transitions Upsilon -> gamma A0: We search for evidence of a light scalar boson in the radiative decays of the\nUpsilon(2S) and Upsilon(3S) resonances: Upsilon(2S,3S)-> gamma A0, A0 -> mu^+\nmu^-. Such a particle appears in extensions of the Standard Model, where a\nlight CP-odd Higgs boson naturally couples strongly to b-quarks. We find no\nevidence for such processes in the mass range 0.212<= m(A0)<= 9.3 GeV in the\nsamples of 99*10^6 Upsilon(2S) and 122*10^6 Upsilon(3S) decays collected by the\nBABAR detector at the PEP-II B-factory and set stringent upper limits on the\neffective coupling of the b quark to the A0. We also limit the dimuon branching\nfraction of the eta_b meson: BR(eta_b->mu^+mu^-)<0.9% at 90% confidence level.", "category": "hep-ex" }, { "text": "Status and Perspectives of Neutrino Physics: I will first give a brief but comprehensive review of the status of our\nknowledge in neutrino physics. With reference to a not too far future I will\nthen discuss the perspectives that appear to me to be most important and\npromising.", "category": "hep-ex" }, { "text": "Models of the hadron structure and Data of the TOTEM Collaboration: The region of the small and large momentum transfer is examined from a view\npoint of the contribution of the different parts of the scattering amplitude,\nsoft and hard pomeron, and odderon contribution. The new model taking into\naccount the different moments of the General Parton Distribution of the hadron\nis presented. The comparison with the preliminary data of the TOTEM\nCollaboration at an energy of 7 TeV is made.", "category": "hep-ex" }, { "text": "Transverse Spin Physics at HERMES: HERMES has measured azimuthal single-spin asymmetries of charged pions\nproduced in deep-inelastic scattering of positrons on a transversely polarised\nhydrogen target. The presented azimuthal moments provide access to two yet\nunknown quark distribution functions, the transversity distribution function\n\\delta q and the Sivers function f_{1T}^{perp}.", "category": "hep-ex" }, { "text": "Theta 13 Determination with Nuclear Reactors: Recently there has been a lot of interest around the world in the use of\nnuclear reactors to measure theta 13, the last undetermined angle in the\n3-neutrino mixing scenario. In this paper the motivations for theta 13\nmeasurement using short baseline nuclear reactor experiments are discussed. The\nfeatures of such an experiment are described in the context of Double Chooz,\nwhich is a new project planned to start data-taking in 2008, and to reach a\nsensitivity of sinsq(2 theta 13) < 0.03.", "category": "hep-ex" }, { "text": "Measurement of the electroweak production of a Z boson and two jets in\n proton-proton collisions at 7 and 8 TeV: A measurement of the electroweak production cross section of a Z boson and\ntwo jets is performed using proton-proton collision data at centre-of-mass\nenergies of 7 and 8 TeV. The data is collected by the CMS experiment at the LHC\nwith an integrated luminosity of 5 and 19 fb$^{-1}$, respectively. A study on\nthe hadronic activity between the two tagging jets is also presented.", "category": "hep-ex" }, { "text": "Exclusive $\u03c1^0$ Meson Photoproduction with a Leading Neutron at HERA: A first measurement is presented of exclusive photoproduction of $\\rho^0$\nmesons associated with leading neutrons at HERA. The data were taken with the\nH1 detector in the years $2006$ and $2007$ at a centre-of-mass energy of\n$\\sqrt{s}=319$ GeV and correspond to an integrated luminosity of $1.16$\npb$^{-1}$. The $\\rho^0$ mesons with transverse momenta $p_T<1$ GeV are\nreconstructed from their decays to charged pions, while leading neutrons\ncarrying a large fraction of the incoming proton momentum, $x_L>0.35$, are\ndetected in the Forward Neutron Calorimeter. The phase space of the measurement\nis defined by the photon virtuality $Q^2 < 2$ GeV$^2$, the total energy of the\nphoton-proton system $20 < W_{\\gamma p} < 100$ GeV and the polar angle of the\nleading neutron $\\theta_n < 0.75$ mrad. The cross section of the reaction\n$\\gamma p \\to \\rho^0 n \\pi^+$ is measured as a function of several variables.\nThe data are interpreted in terms of a double peripheral process, involving\npion exchange at the proton vertex followed by elastic photoproduction of a\n$\\rho^0$ meson on the virtual pion. In the framework of one-pion-exchange\ndominance the elastic cross section of photon-pion scattering, $\\sigma^{\\rm\nel}(\\gamma\\pi^+ \\to \\rho^0\\pi^+)$, is extracted. The value of this cross\nsection indicates significant absorptive corrections for the exclusive reaction\n$\\gamma p \\to \\rho^0n\\pi^+$.", "category": "hep-ex" }, { "text": "Measurement of inclusive $\u03c0^0$ production in the Charged-Current\n Interactions of Neutrinos in a 1.3-GeV wide band beam: In this paper we report on the measurement of the rate of inclusive $\\pi^0$\nproduction induced by charged-current neutrino interactions in a C$_8$H$_8$\ntarget at a mean energy of 1.3 GeV in the K2K near detector. Out of a sample of\n11,606 charged current neutrino interactions, we select 479 $\\pi^0$ events with\ntwo reconstructed photons. We find that the cross section for the inclusive\n$\\pi^0$ production relative to the charged-current quasi-elastic cross section\nis\n$$\\frac{\\sigma_{CC\\pi^0}}{\\sigma_{CCQE}}=0.426\\pm0.032(stat.)\\pm0.035(syst.)$$\nThe energy dependent cross section ratio is also measured. The results are\nconsistent with previous experiments for exclusive channels on different\ntargets.", "category": "hep-ex" }, { "text": "Search for dark photons using a multilayer dielectric haloscope equipped\n with a single-photon avalanche diode: We report on the results of the search for dark photons with mass around\n1.5$\\,\\rm eV/c^2$ using a multilayer dielectric haloscope equipped with an\naffordable and commercially available photosensor. The multilayer stack, which\nenables the conversion of dark photons (DP) to Standard Model photons, is made\nof 23 bilayers of alternating SiO$_2$ and Si$_3$N$_4$ thin films with linearly\nincreasing thicknesses through the stack (a configuration known as a \"chirped\nstack\"). The thicknesses have been chosen according to an optimisation\nalgorithm in order to maximise the DP-photon conversion in the energy region\nwhere the photosensor sensitivity peaks. This prototype experiment, baptised\nMuDHI (Multilayer Dielectric Haloscope Investigation) by the authors of this\npaper, has been designed, developed and run at the Astroparticle Laboratory of\nNew York University Abu Dhabi, which marks the first time a dark matter\nexperiment has been operated in the Middle East. No significant signal excess\nis observed, and the method of maximum log-likelihood is used to set exclusion\nlimits at $90\\%$ confidence level on the kinetic mixing coupling constant\nbetween dark photons and ordinary photons.", "category": "hep-ex" }, { "text": "Double parton interactions in photon + 3 jet and photon + b/c jet + 2\n jet events in ppbar collisions at sqrt{s}=1.96 TeV: We determine the fraction of events with double parton (DP) scattering in a\nsingle ppbar collision at sqrt{s}=1.96 TeV in samples of photon + 3 jet and\nphoton + b/c jet + 2 jet events collected with the D0 detector and\ncorresponding to an integrated luminosity of about 8.7 fb^{-1}. The DP\nfractions and effective cross sections (sigma_eff) are measured for both event\nsamples using the same kinematic selections. The measured DP fractions range\nfrom 0.21 to 0.17, with effective cross sections in the photon + 3 jet and\nphoton + b/c jet + 2 jet samples of sigma_eff^incl = 12.7 +- 0.2 (stat) +- 1.3\n(syst) mb and sigma_eff^HF = 14.6 +- 0.6 (stat) +- 3.2 (syst) mb, respectively.", "category": "hep-ex" }, { "text": "Constraints on Neutrino Lifetime from the Sudbury Neutrino Observatory: The long baseline between the Earth and the Sun makes solar neutrinos an\nexcellent test beam for exploring possible neutrino decay. The signature of\nsuch decay would be an energy-dependent distortion of the traditional survival\nprobability which can be fit for using well-developed and high precision\nanalysis methods. Here a model including neutrino decay is fit to all three\nphases of $^8$B solar neutrino data taken by the Sudbury Neutrino Observatory.\nThis fit constrains the lifetime of neutrino mass state $\\nu_2$ to be\n${>8.08\\times10^{-5}}$ s/eV at $90\\%$ confidence. An analysis combining this\nSNO result with those from other solar neutrino experiments results in a\ncombined limit for the lifetime of mass state $\\nu_2$ of ${>1.04\\times10^{-3}}$\ns/eV at $99\\%$ confidence.", "category": "hep-ex" }, { "text": "Time synchronization system of Baikal-GVD: The Baikal-GVD neutrino telescope currently consists of 8 clusters of 288\noptical modules (photodetectors). One cluster comprises 8 strings, each of\nwhich is subdivided into 3 sections of 12 optical modules. This paper presents\nthe methods of time synchronization between the different GVD components\n(optical modules, sections, clusters) and estimations of time synchronization\naccuracy.", "category": "hep-ex" }, { "text": "Search for Narrow Diphoton Resonances and for gamma-gamma+W/Z Signatures\n in p\\bar p Collisions at sqrt(s)=1.8 TeV: We present results of searches for diphoton resonances produced both\ninclusively and also in association with a vector boson (W or Z) using 100\npb^{-1} of p\\bar p collisions using the CDF detector. We set upper limits on\nthe product of cross section times branching ratio for both p\\bar\np\\to\\gamma\\gamma + X and p\\bar p\\to\\gamma\\gamma + W/Z. Comparing the inclusive\nproduction to the expectations from heavy sgoldstinos we derive limits on the\nsupersymmetry-breaking scale sqrt{F} in the TeV range, depending on the\nsgoldstino mass and the choice of other parameters. Also, using a NLO\nprediction for the associated production of a Higgs boson with a W or Z boson,\nwe set an upper limit on the branching ratio for H\\to\\gamma\\gamma. Finally, we\nset a lower limit on the mass of a `bosophilic' Higgs boson (e.g. one which\ncouples only to \\gamma, W, and Z$ bosons with standard model couplings) of 82\nGeV/c^2 at 95% confidence level.", "category": "hep-ex" }, { "text": "Study of CP asymmetry in B0-B0bar mixing with inclusive dilepton events: We present a measurement of the asymmetry $A_{CP}$ between same-sign\ninclusive dilepton samples $\\ell^+ \\ell^+$ and $\\ell^- \\ell^-$ ($\\ell= e, \\mu$)\nfrom semileptonic B decays in Y(4S) --> BBbar events, using the complete data\nset recorded by the BABAR experiment near the Y(4S) resonance, corresponding to\n471 million BBbar pairs. The asymmetry A_{CP} allows comparison between the\nmixing probabilities P(B0bar --> B0) and P(B0 --> B0bar), and therefore probes\nCP and T violation. The result, $A_{CP} = (-3.9 \\pm 3.5 (stat) \\pm 1.9 (syst))\n\\times 10^{-3}$, is consistent with the Standard Model expectation.", "category": "hep-ex" }, { "text": "The CLEO-III RICH Detector and Beam Test Results: We are constructing a Ring Imaging Cherenkov detector (RICH) for the CLEO III\nupgrade for precision charged hadron identification. The RICH uses plane and\nsawtooth LiF crystals as radiators, MWPCs as photon detectors with TEA as the\nphoto-sensitive material, and low-noise Viking readout electronics. Results of\na beam test of the first two out of total 30 sectors are presented.", "category": "hep-ex" }, { "text": "Study of the photon remnant in resolved photoproduction at HERA: Photoproduction at HERA is studied in $ep$ collisions, with the ZEUS\ndetector, for $\\gamma p$ centre-of-mass energies ranging from 130-270 GeV. A\nsample of events with two high-$p_T$ jets ($p_T > 6$ GeV, $\\eta <1.6$) and a\nthird cluster in the approximate direction of the electron beam is isolated\nusing a clustering algorithm. These events are mostly due to resolved\nphotoproduction. The third cluster is identified as the photon remnant. Its\nproperties, such as the transverse and longitudinal energy flows around the\naxis of the cluster, are consistent with those commonly attributed to jets, and\nin particular with those found for the two jets in these events. The mean value\nof the photon remnant $p_T$ with respect to the beam axis is measured to be\n$2.1 \\pm 0.2$ GeV, which demonstrates substantial mean transverse momenta for\nthe photon remnant.", "category": "hep-ex" }, { "text": "Measurements of differential cross-sections in four-lepton events in 13\n TeV proton-proton collisions with the ATLAS detector: Measurements of four-lepton differential and integrated fiducial\ncross-sections in events with two same-flavour, opposite-charge electron or\nmuon pairs are presented. The data correspond to 139 fb$^{-1}$ of $\\sqrt{s}=13$\nTeV proton-proton collisions, collected by the ATLAS detector during Run 2 of\nthe Large Hadron Collider (2015-2018). The final state has contributions from a\nnumber of interesting Standard Model processes that dominate in different\nfour-lepton invariant mass regions, including single $Z$ boson production,\nHiggs boson production and on-shell $ZZ$ production, with a complex mix of\ninterference terms, and possible contributions from physics beyond the Standard\nModel. The differential cross-sections include the four-lepton invariant mass\ninclusively, in slices of other kinematic variables, and in different lepton\nflavour categories. Also measured are dilepton invariant masses, transverse\nmomenta, and angular correlation variables, in four regions of four-lepton\ninvariant mass, each dominated by different processes. The measurements are\ncorrected for detector effects and are compared with state-of-the-art Standard\nModel calculations, which are found to be consistent with the data. The\n$Z\\rightarrow 4\\ell$ branching fraction is extracted, giving a value of\n$\\left(4.41 \\pm 0.30\\right) \\times 10^{-6}$. Constraints on effective field\ntheory parameters and a model based on a spontaneously broken $B-L$ gauge\nsymmetry are also evaluated. Further reinterpretations can be performed with\nthe provided information.", "category": "hep-ex" }, { "text": "Measurement of the CKM angle $\u03b3$ in the $B^0 \\to DK^{*0}$ channel\n using self-conjugate $D \\to K_S^0 h^+ h^-$ decays: A model-independent study of CP violation in $B^0 \\to DK^{*0}$ decays is\npresented using data corresponding to an integrated luminosity of 9fb$^{-1}$\ncollected by the LHCb experiment at centre-of-mass energies of $\\sqrt{s}=7, \\,\n8$ and $13$TeV. The CKM angle $\\gamma$ is determined by examining the\ndistributions of signal decays in phase-space bins of the self-conjugate $D \\to\nK_S^0 h^+ h^-$ decays, where $h = \\pi, K$.\n Observables related to CP violation are measured and the angle $\\gamma$ is\ndetermined to be $\\gamma=(49^{+ 22}_{-19})^\\circ$. Measurements of the\namplitude ratio and strong-phase difference between the favoured and suppressed\n$B^0$ decays are also presented.", "category": "hep-ex" }, { "text": "Measurement of the CP-Violating Asymmetry Amplitude sin2beta: We present results on time-dependent CP-violating asymmetries in neutral B\ndecays to several CP eigenstates. The measurements use a data sample of about\n88 million Y(4S) --> B Bbar decays collected between 1999 and 2002 with the\nBABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. We study\nevents in which one neutral B meson is fully reconstructed in a final state\ncontaining a charmonium meson and the other B meson is determined to be either\na B0 or B0bar from its decay products. The amplitude of the CP-violating\nasymmetry, which in the Standard Model is proportional to sin2beta, is derived\nfrom the decay-time distributions in such events. We measure sin2beta = 0.741\n+/- 0.067 (stat) +/- 0.034 (syst) and |lambda| = 0.948 +/- 0.051 (stat) +/-\n0.030 (syst). The magnitude of lambda is consistent with unity, in agreement\nwith the Standard Model expectation of no direct CP violation in these modes.", "category": "hep-ex" }, { "text": "Measurement of Transverse Single-Spin Asymmetries for Di-Jet Production\n in Proton-Proton Collisions at $\\sqrt{s} = 200$ GeV: We report the first measurement of the opening angle distribution between\npairs of jets produced in high-energy collisions of transversely polarized\nprotons. The measurement probes (Sivers) correlations between the transverse\nspin orientation of a proton and the transverse momentum directions of its\npartons. With both beams polarized, the wide pseudorapidity ($-1 \\leq \\eta \\leq\n+2$) coverage for jets permits separation of Sivers functions for the valence\nand sea regions. The resulting asymmetries are all consistent with zero and\nconsiderably smaller than Sivers effects observed in semi-inclusive deep\ninelastic scattering (SIDIS). We discuss theoretical attempts to reconcile the\nnew results with the sizable transverse spin effects seen in SIDIS and forward\nhadron production in pp collisions.", "category": "hep-ex" }, { "text": "Genuine Correlations of Like-Sign Particles in Hadronic Z0 Decays: Correlations among hadrons with the same electric charge produced in Z0\ndecays are studied using the high statistics data collected from 1991 through\n1995 with the OPAL detector at LEP. Normalized factorial cumulants up to fourth\norder are used to measure genuine particle correlations as a function of the\nsize of phase space domains in rapidity, azimuthal angle and transverse\nmomentum. Both all-charge and like-sign particle combinations show strong\npositive genuine correlations. One-dimensional cumulants initially increase\nrapidly with decreasing size of the phase space cells but saturate quickly. In\ncontrast, cumulants in two- and three-dimensional domains continue to increase.\nThe strong rise of the cumulants for all-charge multiplets is increasingly\ndriven by that of like-sign multiplets. This points to the likely influence of\nBose-Einstein correlations. Some of the recently proposed algorithms to\nsimulate Bose-Einstein effects, implemented in the Monte Carlo model PYTHIA,\nare found to reproduce reasonably well the measured second- and higher-order\ncorrelations between particles with the same charge as well as those in\nall-charge particle multiplets.", "category": "hep-ex" }, { "text": "Analysis of the decay $D^0\\rightarrow K_{S}^{0} K^{+} K^{-}$: Using a data sample of $2.93~fb^{-1}$ of $e^+e^-$ collisions collected at\n$\\sqrt{s}=3.773 GeV$ in the BESIII experiment, we perform an analysis of the\ndecay $D^0\\rightarrow K_{S}^{0} K^{+} K^{-}$. The Dalitz plot is analyzed using\n$1856\\pm 45$ flavor-tagged signal decays. We find that the Dalitz plot is well\ndescribed by a set of six resonances: $a_0(980)^0$, $a_0(980)^+$, $\\phi(1020)$,\n$a_2(1320)^+$, $a_2(1320)^-$ and $a_0(1450)^-$. Their magnitudes, phases and\nfit fractions are determined as well as the coupling of $a_0(980)$ to\n$K\\bar{K}$, $g_{K\\bar{K}}=3.77\\pm 0.24\\text{(stat.)}\\pm0.35\\text{(sys.)} GeV$.\n The branching fraction of the decay $D^0\\rightarrow K_{S}^{0} K^{+} K^{-}$ is\nmeasured using $11660\\pm 118$ untagged signal decays to be $(4.51\\pm\n0.05\\text{(stat.)}\\pm 0.16\\text{(sys.)})10^{-3}$. Both measurements are limited\nby their systematic uncertainties.", "category": "hep-ex" }, { "text": "alpha_S Evolution from 35 GeV to 202 GeV and Flavour Independence: Determinations of the strong coupling constant alpha_S at centre-of-mass\nenergies of 192 through 202 GeV at LEP are presented. The energy evolution of\nalpha_S is in agreement with the prediction of QCD. The combined investigation\nof\n OPAL and JADE data in the energy range of 35 through 189 GeV yields\nalpha_S(m_Z)=0.1187^{+0.0034}_{-0.0019}. The strenght of the strong coupling is\nflavour independent if quark mass effects are taken into account.", "category": "hep-ex" }, { "text": "Measurement of D*+- Cross Sections and the Charm Contribution to the\n Structure Function of the Proton in Deep Inelastic Scattering at HERA: We present measurements on D*+- production cross sections in deep inelastic\ne+p scattering with 1 D0 pi+ with\nsubsequent decay D0 -> K- pi+ or D0 -> K- pi+ pi+ pi- (+c.c) are used. The\ncross sections are extrapolated to the full kinematic region to determine the\ncharm contribution to the proton structure function.", "category": "hep-ex" }, { "text": "Jet Charge with the ATLAS Detector using $\\sqrt{s}=8$ TeV $pp$ Collision\n Data: The momentum-weighted sum of the charges of tracks associated to a jet\nprovides an experimental handle on the electric charge of fundamental\nstrongly-interacting particles. An overview of a study of this jet charge\nobservable for jets produced in dijet and semileptonic $t\\bar{t}$ events using\n$5.8$ $\\mathrm{fb}^{-1}$ of data with the ATLAS detector at $\\sqrt{s}=8$ TeV is\ndescribed here. In addition to providing a constraint on hadronization models,\njet charge has many possible applications in measurements and searches. The\nmodelling of jet charge and its performance as a charge-tagger are studied in\norder to establish this observable as a tool for future physics analyses.", "category": "hep-ex" }, { "text": "B Physics at D0: The Fermilab Tevatron (p pbar), operating at sqrt(s)=1.96 TeV, is a rich\nsource of B hadrons. The large acceptance in terms of rapidity and transverse\nmomentum of the charged particle tracking system and the muon system make the\nupgraded Run II D0 detector an excellent tool for B physics. In this article,\nwe report on selected physics results based on the first 250 pb^-1 of Run II\ndata. This includes results on the X(3872) state, semileptonic B decays, B\nhadron lifetimes, flavour oscillations, and the rare decay B_s -> mu^+ mu^-.", "category": "hep-ex" }, { "text": "Search for new physics in dijet final states in ATLAS and CMS: Events containing a pair of high energy hadronic jet can provide clear\nsignatures in the search for new physics at high energy hadron colliders. The\nATLAS and CMS experiments collected the data from LHC collisions at $\\sqrt{s}$=\n13 TeV during 2015 and 2016, looking for evidence of new resonances or\ndeviations from the Standard Model predictions. Althoug no hint of new physics\nwas seen, strong limits have been set on the most interesting benchmark models,\nimproving LHC Run1 reach.", "category": "hep-ex" }, { "text": "Measurement of the gluon polarisation at COMPASS: COMPASS experiment measurements of the gluon polarisation in nucleon,\nDeltaG/G are reviewed. Two different approaches based on tagging the Photon\nGluon Fusion process are described. They rely on the open charm meson or\nhigh-p_T hadron pairs detection.", "category": "hep-ex" }, { "text": "Measurement of the transverse momentum distribution of Z/gamma* bosons\n in proton-proton collisions at sqrt(s)=7 TeV with the ATLAS detector: A measurement of the Z/gamma* transverse momentum (p_T^Z)) distribution in\nproton-proton collisions at sqrt(s)=7 TeV is presented using Z/gamma*->e+e- and\nZ/gamma*->mu+mu- decays collected with the ATLAS detector in data sets with\nintegrated luminosities of 35 pb^-1 and 40 pb^-1, respectively. The normalized\ndifferential cross sections are measured separately for electron and muon decay\nchannels as well as for their combination up to p_T^Z of 350 GeV for invariant\ndilepton masses 66 GeV pi+ pi- Upsilon(1S), we deduce a 90% C.L. upper limit of\nB[Upsilon(1S) -> invisible] < 0.39%.", "category": "hep-ex" }, { "text": "A new search for the $K_{L} \\to \u03c0^0 \u03bd\\overline\u03bd$ and $K_{L} \\to\n \u03c0^{0} X^{0}$ decays: We searched for the $CP$-violating rare decay of neutral kaon, $K_{L} \\to\n\\pi^0 \\nu \\overline{\\nu}$, in data from the first 100 hours of physics running\nin 2013 of the J-PARC KOTO experiment. One candidate event was observed while\n$0.34\\pm0.16$ background events were expected. We set an upper limit of\n$5.1\\times10^{-8}$ for the branching fraction at the 90\\% confidence level\n(C.L.). An upper limit of $3.7\\times10^{-8}$ at the 90\\% C.L. for the $K_{L}\n\\to \\pi^{0} X^{0}$decay was also set for the first time, where $X^{0}$ is an\ninvisible particle with a mass of 135 MeV/$c^{2}$.", "category": "hep-ex" }, { "text": "A Compact Beam Stop for a Rare Kaon Decay Experiment: We describe the development and testing of a novel beam stop for use in a\nrare kaon decay experiment at the Brookhaven AGS. The beam stop is located\ninside a dipole spectrometer magnet in close proximity to straw drift chambers\nand intercepts a high-intensity neutral hadron beam. The design process,\ninvolving both Monte Carlo simulations and beam tests of alternative beam-stop\nshielding arrangements, had the goal of minimizing the leakage of particles\nfrom the beam stop and the resulting hit rates in detectors, while preserving\nmaximum acceptance for events of interest. The beam tests consisted of\nmeasurements of rates in drift chambers, scintilation counter hodoscopes, a gas\nthreshold Cherenkov counter, and a lead glass array. Measurements were also\nmade with a set of specialized detectors which were sensitive to low-energy\nneutrons, photons, and charged particles. Comparisons are made between these\nmeasurements and a detailed Monte Carlo simulation.", "category": "hep-ex" }, { "text": "Results of direct dark matter detection with CDEX experiment at CJPL: The China Dark Matter Experiment (CDEX), located at the China Jinping\nUnderground Laboratory (CJPL) whose overburden is about 2400m rock, aims at\ndirect searches of light Weakly Interacting Massive Particles (WIMPs). A\nsingle-element 994-gram p-type point contact (PPC) germanium detector (CDEX-1B)\nruns inside a solid passive shielding system. To achieve lower background, a\nprototype 10kg PPC germanium detector array (CDEX-10), consisting of three\ndetector strings with three germanium crystals each, is directly immersed in\nthe liquid nitrogen. With the energy threshold of 160eV, the limits on\nWIMP-nucleus scattering are set by energy spectra and annual modulation\nanalysis, respectively. Incorporating Migdal effect, the data of CDEX-1B are\nre-analyzed to search sub-GeV WIMPs. Finally, the future plan of CDEX\nexperiment in CJPL-II is introduced.", "category": "hep-ex" }, { "text": "Meeting Tight Frequency Requirement of Rounded Damped Detuned Structure: Following successful design and fabrication of damped detuned structures, the\nR&D for the accelerating structures of the NLC/JLC linear collider project\nproceeded to studies of Rounded Damped Detuned Structure with curved cross\nsection of the cavity shape for increased shunt impedance. The important\nfeatures of the structure are the accurately tuned accelerating mode frequency\nand the distribution of the first dipole modes smooth and close to the design\ndistribution. These requirements were met based on the high-accuracy diamond\nturning with its capability to realize the periphery tolerance of two microns.\nThe lowest dipole mode frequencies scattered by 0.6 MHz RMS. The error in the\naccelerating mode frequency averaged over a structure was 0.1 MHz by applying a\nfeed-forward method.", "category": "hep-ex" }, { "text": "A Measurement of the tau->electron Branching Ratio: The branching ratio for the decay tau->e nue nutau has been measured using Z0\ndecay data collected by the OPAL experiment at LEP. In total 33073 tau->e nue\nnutau candidates were identified from a sample of 186197 selected tau decays,\ngiving a branching ratio of 17.81 +- 0.09(stat) +_ 0.06(sys)%. This result is\ncombined with other measurements to test e-mu and mu-tau universality in\ncharged-current weak interactions. Additionally, the strong coupling constant\nalpha_s has been extracted and evolved to the Z0 mass scale, giving alpha_s =\n0.1204 +- 0.0011(exp) +- 0.0019(theory).", "category": "hep-ex" }, { "text": "Photoproduction of Dijets with High Transverse Momenta at HERA: Differential dijet cross sections are measured in photoproduction in the\nregion of photon virtualities Q^2 < 1 GeV^2 with the H1 detector at the HERA ep\ncollider using an integrated luminosity of 66.6 pb^{-1}. Jets are defined with\nthe inclusive k_T algorithm and a minimum transverse momentum of the leading\njet of 25 GeV is required. Dijet cross sections are measured in direct and\nresolved photon enhanced regions separately. Longitudinal proton momentum\nfractions up to 0.7 are reached. The data compare well with predictions from\nMonte Carlo event generators based on leading order QCD and parton showers and\nwith next-to-leading order QCD calculations corrected for hadronisation\neffects.", "category": "hep-ex" }, { "text": "Indirect CP violation results and HFAG averages: The current status of the search for indirect CP violation in the neutral D\nmeson system at the B-factories and at LHCb is reported. The indirect CP\nasymmetry search is performed by the measurement of the proper-time asymmetry\n($A_{\\Gamma}$) in decays of $D^0-\\bar{D^0}$ mesons to CP eigenstates, $K^-K^+$\nand $\\pi^- \\pi^+$, and by $y_{CP}$, the ratio between the effective lifetime\nmeasured in decay to a CP eigenstate and that to the mixed eigenstate $K \\pi$.\nAll results are consistent with the no CP violation hypothesis. The latest\nworld averages for mixing and CP asymmetry in the charm sector evaluated by the\nHeavy Flavour Averaging Group are presented. The no mixing hypothesis is\nexcluded at more than 12 standard deviations. The search for direct and\nindirect CP violation in the charm sector is consistent with no CP violation at\n2.0% confident level.", "category": "hep-ex" }, { "text": "Highlight: Forward Physics (LHCf + FASER): The LHC Run III will be a crucial run for the two LHC forward experiments:\nLHCf and FASER. In particular, Run III will be the last run where the LHCf\ndetector can operate and, at the same time, the first run of the new FASER\nproject. The LHCf experiment is dedicated to precise measurements of forward\nproduction, necessary to tune hadronic interaction models employed in\ncosmic-ray physics. In Run III, the experiment will accomplish two fundamental\ngoals: operating in p-p collisions at $\\sqrt{s} = $ 14 TeV, it will acquire a\nten times larger statistics respect to Run II, in order to have precise\nmeasurements of $\\pi^{0}$ production; operating in high energy p-O and O-O\ncollisions, it will measure forward production in a configuration that is very\nsimilar to the first interaction of an Ultra High Energy Cosmic Ray with an\natmospheric nucleus. The FASER experiment is dedicated to the search of new\nweakly-interacting light particles, thanks to a forward detector with proper\nshielding from Standard Model background. In Run III, the experiment will\nsearch for new particles with a good sensitivity, which can be strongly\nimproved by a following possible upgrade before HL-LHC. In addition, thanks to\nthe dedicated FASER$\\nu$ detector, the experiment will measure neutrino\nproduction at a collider for the first time. In this contribution, we discuss\nthe main results expected from the LHCf and FASER experiments in Run III,\nhighlighting their fundamental contribution in research fields that are not\naccessible to the four large LHC experiments.", "category": "hep-ex" }, { "text": "Emerging Computing Technologies in High Energy Physics: While in the early 90s High Energy Physics (HEP) lead the computing industry\nby establishing the HTTP protocol and the first web-servers, the long\ntime-scale for planning and building modern HEP experiments has resulted in a\ngenerally slow adoption of emerging computing technologies which rapidly become\ncommonplace in business and other scientific fields. I will overview some of\nthe fundamental computing problems in HEP computing and then present the\ncurrent state and future potential of employing new computing technologies in\naddressing these problems.", "category": "hep-ex" }, { "text": "Transition to the region of central collisions: The experimental results on the behaviour of the characteristics of secondary\nparticles depending on the disintegration degree of nuclei are used to\ndetermine the region of central collisions. It was therefore possible that : -\nthe correlation between the prosesses of total disintegration of nuclei and the\ncentral collisions of nuclei had been shown; - the existence of the regime\nchange points in the behaviour of the considered characteristics of secondary\nparticles depending on the disintegration degree of nuclei had been observed in\nthe other earlier experiments as well. The number of all protons in\n12CC-interactions at the momentum of 4.2 A GeV/c obtained from the 2-m propane\nbubble chamber exposed at the Dubna machine is considered as a disintegration\ndegree of nuclei. The experimental results demonstrate that there are cases\ncorresponding to the critical phenomena among the events with the central\ncollisions of nuclei. For 12CC-interaction the behaviour of the number of the\nevents, depending on Q also depends on the number of fragments and has a\ntwo-steps form. This result could be explained by the existence of nuclear\nclusters. The experimental results on the relation between the number of\nevents, the angular distributions of protons and full number of protons are\npresented for 12CC-interactions at the momentum of 4.2 A GeV/c. The influence\nof nuclear fragmentation process on the results is also considered. The\nobtained results confirm the assumption that there exist the critical phenomena\namong the central collisions and it is necessary to use a percolation approach\nfor the full description of the central collisions.", "category": "hep-ex" }, { "text": "Towards Designing and Exploiting Generative Networks for Neutrino\n Physics Experiments using Liquid Argon Time Projection Chambers: In this paper, we show that a hybrid approach to generative modeling via\ncombining the decoder from an autoencoder together with an explicit generative\nmodel for the latent space is a promising method for producing images of\nparticle trajectories in a liquid argon time projection chamber (LArTPC).\nLArTPCs are a type of particle physics detector used by several current and\nfuture experiments focused on studies of the neutrino. We implement a\nVector-Quantized Variational Autoencoder (VQ-VAE) and PixelCNN which produces\nimages with LArTPC-like features and introduce a method to evaluate the quality\nof the images using a semantic segmentation that identifies important\nphysics-based features.", "category": "hep-ex" }, { "text": "Mini-review of rare charmonium decays at BESIII: Recently, LHCb experiment announced a 3.5$\\sigma$ evidence for direct CP\nviolation in $D^0$ decay by looking at the difference between\n$A_{CP}(D^0\\rightarrow K^+K^-)$ and $A_{CP}(D^0\\rightarrow \\pi^+\\pi^-)$. This\nis the first evidence of CP violation in charm system, which may indicate new\nphysics beyond the Standard Model. Motivated by this measurement, we review\nrare processes in charmonium decay, especially, the weak decay, $C$ or $P$\nviolated decay and lepton flavor violated decays. In case the new physics\nappears in charm sector, these rare decays of charmonium states will provide\nopportunity to search for significant contributions from physics beyond the\nStandard Model. With huge $J/\\psi$ and $\\psi(2S)$ samples in BESIII experiment,\nthe rare decays may be feasible.", "category": "hep-ex" }, { "text": "Jet Results and Jet Reconstruction Techniques in p+p and their Prospects\n in Pb+Pb Collisions in CMS: Copious production of very energetic jets is expected at the LHC due to the\nlarge increase in collision energy. Jet reconstruction at these high center of\nmass energies will provide crucial leverage to map out the QCD evolution of\nparton energy loss and a unique insight into the nature of the hot QCD matter.\nThis article presents jet reconstruction techniques and the preliminary jet\nresults in p+p collisions at $\\sqrt{s}=7$ TeV collected by the CMS experiment\nat the LHC. Jet reconstruction prospects for the heavy ion collisions are also\ndiscussed.", "category": "hep-ex" }, { "text": "Improved measurement of $\u03c8(2S)$ decays into $\u03c4^{+}\u03c4^{-}$: Using 14M $\\psi (2S)$ events collected at BESII, the branching fraction of\n$\\psi (2S)\\to \\tau ^{+}\\tau ^{-}$ is measured to be $Br_{\\tau \\tau}=(3.10\\pm\n0.21\\pm 0.38)\\times 10^{-3}$, where the first error is statistical and the\nsecond is systematic.", "category": "hep-ex" }, { "text": "The CMS Experiment: Status and First Results: After nearly two decades of design, construction and commissioning, the CMS\ndetector was operated with colliding LHC proton beams for the first time in\nNovember 2009. Collision data were recorded at centre-of-mass energies of 0.9\nand 2.36 TeV, and analyzed with a fast turn-around time by the CMS\ncollaboration. In this talk I will present a selection of commissioning results\nand striking first physics resonances observed. Then I will discuss the\nanalysis of the transverse momentum and rapidity distribution of charged\nhadrons, which led to the first CMS physics publication. The excellent\nperformance of the CMS detector and agreement with predictions from simulation\nare impressive for a collider detector at startup and show a great potential\nfor discovery physics in the upcoming LHC run.", "category": "hep-ex" }, { "text": "Measurement of the Branching Fractions for Inclusive $B^-$ and $\\bar\n B^0$ Decays to Flavor-tagged $D$, $D_s$ and $\u039b_c$: We report on the inclusive branching fractions of $B^-$ and of ${\\bar B}^0$\nmesons decaying to ${D^0 X}$, ${{\\bar D}^0 X}$, ${D^+ X}$, ${D^- X}$, ${D_s^+\nX}$, ${D_s^- X}$, ${\\Lambda_c^+ X}$, ${{\\bar \\Lambda}_c^- X}$, based on a\nsample of 88.9 million $B \\bar B$ events recorded with the $BABAR$ detector at\nthe $\\Upsilon(4S)$ resonance. Events are selected by completely reconstructing\none $B$ and searching for a reconstructed charmed particle in the rest of the\nevent. We measure the number of charmed and of anti-charmed particles per $B$\ndecay and derive the total charm yield per $B^-$ decay, $n_c^- = 1.313 \\pm\n0.037 \\pm 0.062 ^{+0.063}_{-0.042} $, and per ${\\bar B}^0$ decay, $n_c^0 =\n1.276 \\pm 0.062 \\pm 0.058 ^{+0.066}_{-0.046}$ where the first uncertainty is\nstatistical, the second is systematic, and the third reflects the charm\nbranching-fraction uncertainties.", "category": "hep-ex" }, { "text": "Measurement of the solar neutrino energy spectrum using\n neutrino-electron scattering: A measurement of the energy spectrum of recoil electrons from solar neutrino\nscattering in the Super--Kamiokande detector is presented. The results shown\nhere are obtained from 504 days of data taken between the 31st of May, 1996 and\nthe 25th of March, 1998. The shape of the measured spectrum is compared with\nthe expectation for solar B8 neutrinos. The comparison takes into account both\nkinematic and detector related effects in the measurement process. The spectral\nshape comparison between the observation and the expectation gives a chi-square\nof 25.3 with 15 degrees of freedom, corresponding to a 4.6% confidence level.", "category": "hep-ex" }, { "text": "Search for single top quark production in ppbar collisions at\n sqrt(s)=1.96 TeV: We present a search for electroweak production of single top quarks in the\ns-channel and t-channel using neural networks for signal-background separation.\nWe have analyzed 230 pb$^{-1}$ of data collected with the D0 detector at the\nFermilab Tevatron Collider at a center-of-mass energy of 1.96 TeV and find no\nevidence for a single top quark signal. The resulting 95% confidence level\nupper limits on the single top quark production cross sections are 6.4 pb in\nthe s-channel and 5.0 pb in the t-channel.", "category": "hep-ex" }, { "text": "Measurement of spin correlation in ttbar production using dilepton final\n states: We measure the correlation between the spin of the top quark and the spin of\nthe anti-top quark in (ttbar -> W+ W- b bbar -> l+ nu b l- nubar bbar) final\nstates produced in ppbar collisions at a center of mass energy sqrt(s)=1.96\nTeV, where l is an electron or muon. The data correspond to an integrated\nluminosity of 5.4 fb-1 and were collected with the D0 detector at the Fermilab\nTevatron collider. The correlation is extracted from the angles of the two\nleptons in the t and tbar rest frames, yielding a correlation strength C=\n0.10^{+0.45}_{-0.45}, in agreement with the NLO QCD prediction within two\nstandard deviations, but also in agreement with the no correlation hypothesis.", "category": "hep-ex" }, { "text": "Charmonia production in ALICE: Quarkonia states are expected to provide essential information on the\nproperties of the high-density strongly-interacting system formed in the early\nstages of high-energy heavy-ion collisions. ALICE is the LHC experiment\ndedicated to the study of nucleus-nucleus collisions and can study charmonia at\nforward rapidity (2.5 < y < 4) via the mu+ mu- decay channel and at mid\nrapidity (|y| < 0.9) via the e+ e- decay channel. In both cases charmonia are\nmeasured down to zero transverse momentum. The inclusive J/psi production as a\nfunction of transverse momentum and rapidity in pp collisions at sqrt{s} = 2.76\nand 7 TeV are presented. For pp collisions at sqrt{s} = 7 TeV, the inclusive\nJ/psi production as a function of the charged particle multiplicity, the\ninclusive J/psi polarization at forward rapidity and the J/psi prompt to\nnon-prompt fraction are discussed. Finally, the analysis of the inclusive J/psi\nproduction in the Pb-Pb data collected fall 2011 at a center of mass energy of\nsqrt{s_{NN}} = 2.76 TeV is presented. Results on the nuclear modification\nfactor are then shown as a function of centrality, transverse momentum and\nrapidity and compared to model predictions. First results on inclusive J/psi\nelliptic flow are given.", "category": "hep-ex" }, { "text": "Measurement of final-state correlations in neutrino muon-proton\n mesonless production on hydrocarbon at $\\langle E_\u03bd\\rangle=3$ GeV: Final-state kinematic imbalances are measured in mesonless production of\n$\\nu_\\mu + A \\to \\mu^- + p + X$ in the MINERvA tracker. Initial- and\nfinal-state nuclear effects are probed using the direction of the $\\mu^-$-p\ntransverse momentum imbalance and the initial-state momentum of the struck\nneutron. Differential cross sections are compared to predictions based on\ncurrent approaches to medium modeling. These models under-predict the cross\nsection at intermediate intranuclear momentum transfers that generally exceed\nthe Fermi momenta. As neutrino interaction models need to correctly incorporate\nthe effect of the nucleus in order to predict neutrino energy resolution in\noscillation experiments, this result points to a region of phase space where\nadditional cross section strength is needed in current models, and demonstrates\na new technique that would be suitable for use in fine grained liquid argon\ndetectors where the effect of the nucleus may be even larger.", "category": "hep-ex" }, { "text": "Jet charge identification in ee-Z-qq process at Z pole operation: Accurate jet charge identification is essential for precise electroweak and\nflavor measurements at the high-energy frontier. We propose a novel method\ncalled the Leading Particle Jet Charge method (LPJC) to determine the jet\ncharge based on information about the leading charged particle. Tested on Z -\nbb and Z - cc samples at a center-of-mass energy of 91.2GeV, the LPJC achieves\nan effective tagging power of 20%/9% for the c/b jet, respectively. Combined\nwith the Weighted Jet Charge method (WJC), we develop a Heavy Flavor Jet Charge\nmethod (HFJC), which achieves an effective tagging power of 39%/20% for c/b\njet, respectively. This paper also discusses the dependencies between jet\ncharge identification performance and the fragmentation process of heavy flavor\njets, and critical detector performances.", "category": "hep-ex" }, { "text": "Spin-Parity Analysis of ppbar Mass Threshold Structure in J/psi and psi'\n Radiative Decays: A partial wave analysis of the $p \\bar{p}$ mass-threshold enhancement in the\nreaction $J/\\psi\\rightarrow\\gamma p\\bar{p}$ is used to determine: its $J^{PC}$\nquantum numbers to be $0^{-+}$; its peak mass to be below threshold at\n$M=1832^{+19}_{-5} {\\rm(stat.)}^{+18}_{-17} {\\rm (syst.)}\\pm19 {\\rm (model)}\n{\\rm MeV}/c^2$; and its total width to be $\\Gamma<76 {\\rm MeV}/c^2$ at the 90%\nC.L. The product branching ratio is measured to be $B(J/\\psi\\rightarrow\\gamma\nX(p\\bar{p}))B(X(p\\bar{p})\\rightarrow p\\bar{p})=(9.0^{+0.4}_{-1.1} {\\rm\n(stat.)}^{+1.5}_{-5.0} {\\rm (syst.)}\\pm2.3 {\\rm (model)})\\times10^{-5}$. A\nsimilar analysis performed on $\\psi^\\prime\\rightarrow\\gamma p\\bar{p}$ decays\nshows, for the first time, the presence of a corresponding enhancement with a\nproduction rate relative to that for $J/\\psi$ decays of\n$R=(5.08^{+0.71}_{-0.45} {\\rm (stat.)}^{+0.67}_{-3.58} {\\rm (syst.)}\\pm0.12\n{\\rm (model)})%$.", "category": "hep-ex" }, { "text": "Precision Electroweak Measurements at FCC-ee: The prospects for electroweak precision measurements at the Future Circular\nCollider with electron-positron beams (FCC-ee) are discussed. The Z mass and\nwidth, as well as the value of the electroweak mixing angle, can be measured\nwith very high precision at the Z pole thanks to an instantaneous luminosity\nfive to six order of magnitudes larger than LEP. At centre-of-mass energies\naround 160 GeV, corresponding to the WW production threshold, the W mass can be\ndetermined very precisely with high-statistics cross section measurements at\nseveral energy points. Similarly, a very precise determination of the top mass\ncan be provided by an energy scan at the $\\mathrm{t \\bar t}$ production\nthreshold, around 350 GeV.", "category": "hep-ex" }, { "text": "Search for lepton flavor violating $\u03c4\\to \\ell V^0$ decays at Belle: We have searched for neutrinoless $\\tau$ lepton decays into $\\ell$ and $V^0$,\nwhere $\\ell$ stands for an electron or muon, and $V^0$ for a vector meson\n($\\phi$, $\\omega$, $K^{*0}$ or $\\bar{K}^{*0}$), using 543 fb$^{-1}$ of data\ncollected with the Belle detector at the KEKB asymmetric-energy $e^+e^-$\ncollider. No excess of signal events over the expected background is observed,\nand we set upper limits on the branching fractions in the range $(0.7 - 1.8)\n\\times 10^{-7}$ at the 90% confidence level. These upper limits include the\nfirst results for $\\ell \\omega$ as well as new limits that are $3.6 - 9.6$\ntimes more restrictive than our previous results for $\\ell \\phi$, $\\ell K^{*0}$\nand $\\ell \\bar{K}^{*0}$.", "category": "hep-ex" }, { "text": "Vector Boson Fusion Higgs Production at the LHC - Mass Variables: There exist substantial backgrounds to the vector boson fusion production of\nHiggs at the LHC. Mass variables are studied which may alleviate the need to\nassume a spin zero WW resonance in order to achieve a sufficient signal to\nnoise ratio in the two jet plus two lepton and missing energy final state.", "category": "hep-ex" }, { "text": "Measurements of t t-bar spin correlations and top-quark polarization\n using dilepton final states in pp collisions at sqrt(s) = 7 TeV: Spin correlations in the top quark-antiquark system and the polarization of\nthe top quark are measured using dilepton final states produced in pp\ncollisions at the LHC at sqrt(s) = 7 TeV. The data correspond to an integrated\nluminosity of 5.0 inverse femtobarns collected with the CMS detector. The\nmeasurements are performed using events with two oppositely charged leptons\n(electrons or muons), a significant imbalance in transverse momentum, and two\nor more jets, where at least one of the jets is identified as originating from\na b quark. The spin correlations and polarization are measured through\nasymmetries in angular distributions of the two selected leptons, unfolded to\nthe parton level. All measurements are found to be in agreement with\npredictions of the standard model.", "category": "hep-ex" }, { "text": "High-statistics measurement of neutral-pion pair production in\n two-photon collisions: We present a high-statistics measurement of differential cross sections and\nthe total cross section for the process gamma gamma -> pi^0 pi^0 in the\nkinematic range 0.6 GeV <= W <= 4.0 GeV and |cos theta*| <= 0.8, where W and\ntheta* are the energy and pion scattering angle, respectively, in the gamma\ngamma center-of-mass system. Differential cross sections are fitted to obtain\ninformation on S, D_0, D_2, G_0 and G_2 waves. The G waves are important above\nW ~= 1.6 GeV. General behavior of partial waves is studied by fitting\ndifferential cross sections in a simple parameterization where amplitudes\ncontain resonant contributions and smooth background. The D_2 wave is dominated\nby the f_2(1270) meson whose parameters are consistent with the with the\ncurrent world averages. The D_0 wave contains a f_2(1270) component, whose\nfraction is fitted. For the S wave, the f_0(980) parameters are found to be\nconsistent with the values determined from our recent pi^+ pi^- data. In\naddition to the f_0(980), the S wave prefers to have another resonance-like\ncontribution whose parameters are obtained.", "category": "hep-ex" }, { "text": "Measurement of the $B^0$--$\\bar B^0$ oscillation frequency $\u0394m_d$\n with the decays $B^0 \\to D^- \u03c0^+$ and $B^0 \\to J/ \u03c8K^{*0}$: The $B^0$--$\\bar B^0$ oscillation frequency $\\Delta m_d$ is measured by the\nLHCb experiment using a dataset corresponding to an integrated luminosity of\n$1.0\\,$fb$^{-1}$ of proton-proton collisions at $\\sqrt{s} = 7\\,$TeV, and is\nfound to be $\\Delta m_d = 0.5156 \\pm 0.0051\\,($stat.$) \\pm\n0.0033\\,($syst.$)\\,$ps$^{-1}$. The measurement is based on results from\nanalyses of the decays $B^0 \\to D^- \\pi^+$ ($D^- \\to K^+ \\pi^- \\pi^-$) and $B^0\n\\to J/ \\psi K^{*0}$ ($ J/ \\psi \\to \\mu^+ \\mu^-$, $K^{*0} \\to K^+ \\pi^-$) and\ntheir charge conjugated modes.", "category": "hep-ex" }, { "text": "Measurements of Parity-Violation Parameters at SLD: We present direct measurements of the parity-violation parameters $A_b$,\n$A_c$, and $A_s$ at the $Z^0$ resonance with the SLD detector. The measurements\nare based on approximately 530k hadronic $Z^0$ events collected in 1993-98.\nObtained results are $A_b = 0.914\\pm0.024$ (SLD combined: preliminary), $A_c =\n0.635\\pm0.027$ (SLD combined: preliminary), and $A_s = 0.895\\pm0.066(stat.)\\pm\n0.062(sys.)$.", "category": "hep-ex" }, { "text": "Searches for Extra Spatial Dimensions with the CMS Detector at the LHC: The success of the first three years of operations of the LHC at\ncenter-of-mass energies of 7 and 8 TeV radically changed the landscape of\nsearches for new physics beyond the standard model and our very way of thinking\nabout its possible origin and its hiding place. Among the paradigms of new\nphysics that have been probed quite extensively at the LHC, are various models\nthat predict the existence of extra spatial dimensions. In this review, the\ncurrent status of searches for extra dimensions with the CMS detector is\npresented, along with prospects for future searches at the full energy of the\nLHC, expected to be reached in the next few years.", "category": "hep-ex" }, { "text": "Search for the Rare Decays J/Psi --> Ds- e+ nu_e, J/Psi --> D- e+ nu_e,\n and J/Psi --> D0bar e+ e-: We report on a search for the decays J/Psi --> Ds- e+ nu_e + c.c., J/Psi -->\nD- e+ nu_e + c.c., and J/Psi --> D0bar e+ e- + c.c. in a sample of 5.8 * 10^7\nJ/Psi events collected with the BESII detector at the BEPC. No excess of signal\nabove background is observed, and 90% confidence level upper limits on the\nbranching fractions are set: B(J/Psi --> Ds- e+ nu_e + c.c.)<4.8*10^-5, B(J/Psi\n--> D- e+ nu_e + c.c.)<1.2*10^-5, and B(J/Psi --> D0bar e+ e- + c.c.)<1.1*10^-5", "category": "hep-ex" }, { "text": "Midrapidity antiproton-to-proton ratio in pp collisions at $\\sqrt{s} =\n 0.9$ and $7$ TeV measured by the ALICE experiment: The ratio of the yields of antiprotons to protons in pp collisions has been\nmeasured by the ALICE experiment at $\\sqrt{s} = 0.9$ and $7$ TeV during the\ninitial running periods of the Large Hadron Collider(LHC). The measurement\ncovers the transverse momentum interval $0.45 < p_{\\rm{t}} < 1.05$ GeV/$c$ and\nrapidity $|y| < 0.5$. The ratio is measured to be $R_{|y| < 0.5} = 0.957 \\pm\n0.006 (stat.) \\pm 0.014 (syst.)$ at $0.9$ TeV and $R_{|y| < 0.5} = 0.991 \\pm\n0.005 (stat.) \\pm 0.014 (syst.)$ at $7$ TeV and it is independent of both\nrapidity and transverse momentum. The results are consistent with the\nconventional model of baryon-number transport and set stringent limits on any\nadditional contributions to baryon-number transfer over very large rapidity\nintervals in pp collisions.", "category": "hep-ex" }, { "text": "Exclusive $\u03c0^+\u03c0^-$ Production at the LHC with Forward Proton Tagging: A process of Central Exclusive $\\pi^+\\pi^-$ production in proton-proton\ncollisions and its theoretical description is presented. A possibility of its\nmeasurement, during the special low luminosity LHC runs, with the help of the\nATLAS central detector for measuring pions and the ALFA stations for tagging\nthe scattered protons is studied. A visible cross section is estimated to be 21\n$\\mu$b for $\\sqrt{s}=7$ TeV, which gives over 2000 events for 100 $\\mu$b$^{-1}$\nof integrated luminosity. Differential distributions in pion pseudorapidities,\npion and proton transverse momenta as well as $\\pi^+\\pi^-$ invariant mass are\nshown and discussed.", "category": "hep-ex" }, { "text": "Inclusive Jet Production in DIS at High Q^2 and Extraction of the Strong\n Coupling: Inclusive jet production is studied in neutral current deep-inelastic\npositron-proton scattering at large four momentum transfer squared Q^2>150\nGeV^2 with the H1 detector at HERA. The measurements are found to be well\ndescribed by calculations at next-to-leading order in perturbative QCD.\n The running of the strong coupling is demonstrated and the value of\nalpha_s(M_Z) is determined.", "category": "hep-ex" }, { "text": "CP Violation in B Decays at the Tevatron: Between 1992 to 1996, the CDF and D0 detectors each collected data samples\nexceeding 100 pb^{-1} of p\\bar{p} collisions at sqrt{s}=1.8 TeV at the Fermilab\nTevatron. These data sets led to a large number of precision measurements of\nthe properties of B hadrons including lifetimes, masses, neutral B meson flavor\noscillations, and relative branching fractions, and to the discovery of the B_c\nmeson. Perhaps the most exciting result was the first look at the CP violation\nparameter sin(2beta) using the world's largest sample of fully reconstructed\nB^0/bar{B}^0 -> J/psi K^0_S decays. A summary of this result is presented here.\nIn the year 2000, the Tevatron will recommence p\\bar{p} collisions with an over\norder of magnitude expected increase in integrated luminosity (1 fb^{-1} per\nyear). The CDF and D0 detectors will have undergone substantial upgrades,\nparticularly in the tracking detectors and the triggers. With these\nenhancements, the Tevatron B physics program will include precision\nmeasurements of sin(2beta) and B^0_s flavor oscillations, as well as studies of\nrare B decays that are sensitive to new physics. The studies of B^0_s mesons\nwill be particularly interesting as this physics will be unique to the Tevatron\nduring the first half of the next decade.", "category": "hep-ex" }, { "text": "Measurement of b-jet Shapes in Inclusive Jet Production in p pbar\n Collisions at sqrt{s} = 1.96 TeV: We present a measurement of the shapes of b-jets using 300 pb-1 of data\nobtained with the upgraded Collider Detector at Fermilab (CDF II) in p pbar\ncollisions at center of mass energy sqrt{s}=1.96 TeV. This measurement covers a\nwide transverse momentum range, from 52 to 300 GeV/c. Samples of heavy-flavor\nenhanced jets together with inclusive jets are used to extract the average\nshapes of b-jets. The b-jets are expected to be broader than inclusive jets.\nMoreover, b-jets containing a single b-quark are expected to be narrower than\nthose containing a b bbar pair from gluon splitting. The measured b-jet shapes\nare found to be significantly broader than expected from the PYTHIA and HERWIG\nMonte Carlo simulations. This effect may arise from an underestimation of the\nfraction of b-jets originating from gluon splitting in these simulations.", "category": "hep-ex" }, { "text": "Identification of boosted Higgs bosons decaying into $b$-quark pairs\n with the ATLAS detector at 13 TeV: This paper describes a study of techniques for identifying Higgs bosons at\nhigh transverse momenta decaying into bottom-quark pairs, $H \\rightarrow\nb\\bar{b}$, for proton-proton collision data collected by the ATLAS detector at\nthe Large Hadron Collider at a centre-of-mass energy $\\sqrt{s}=13$ TeV. These\ndecays are reconstructed from calorimeter jets found with the anti-$k_{t}$ $R =\n1.0$ jet algorithm. To tag Higgs bosons, a combination of requirements is used:\n$b$-tagging of $R = 0.2$ track-jets matched to the large-$R$ calorimeter jet,\nand requirements on the jet mass and other jet substructure variables. The\nHiggs boson tagging efficiency and corresponding multijet and hadronic\ntop-quark background rejections are evaluated using Monte Carlo simulation.\nSeveral benchmark tagging selections are defined for different signal\nefficiency targets. The modelling of the relevant input distributions used to\ntag Higgs bosons is studied in 36 fb$^{-1}$ of data collected in 2015 and 2016\nusing $g\\to b\\bar{b}$ and $Z(\\rightarrow b\\bar{b})\\gamma$ event selections in\ndata. Both processes are found to be well modelled within the statistical and\nsystematic uncertainties.", "category": "hep-ex" }, { "text": "Search for Hidden Photon Dark Matter Using a Multi-Cathode Counter: A search for hidden-photon (HP) dark matter using a multi-cathode counter is\nreported. The technique based on counting of single electrons emitted from\nouter cathode of the proportional counter by hidden-photons was used. The\napparatus and the calibration of the counter by ultraviolet lamp are described.\nIt is shown that this technique attains a maximum sensitivity in the energy\nrange of Vacuum Ultraviolet. From the results of measurements we set an upper\nlimit on the photon-HP mixing parameter \\chi. A further progress of using a\nmulti-cathode technique is discussed.", "category": "hep-ex" }, { "text": "Observation of $B^+ \\to \u03c7_{c0} K^+ $: We report the first observation of the decay $B^+ \\to \\chi_{c0} K^+$ using\n21.3 fb$^{-1}$ of data collected by the Belle detector at the $\\Upsilon$(4S)\nresonance. The preliminary result for the branching fraction is\n${\\cal{B}}(B^+\\to \\chi_{c0}K^+)=(8.0^{+2.7}_{-2.4}\\pm 1.0\\pm 1.1)\\times\n10^{-4}$ where the first error is statistical, the second is systematic, and\nthe third comes from the uncertainty in the $\\chi_{c0}\\to\\pi^+\\pi^-$ branching\nfraction.", "category": "hep-ex" }, { "text": "Measurement of the CP-violating phase \u03c6_s^{J/\u03c8\u03c6} at D0: This paper is a report of an updated measurement of the CP-violating phase\nand the decay width difference for the two mass eigenstates from flavor-tagged\ndecay Bs0 to J/psi phi}. The 68% confidence level intervals, including\nsystematic uncertainties, are phi_s=-0.55 ^{+0.38}_{-0.36}$ and \\Delta \\Gamma_s\n= 0.163 ^{+0.065}_{-0.064}$ ps^{-1}. This measurement is in agreement with SM\nexpected value, the p-value for the Standard Model point is 29.8%. The data\nsample corresponds to an integrated luminosity of 8.0 fb^{-1} accumulated with\nthe D0 detector at the Fermilab Tevatron collider.", "category": "hep-ex" }, { "text": "Inclusive production of $W$ in pp Collisions in a range of\n center-of-mass energy from 7 to 100 TeV: The proton-proton collision energy at Large Hadron Collider (LHC) has been 7,\n8 and 13 TeV recently with the goal of reaching to 14 TeV which is the maximum\ncapacity of the LHC. However, there is still more physics yet to be explored\nand tested beyond the energy regime of the LHC to reach new discoveries.\nTherefore, a new collider bigger than the LHC machine, which will be able to\ncollide protons at 100 TeV center-of-mass energy, is under consideration by the\nhigh-energy physics community. To provide an insight to the transition from LHC\nto 100 TeV collider, some properties of W processes are investigated in a range\nof collision energy from 7 to 100 TeV using HERAPDF2.0, MMHT2014, NNPDF3.1 and\nCT14 NNLO PDF models at NNLO QCD. The considered properties are the production\nrates of W, the change of uncertainties (PDF, renormalization and factorization\nscales, strong coupling constant, model and parameterization), and W boson\nlepton charge asymmetry.", "category": "hep-ex" }, { "text": "Searches for the Supersymmetric Partner of the Bottom Quark: We have performed a search for the scalar bottom quark from gluino decays in\nan R-parity conserving SUSY scenario with m(gluino) > m(sbottom), by\ninvestigating a final state of large missing transverse energy, with three or\nmore jets, and some of them from the hadronization of b-quarks. A data sample\nof 156pb-1 collected by the Collider Detector at Fermilab at a center-of-mass\nenergy of 1.96TeV was used. For the final selection, jets containing secondary\ndisplaced vertices were required. This analysis has been performed 'blind', in\nthat the inspection of the signal region was only made after the standard model\nprediction was fina lized. Comparing data with SUSY predictions, we can exclude\nmasses of the gluino and sbottom of up to 280 and 240GeV/c^2 respectively.", "category": "hep-ex" }, { "text": "Real and Virtual Photon Structure at HERA: The structure of real and virtual photons has been studied in ep collisions\nat HERA using dijet production. Measurements of differential dijet cross\nsections as function of the fraction of photon's momentum invested in the dijet\nsystem are presented. The dependence of the cross sections on the virtuality of\nthe photon and mean transverse energy squared of the two leading jets has been\ninvestigated. QCD calculations based on current parametrizations of the real\nand virtual photon parton distribution functions have been compared to the\ndata.", "category": "hep-ex" }, { "text": "A Non-parametric Approach to Measuring the \\kpi{} Amplitudes in\n \\dpkkpi{} Decay: Using a large sample of \\dpkkpi{} decays collected by the FOCUS\nphotoproduction experiment at Fermilab, we present the first non-parametric\nanalysis of the \\kpi{} amplitudes in \\dpkkpi{} decay. The technique is similar\nto the technique used for our non-parametric measurements of the \\krzmndk{}\nform factors. Although these results are in rough agreement with those of E687,\nwe observe a wider S-wave contribution for the \\ksw{} contribution than the\nstandard, PDG \\cite{pdg} Breit-Wigner parameterization. We have some weaker\nevidence for the existence of a new, D-wave component at low values of the $K^-\n\\pi^+$ mass.", "category": "hep-ex" }, { "text": "Results from LHCf Experiment: The LHCf experiment has taken data in 2009 and 2010 p-p collisions at LHC at\n$\\sqrt{s} = 0.9$ TeV and $\\sqrt{s} = 7$ TeV. The measurement of the forward\nneutral particle spectra produced in proton-proton collisions at LHC up to an\nenergy of 14 TeV in the center of mass system are of fundamental importance to\ncalibrate the Monte Carlo models widely used in the high energy cosmic ray\n(HECR) field, up to an equivalent laboratory energy of the order of $10^{17}$\neV. In this paper the first results on the inclusive photon spectrum measured\nby LHCf is reported. Comparison of this spectrum with the model expectations\nshow significant discrepancies, mainly in the high energy region. In addition,\nperspectives for future analyses as well as the program for the next data\ntaking period, in particular the possibility to take data in p-Pb collisions,\nwill be discussed.", "category": "hep-ex" }, { "text": "Tests of the Electroweak Symmetry Breaking Sector at the Tevatron: The phenomenology of the electroweak symmetry breaking sector is expected to\ninvolve resonances decaying preferentially into heavy fermions. Three recent\nCDF analyses are reviewed and used to constrain Higgs and Technicolor models.", "category": "hep-ex" }, { "text": "A search for a doubly-charged Higgs boson in pp collisions at sqrt(s) =\n 7 TeV: A search for a doubly-charged Higgs boson in pp collisions at sqrt(s) = 7 TeV\nis presented. The data correspond to an integrated luminosity of 4.9 inverse\nfemtobarns, collected by the CMS experiment at the LHC. The search is performed\nusing events with three or more isolated charged leptons of any flavor, giving\nsensitivity to the decays of pair-produced triplet components Phi[++]Phi[--],\nand Phi[++]Phi[-] from associated production. No excess is observed compared to\nthe background prediction, and upper limits at the 95% confidence level are set\non the Phi[++] production cross section, under specific assumptions on its\nbranching fractions. Lower bounds on the Phi[++] mass are reported, providing\nsignificantly more stringent constraints than previously published limits.", "category": "hep-ex" }, { "text": "High Energy Colliding Beams; What Is Their Future?: The success of the first few years of LHC operations at CERN, and the\nexpectation of more to come as the LHC performance improves, are already\nleading to discussions of what should be next for both proton-proton and\nelectron-positron colliders. In this discussion I see too much theoretical\ndesperation caused by the so far unsuccessful hunt for what is beyond the\nStandard Model, and too little of the necessary interaction of the accelerator,\nexperimenter, and theory communities necessary for a scientific and engineering\nsuccess. Here, I give my impressions of the problem, its possible solution, and\nwhat is needed to have both a scientifically productive and financially viable\nfuture.", "category": "hep-ex" }, { "text": "An Improved Determination of $\u03b1_{S}$ From Neutrino-Nucleon\n Scattering: We present an improved determination of the proton structure functions\n$F_{2}$ and $xF_{3}$ from the CCFR $\\nu $-Fe deep inelastic scattering (DIS)\nexperiment. Comparisons to high-statistics charged-lepton scattering results\nfor $F_{2}$ from the NMC, E665, SLAC, and BCDMS experiments, after correcting\nfor quark-charge and heavy-target effects, indicate good agreement for $x>0.1$\nbut some discrepancy at lower x. The $Q^{2}$ evolution of the structure\nfunctions yields the quantum chromodynamics (QCD) scale parameter\n$\\Lambda_{\\bar{MS}}^{NLO,(4)}=337 \\pm 28$(exp.) MeV. This corresponds to a\nvalue of the strong coupling constant at the scale of mass of the Z-boson of\n$\\alpha _{S}(M_{Z}^{2})=0.119 \\pm 0.002 (exp.) \\pm 0.004 (theory)$ and is one\nof the most precise measurements of this quantity.", "category": "hep-ex" }, { "text": "Measurement of the ttbar production cross section using dilepton events\n in ppbar collisions: We present a measurement of the ttbar production cross section sigma(ttbar)\nin ppbar collisions at sqrt{s} = 1.96 TeV using 5.4 fb-1 of integrated\nluminosity collected with the D0 detector. We consider final states with at\nleast two jets and two leptons (ee, emu, mumu), and events with one jet for the\nthe emu final state as well. The measured cross section is sigma(ttbar)= 7.36\n+0.90-0.79 (stat + syst) pb. This result combined with the cross section\nmeasurement in the lepton + jets final state yields sigma(ttbar)=7.56\n+0.63-0.56 (stat + syst) pb, which agrees with the standard model expectation.\nThe relative precision of 8% of this measurement is comparable to the latest\ntheoretical calculations.", "category": "hep-ex" }, { "text": "Observation of a new \u03c7_b state at ATLAS and a new \u039e_b baryon at CMS: Two recent observations of new b hadrons in pp collisions at \\sqrt{s} = 7 TeV\nat the Large Hadron Collider (LHC) are presented. The ATLAS collaboration has\nobserved a new state in radiative transitions to \\Upsilon(1S) and \\Upsilon(2S)\nand interprets this as the first observation of the \\chi_b(3P) states. The CMS\ncollaboration has observed a new b baryon decaying to \\Xi_b-\\pi+ (plus charge\nconjugates). This is interpreted as a neutral J^P = 3/2^+ \\Xi_b* baryon.", "category": "hep-ex" }, { "text": "Charmed Hadrons from Fragmentation and B Decays: The fragmentation functions of $D^0$, $D^{\\pm}$, $D_s^{\\pm}$, $D^{*o}$,\n$D^{*\\pm}$ and $\\Lambda_c^{\\pm}$ at $\\sqrt{s}$$\\simeq$10.6 GeV are measured\nwith a data set of 102.7 fb$^{-1}$. Fragmentation model parametrizations\n(Peterson, Kartvelishvili, Collins-Spiller, Lund, and Bowler models) are\ncompared to the data. The data at high $x$$\\simeq$1 indicate a contribution of\nnon-perturbative QCD processes.", "category": "hep-ex" }, { "text": "Elliptic flow of charm and strange hadrons in high-multiplicity pPb\n collisions at $\\sqrt{s_{_\\mathrm{NN}}} =$ 8.16 TeV: The elliptic azimuthal anisotropy coefficient ($v_2$) is measured for charm\n(D$^0$) and strange (K$_\\mathrm{S}^0$, $\\Lambda$, $\\Xi^-$, and $\\Omega^-$)\nhadrons, using a data sample of pPb collisions collected by the CMS experiment,\nat a nucleon-nucleon center-of-mass energy $\\sqrt{s_{_\\mathrm{NN}}} =$ 8.16\nTeV. A significant positive $v_2$ signal from long-range azimuthal correlations\nis observed for all particle species in high-multiplicity pPb collisions. The\nmeasurement represents the first observation of possible long-range\ncollectivity for open heavy flavor hadrons in small systems. The results\nsuggest that charm quarks have a smaller $v_2$ than the lighter quarks,\nprobably reflecting a weaker collective behavior. This effect is not seen in\nthe larger PbPb collision system at $\\sqrt{s_{_\\mathrm{NN}}} =$ 5.02 TeV, also\npresented.", "category": "hep-ex" }, { "text": "Search for Extra Dimensions in the Diphoton Channel: We present a search for extra dimensions in the diphoton channel using the\nCMS detector at the Large Hadron Collider. The search is focused on the\nforthcoming 2009--2010 run at 10 TeV center$-$of$-$mass energy and $\\sim 100$\npb$^{-1}$ of data. We discuss event selection and optimization, as well as\ndata-driven methods of estimating various backgrounds and efficiencies. The\ndominant source of background after all the selection requirements is SM\ndiphoton production. We quote the sensitivity of the search both in terms of\nlimits on the parameters of large and warped extra dimensions in the case of no\nexcess observed, and in terms of signal discovery significance, if an excess is\nseen in data.", "category": "hep-ex" }, { "text": "Study of hard double-parton scattering in four-jet events in $pp$\n collisions at $\\sqrt{s} = 7$ TeV with the ATLAS experiment: Inclusive four-jet events produced in proton-proton collisions at a\ncentre-of-mass energy of $\\sqrt{s} = 7$ TeV are analysed for the presence of\nhard double-parton scattering using data corresponding to an integrated\nluminosity of 37.3 pb$^{-1}$, collected with the ATLAS detector at the LHC. The\ncontribution of hard double-parton scattering to the production of four-jet\nevents is extracted using an artificial neural network, assuming that hard\ndouble-parton scattering can be approximated by an uncorrelated overlaying of\ndijet events. For events containing at least four jets with transverse momentum\n$p_{\\mathrm{T}} \\geq 20$ GeV and pseudorapidity $\\eta \\leq 4.4$, and at least\none having $p_{\\mathrm{T}} \\geq 42.5$ GeV, the contribution of hard\ndouble-parton scattering is estimated to be $f_{\\mathrm{DPS}} = 0.092\n^{+0.005}_{-0.011} (\\mathrm{stat.}) ^{+0.033}_{-0.037} (\\mathrm{syst.})$. After\ncombining this measurement with those of the inclusive dijet and four-jet\ncross-sections in the appropriate phase space regions, the effective overlap\narea between the interacting protons, $\\sigma_{\\mathrm{eff}}$, was determined\nto be $\\sigma_{\\mathrm{eff}} = 14.9 ^{+1.2}_{-1.0} (\\mathrm{stat.})\n^{+5.1}_{-3.8} (\\mathrm{syst.})$ mb. This result is consistent within the\nquoted uncertainties with previous measurements of $\\sigma_{\\mathrm{eff}}$,\nperformed at centre-of-mass energies between 63 GeV and 8 TeV using various\nfinal states, and it corresponds to $21^{+7}_{-6}$% of the total inelastic\ncross-section measured at $\\sqrt{s} = 7$ TeV. The distributions of the\nobservables sensitive to the contribution of hard double-parton scattering,\ncorrected for detector effects, are also provided.", "category": "hep-ex" }, { "text": "Observation of a diffractive contribution to dijet production in\n proton-proton collisions at $\\sqrt{s} = 7$ TeV: The differential cross section measurement for dijet production at\nproton-proton collisions at $\\sqrt{s}=7$ TeV is presented as a function of an\napproximation for the fractional momentum loss of the scattered proton\n($\\tilde{\\xi}$), an useful observable to distinguish model predictions of\ndiffractive and nondiffractive components. The data was collected by the CMS\ndetector at low instantaneous luminosity runs at LHC, corresponding to an\nintegrated luminosity of $2.7 {\\rm nb}^{-1}$. This is the first observation of\nsingle diffractive dijets at LHC.", "category": "hep-ex" }, { "text": "The Physics of Deep-Inelastic Scattering at HERA: In this paper an introduction to the physics of deep-inelastic scattering is\ngiven together with an account of some of the most recent results on the proton\nstructure obtained in electron-- and positron--proton collisions at the HERA\ncollider.", "category": "hep-ex" }, { "text": "Measurements of Neutrino Cross Sections Near 1 GeV: We summarise recent neutrino and antineutrino measurements near 1 GeV by the\nK2K, MiniBooNE and SciBooNE collaborations. We focus on experimental methods\nand note discrepancies between the most commonly used models for\nneutrino-nucleus interactions and recent high statistics observations of\ncharged-current quasi-elastic scattering as well as charged and neutral current\npion production on carbon and oxygen. We discuss possible directions for future\nmeasurements.", "category": "hep-ex" }, { "text": "Some Properties of the Very High Q^2 Events of HERA: The kinematic reconstruction of neutral current high Q^2 events at HERA is\ndiscussed in detail using as an example the recently published events of the H1\nand ZEUS collaborations at Q^2 > 15000 GeV^2 and M > 180 GeV, which are more\nnumerous than expected from Standard Model predictions. Taking into account the\ncomplete information of these events, the mass reconstruction is improved and\nthe difference between the average mass of the samples of the two experiments\nis reduced from 26+/-10 GeV to 17+/-7 GeV, but remains different enough to\nrender unlikely an interpretation of the excess observed by the two\ncollaborations as originating from the decay of a single narrow resonance.", "category": "hep-ex" }, { "text": "Measurement of the neutrino mixing angle $\u03b8_{23}$ in NOvA: This Letter reports new results on muon neutrino disappearance from NOvA,\nusing a 14 kton detector equivalent exposure of $6.05\\times10^{20}$\nprotons-on-target from the NuMI beam at the Fermi National Accelerator\nLaboratory. The measurement probes the muon-tau symmetry hypothesis that\nrequires maximal mixing ($\\theta_{23} = \\pi/4$). Assuming the normal mass\nhierarchy, we find $\\Delta m^2 = (2.67 \\pm 0.11)\\times 10^{-3}$ eV$^2$ and\n$\\sin^2 \\theta_{23}$ at the two statistically degenerate values\n$0.404^{+0.030}_{-0.022}$ and $0.624^{+0.022}_{-0.030}$, both at the 68%\nconfidence level. Our data disfavor the maximal mixing scenario with 2.6\n$\\sigma$ significance.", "category": "hep-ex" }, { "text": "A search for resonant production of $t\\bar{t}$ pairs in $4.8\\\n \\rm{fb}^{-1}$ of integrated luminosity of $p\\bar{p}$ collisions at\n $\\sqrt{s}=1.96\\ \\rm{TeV}$: We search for resonant production of tt pairs in 4.8 fb^{-1} integrated\nluminosity of ppbar collision data at sqrt{s}=1.96 TeV in the lepton+jets decay\nchannel, where one top quark decays leptonically and the other hadronically. A\nmatrix element reconstruction technique is used; for each event a probability\ndensity function (pdf) of the ttbar candidate invariant mass is sampled. These\npdfs are used to construct a likelihood function, whereby the cross section for\nresonant ttbar production is estimated, given a hypothetical resonance mass and\nwidth. The data indicate no evidence of resonant production of ttbar pairs. A\nbenchmark model of leptophobic Z \\rightarrow ttbar is excluded with m_{Z'} <\n900 GeV at 95% confidence level.", "category": "hep-ex" }, { "text": "Results from the first heavy ion run at the LHC: Early November 2010, the LHC collided for the first time heavy ions, Pb on\nPb, at a centre-of-mass energy of 2.76 TeV/nucleon. This date marked both the\nend of almost 20 years of preparing for nuclear collisions at the LHC, as well\nas the start of a new era in ultra-relativistic heavy ion physics at energies\nexceeding previous machines by more than an order of magnitude. This\ncontribution summarizes some of the early results from all three experiments\nparticipating in the LHC heavy ion program (ALICE, ATLAS, and CMS), which show\nthat the high density matter created at the LHC, while much hotter and larger,\nstill behaves like the very strongly interacting, almost perfect liquid\ndiscovered at RHIC. Some surprising and even puzzling results are seen in\nparticle ratios, jet-quenching, and Quarkonia suppression observables. The\noverall experimental conditions at the LHC, together with its set of powerful\nand state-of-the-art detectors, should allow for precision measurements of\nquark-gluon-plasma parameters like viscosity and opacity.", "category": "hep-ex" }, { "text": "Measurement of $CP$ asymmetries in $B^0 \\rightarrow K^0_S K^0_S K^0_S$\n decays at Belle II: We report a measurement of decay-time dependent charge-parity ($CP$)\nasymmetries in $B^0 \\rightarrow K^0_S K^0_S K^0_S$ decays. We use $387 \\times\n10^6 B\\bar{B}$ pairs collected at the $\\Upsilon(4S)$ resonance with the Belle\nII detector at the SuperKEKB asymmetric-energy electron-positron collider. We\nreconstruct 220 signal events and extract the $CP$-violating parameters $S$ and\n$C$ from a fit to the distribution of the decay-time difference between the two\n$B$ mesons. The resulting confidence region is consistent with previous\nmeasurements in $B^0 \\rightarrow K^0_S K^0_S K^0_S$ and $B^0 \\rightarrow\n(c\\bar{c})K^0$ decays, and with predictions based on the standard model.", "category": "hep-ex" }, { "text": "A measurement of the WZ and ZZ production cross sections using leptonic\n final states in 8.6 fb$^{-1}$ of $p\\bar{p}$ collisions: We study the processes $p\\bar{p} \\rightarrow WZ \\rightarrow\n\\ell\\nu\\ell^+\\ell-$ and $p\\bar{p} \\rightarrow ZZ \\rightarrow\n\\ell^+\\ell^-\\nu\\bar{\\nu}, where $\\ell$ = $e$ or ${\\mu}$. Using 8.6 fb$^{-1} of\nintegrated luminosity collected by the D0 experiment at the Fermilab Tevatron\ncollider, we measure the $WZ$ production cross section to be\n4.50$^{+0.63}_{-0.66} pb which is consistent with, but slightly above a\nprediction of the standard model. The ZZ cross section is measured to be 1.64\n$\\pm$ 0.46 pb, in agreement with a prediction of the standard model.\nCombination with an earlier analysis of the $ZZ \\rightarrow\n\\ell^+\\ell^-\\ell^+\\ell^-$ channel yields a $ZZ$ cross section of\n1.44$^{+0.35}_{-0.34}$ pb.", "category": "hep-ex" }, { "text": "Exclusively produced rho^0 asymmetries on the deuteron and future GPD\n measurements at COMPASS: Generalized parton distributions (GPDs) provide a new and powerful framework\nfor a complete description of the nucleon structure. They can provide a\nthree-dimensional picture of how the quarks and gluons form a nucleon. GPDs can\nbe probed experimentally in hard exclusive meson production or deeply virtual\nCompton scattering (DVCS). The COMPASS experiment at CERN is a unique place to\nstudy these reactions. At COMPASS, a high energy polarized positive or negative\nmuon beam is scattered off a polarized or unpolarized fixed target. First\nresults for exclusive rho^0 meson production are shown. The transverse target\nspin asymmetry for exclusively produced rho^0 on a transversely polarized\ndeuteron target has been measured. Prospects for future measurements of DVCS\nand exclusive meson production at COMPASS will be shown. The experiment will\nuse the existing COMPASS spectrometer with a new target, a new recoil detector\nand extended calorimetry. Simulations for different models and a test of the\nrecoil detector have been performed.", "category": "hep-ex" }, { "text": "Tracking Performance of the HERA-B Outer Tracker PC Chambers: The paper was withdrawn by the authors since it has not been reviewed and\napproved by an official body within the collaboration.", "category": "hep-ex" }, { "text": "A realistic coalescence model for deuteron production: A microscopic understanding of (anti)deuteron production in hadron-hadron\ncollisions is the subject of many experimental and theoretical efforts in\nnuclear physics. This topic is also very relevant for astrophysics, since the\nrare production of antinuclei in our Universe could be a doorway to discover\nnew physics. In this work, we describe a new coalescence afterburner for event\ngenerators based on the Wigner function formalism and we apply it to the\n(anti)deuteron case, taking into account a realistic particle emitting source.\nThe model performance is validated using the EPOS and PYTHIA event generators\napplied to proton-proton collisions at the centre-of-mass energy $\\sqrt{s}=$ 13\nTeV, triggered for high multiplicity events, and the experimental data measured\nby ALICE in the same collision system. The model relies on the direct\nmeasurement of the particle emitting source carried out by means of\nnucleon-nucleon femtoscopic correlations in the same collision system and\nenergy. The resulting model is used to predict deuteron differential spectra\nassuming different deuteron wavefunctions within the Wigner function formalism.\nThe predicted deuteron spectra show a clear sensitivity to the choice of the\ndeuteron wavefunction. The Argonne $v_{18}$ wavefunction provides the best\ndescription of the experimental data. This model can now be used to study the\nproduction of (anti)deuterons over a wide range of collision energies and be\nextended to heavier nuclei.", "category": "hep-ex" }, { "text": "Heavy Flavors in High Energy ep Collisions: Most recent measurements of open charm and beauty production in high energy\nep collisions at HERA are reviewed. The measurements explored the different\naspects of quantum chromodynamics involved in the process of heavy flavor\nproduction. The results are compared with perturbative theoretical calculations\nat next-to-leading order.", "category": "hep-ex" }, { "text": "A potential sterile neutrino search utilizing spectral distortion in a\n two-reactor/one-detector configuration: There is an observed deficit of about 6\\% in the expected rate of\nanti-neutrino interactions when averaging over many different reactor\nexperiments. While the significance of the deficit is low (98.6 \\% CL), there\nis speculation that a non-interacting \"sterile\" neutrino could be the cause. In\nthis paper we explore the possibility of a two-reactor/one-detector experiment\nat intermediate distances (100-500 meters) to look for a sterile neutrino in\nthe mass range implied by this deficit. A method for probing $\\Delta m^2$ phase\nspace is developed using interference patterns between two oscillated spectra\nat different baselines. This method is used to investigate the potential\nsensitivity of the Double Chooz experiment, which has a single Near Detector at\ndistances of 351 m and 465 m from two reactors of identical design. We conclude\nthat Double Chooz could investigate sterile neutrino in the $\\Delta m^{2}$\nrange of 0.002 to 0.5 eV$^2$ over 5 years of near detector running.", "category": "hep-ex" }, { "text": "Higgs Discovery before LHC?: The proposed Run IIb of the Tevatron Collider will provide 15 fb-1 worth of\nppbar data at c.o.m energy of 2 TeV per experiment by year 2007. We review the\nplans of the Tevatron accelerator complex upgrade and the plans for the\nupgrades of the experiments to match this challenge. Perspectives for the\ndiscovery of an Higgs particle are reviewed and the concrete possibility of a 5\nsigmas discovery for a low mass Higgs are discussed.", "category": "hep-ex" }, { "text": "Measurement of the pi^0 -> e^+e^-gamma Dalitz decay at the Mainz\n Microtron: The Dalitz decay pi^0 -> e^+e^-gamma has been measured in the gamma p -> pi^0\np reaction with the A2 tagged-photon facility at the Mainz Microtron, MAMI. The\nvalue obtained for the slope parameter of the pi^0 electromagnetic transition\nform factor, a_pi = 0.030+/-0.010_tot, is in agreement with existing\nmeasurements of this decay and with recent theoretical calculations. The\nuncertainty obtained in the value of a_pi is lower than in previous results\nbased on the pi^0 -> e^+e^-gamma decay.", "category": "hep-ex" }, { "text": "Physics reach of a low threshold scintillating argon bubble chamber in\n coherent elastic neutrino-nucleus scattering reactor experiments: The physics reach of a low threshold (100 eV) scintillating argon bubble\nchamber sensitive to Coherent Elastic neutrino-Nucleus Scattering (CE$\\nu$NS)\nfrom reactor neutrinos is studied. The sensitivity to the weak mixing angle,\nneutrino magnetic moment, and a light $Z'$ gauge boson mediator are analyzed. A\nMonte Carlo simulation of the backgrounds is performed to assess their\ncontribution to the signal. The analysis shows that world-leading sensitivities\nare achieved with a one-year exposure for a 10 kg chamber at 3 m from a 1\nMW$_{th}$ research reactor or a 100 kg chamber at 30 m from a 2000 MW$_{th}$\npower reactor. Such a detector has the potential to become the leading\ntechnology to study CE$\\nu$NS using nuclear reactors.", "category": "hep-ex" }, { "text": "Probing gluon spin-momentum correlations in transversely polarized\n protons through midrapidity isolated direct photons in $p^\\uparrow+p$\n collisions at $\\sqrt{s}=200$ GeV: Studying spin-momentum correlations in hadronic collisions offers a glimpse\ninto a three-dimensional picture of proton structure. The transverse\nsingle-spin asymmetry for midrapidity isolated direct photons in $p^\\uparrow+p$\ncollisions at $\\sqrt{s}=200$ GeV is measured with the PHENIX detector at the\nRelativistic Heavy Ion Collider (RHIC). Because direct photons in particular\nare produced from the hard scattering and do not interact via the strong force,\nthis measurement is a clean probe of initial-state spin-momentum correlations\ninside the proton and is in particular sensitive to gluon interference effects\nwithin the proton. This is the first time direct photons have been used as a\nprobe of spin-momentum correlations at RHIC. The uncertainties on the results\nare a fifty-fold improvement with respect to those of the one prior measurement\nfor the same observable, from the Fermilab E704 experiment. These results\nconstrain gluon spin-momentum correlations in transversely polarized protons.", "category": "hep-ex" }, { "text": "Recent results on the helicity structure of the nucleon from HERMES: The HERMES experiment has measured double spin asymmetries of inclusive and\nsemi-inclusive cross sections for the production of charged hadrons in\ndeep-inelastic scattering of polarised positrons on polarised hydrogen and\ndeuterium targets, in the kinematic range 0.023 < x < 0.6, and 1 GeV^2 < Q^2 <\n15 GeV^2. For the data taken on the deuterium target, a RICH detector provides\nthe complete identification of charged pions and kaons. From the inclusive\nmeasurements on deuterium, the polarised structure function g_1^d has been\nextracted with high precision. Together with the semi-inclusive measurements,\nquark polarisations are extracted separately for the u, ubar, d, dbar, and (s +\nsbar) flavours in a LO QCD analysis. Furthermore, a possible breaking of\nflavour symmetry in the polarised light sea, (Delta ubar - Delta dbar), was\nmeasured for the first time and found to be consistent with zero within the\nexperimental precision.", "category": "hep-ex" }, { "text": "A Data-Driven Method of Background Prediction at NOvA: NOvA is a long-baseline neutrino oscillation experiment that will use the\nNuMI beam originating at Fermilab. NOvA enables the study of two oscillation\nchannels: $\\nu_{\\mu}$ disappearance and $\\nu_{e}$ appearance. It consists of\ntwo functionally identical detectors, the near detector (ND) at Fermilab and\nthe far detector (FD) near International Falls in Northern Minnesota. The ND\nwill be used to study the neutrino beam spectrum and composition before\noscillation, and measure background rate to the $\\nu_e$ appearance search. In\nthis paper, I describe a data-driven technique to estimate the neutral current\n(NC) component of the ND spectrum. Using the $\\nu_{\\mu}$ CC interactions where\nthe reconstructed muon is removed from the event, we produce a well understood\nsample of hadronic showers that resemble NC interactions.", "category": "hep-ex" }, { "text": "Energy dependence of the charged multiplicity in deep inelastic\n scattering at HERA: The charged multiplicity distributions and the mean charged multiplicity have\nbeen investigated in inclusive neutral current deep inelastic $ep$ scattering\nwith the ZEUS detector at HERA, using an integrated luminosity of 38.6\npb$^{-1}$. The measurements were performed in the current region of the Breit\nframe, as well as in the current fragmentation region of the hadronic\ncentre-of-mass frame. The KNO-scaling properties of the data were investigated\nand the energy dependence was studied using different energy scales. The data\nare compared to results obtained in $\\epem$ collisions and to previous DIS\nmeasurements as well as to leading-logarithm parton-shower Monte Carlo\npredictions.", "category": "hep-ex" }, { "text": "Dalitz Plot Analysis of D_s+ -> pi+ pi- pi+: A Dalitz plot analysis of approximately 13,000 Ds+ decays to pi+pi-pi+ has\nbeen performed. The analysis uses a 384 fb-1 data sample recorded by the BaBar\ndetector at the PEP-II asymmetric-energy e+e- storage ring running at center of\nmass energies near 10.6 GeV. Amplitudes and phases of the intermediate\nresonances which contribute to this final state are measured. A high precision\nmeasurement of the ratio of branching fractions is performed: BR(Ds+ ->\npi+pi-pi+)/BR(Ds+ -> K+ K- pi+)=0.199 +/- 0.004 +/- 0.009. Using a\nmodel-independent partial wave analysis, the amplitude and phase of the S-wave\nhave been measured.", "category": "hep-ex" }, { "text": "Measurement of ${C\\!P}$ violation parameters and polarisation fractions\n in ${B_s^0\\to J/\u03c8\\overline{K}^{*0}}$ decays: The first measurement of ${C\\!P}$ asymmetries in the decay ${B_s^0\\to J/\\psi\n\\overline{K}^{*}(892)^{0}}$ and an updated measurement of its branching\nfraction and polarisation fractions are presented. The results are obtained\nusing data corresponding to an integrated luminosity of $3.0\\,fb^{-1}$ of\nproton-proton collisions recorded with the LHCb detector at centre-of-mass\nenergies of $7$ and $8\\,\\mathrm{TeV}$. Together with constraints from ${B^0\\to\nJ/\\psi \\rho^0}$, the results are used to constrain additional contributions due\nto penguin diagrams in the ${C\\!P}$-violating phase ${{\\phi}_{s}}$, measured\nthrough ${B_s^0}$ decays to charmonium.", "category": "hep-ex" }, { "text": "Search for the Standard Model Higgs Boson in the Lepton + Missing\n Transverse Energy + Jets Final State in ATLAS: A search for the Standard Model Higgs boson has been performed in the H\n\\rightarrow WW \\rightarrow l{\\nu}jj channel in 1.04 fb-1 of pp collisions at\n\\surds = 7 TeV collected with the ATLAS detector at the Large Hadron Collider.\nNo significant excess of events is observed over the expected background and\nlimits on the Higgs boson production cross section are derived for a Higgs\nboson mass in the range 240 GeV < mH < 600 GeV. The best sensitivity is reached\nfor mH = 400 GeV, where the 95% confidence level upper bound on the\ncross-section for Higgs boson production times the branching ratio for H\n\\rightarrow W W is 3.1 pb, or 2.7 times the Standard Model prediction.", "category": "hep-ex" }, { "text": "First Measurement of the Double Spin Asymmetry in $\\vec{e}\\vec{p}\\to e'\n \u03c0^+ n$ in the Resonance Region: The double spin asymmetry in the $\\vec{e}\\vec{p}\\to e' \\pi^+ n$ reaction has\nbeen measured for the first time in the resonance region for four-momentum\ntransfer $Q^2=0.35-1.5$ GeV$^2$. Data were taken at Jefferson Lab with the CLAS\ndetector using a 2.6 GeV polarized electron beam incident on a polarized solid\nNH$_3$ target. Comparison with predictions of phenomenological models shows\nstrong sensitivity to resonance contributions. Helicity-1/2 transitions are\nfound to be dominant in the second and third resonance regions. The measured\nasymmetry is consistent with a faster rise with $Q^2$ of the helicity asymmetry\n$A_1$ for the $F_{15}(1680)$ resonance than expected from the analysis of the\nunpolarized data.", "category": "hep-ex" }, { "text": "Measurement of the p\\bar{p}\\to WZ + X cross section at \\sqrt{s}=1.96 TeV\n and limits on WWZ trilinear gauge couplings: We present measurements of the process $p\\bar{p} \\to WZ+X \\to \\ell^{\\prime}\n\\nu_{\\ell^{\\prime}} \\ell \\bar{\\ell}$ at $\\sqrt{s}=1.96$ TeV, where $\\ell$ and\n$\\ell^{\\prime}$ are electrons or muons. Using 1 fb$^{-1}$ of data from the D0\nexperiment, we observe 13 candidates with an expected background of $4.5\\pm0.6$\nevents and measure a cross section $\\sigma(WZ)=2.7^{+1.7}_{-1.3}$ pb. From the\nnumber of observed events and the $Z$ boson transverse momentum distribution,\nwe limit the trilinear $WWZ$ gauge couplings to $-0.17 \\le \\lambda_Z \\le 0.21$\n$(\\Delta \\kappa_Z = 0)$ at the 95% C.L. for a form factor scale $\\Lambda=2$\nTeV. Further, assuming that $\\Delta g^Z_1 = \\Delta\\kappa_Z$, we find $-0.12 \\le\n\\Delta\\kappa_Z \\le 0.29$ $(\\lambda_Z=0)$ at the 95% C.L. These are the most\nrestrictive limits on the $WWZ$ couplings available to date.", "category": "hep-ex" }, { "text": "Transverse-longitudinal HBT correlations in proton-antiproton collisions\n at root(s) = 630 GeV: Correlations of like-sign pion pairs emerging from proton-antiproton\ncollisions are analysed in the two-dimensional (q_L,q_T) decomposition of the\nthree-momentum difference q. While the data cannot be adequately represented by\ngaussian, exponential, power-law or Edgeworth parametrisations, more elaborate\nones such as Levy and an exponential with a cross term do better. A two-scale\nmodel using a hard cut to separate small and large scales may indicate a core\nthat is more prolate than the halo. Consideration not only of the interference\npeak at small (q_L,q_T), but also of the shape of the correlation distribution\nat intermediate momentum differences is crucial to understanding the data.", "category": "hep-ex" }, { "text": "Study of tau-neutrino production at the CERN SPS: The DsTau project proposes to study tau-neutrino production in high-energy\nproton interactions. The outcome of this experiment are prerequisite for\nmeasuring the $\\nu_\\tau$ charged-current cross section that has never been well\nmeasured. Precisely measuring the cross section would enable testing of lepton\nuniversality in $\\nu_\\tau$ scattering and it also has practical implications\nfor neutrino oscillation experiments and high-energy astrophysical $\\nu_\\tau$\nobservations. $D_s$ mesons, the source of tau neutrinos, following high-energy\nproton interactions will be studied by a novel approach to detect the\ndouble-kink topology of the decays $D_s \\rightarrow \\tau\\nu_\\tau$ and\n$\\tau\\rightarrow\\nu_\\tau X$. Directly measuring $D_s\\rightarrow \\tau$ decays\nwill provide an inclusive measurement of the $D_s$ production rate and decay\nbranching ratio to $\\tau$. The momentum reconstruction of $D_s$ will be\nperformed by combining topological variables. This project aims to detect 1,000\n$D_s \\rightarrow \\tau$ decays in $2.3 \\times 10^8$ proton interactions in\ntungsten target to study the differential production cross section of $D_s$\nmesons. To achieve this, state-of-the-art emulsion detectors with a\nnanometric-precision readout will be used. The data generated by this project\nwill enable the $\\nu_\\tau$ cross section from DONUT to be re-evaluated, and\nthis should significantly reduce the total systematic uncertainty. Furthermore,\nthese results will provide essential data for future $\\nu_\\tau$ experiments\nsuch as the $\\nu_\\tau$ program in the SHiP project at CERN. In addition, the\nanalysis of $2.3 \\times 10^8$ proton interactions, combined with the expected\nhigh yield of $10^5$ charmed decays as by-products, will enable the extraction\nof additional physical quantities.", "category": "hep-ex" }, { "text": "Search for Charmonium States Decaying to J/psi gamma gamma Using\n Initial-State Radiation Events: We study the processes e+e- -> (J/psi gamma gamma) gamma and e+e- -> (J/psi\npi- pi+) gamma where the hard photon radiated from an initial e+e- collision\nwith center-of-mass (CM) energy near 10.58 GeV is detected. In the final state\nJ/psi gamma gamma we consider J/psi pi0, J/psi eta, chi_{c1} gamma, and\nchi_{c2} gamma candidates. The invariant mass of the hadronic final state\ndefines the effective e+e- CM energy in each event, so these data can be\ncompared with direct e+e- measurements. We report 90% CL upper limits for the\nintegrated cross section times branching fractions of the J/psi gamma gamma\nchannels in the Y(4260) mass region.", "category": "hep-ex" }, { "text": "Hadronization mechanisms (via heavy-flavour hadrons): Experiment: The formation of hadrons is a fundamental process in nature that can be\ninvestigated at particle colliders. Given their large mass, heavy quarks (charm\nand beauty) are produced only in initial hard-scatterings, prior to\nhadronisation, which determines instead the relative abundances and the\nkinematics of the various heavy-flavour hadron species. As several recent\nfindings demonstrate, with \\ee collisions as a \"vacuum-like\" reference at one\nextreme, and central AA as a dense, extended-size system characterised by flow\nand local equilibrium at the opposite extreme, different collision systems\noffer a lever arm that can be exploited to probe with a range of heavy-flavour\nhadron species the onset of various hadronisation processes. In these\nproceedings, a selection of the experimental results related to heavy-flavour\nhadronisation shown for the first time at the Hard Probes 2023 conference is\npresented together with some of the most important ones of the last years. The\nfocus is on open-heavy flavour measurements. The comparison with model\npredictions and connections among the results in \\ee, proton--proton,\nproton--nucleus, nucleus--nucleus collisions are discussed.", "category": "hep-ex" }, { "text": "Measurement of $ D^{*\\pm}$ production in deep inelastic scattering at\n HERA: The production of $D^{*\\pm}$ mesons in deep inelastic $ep$ scattering has\nbeen measured for exchanged photon virtualities $ 5 eta h Decays: We report measurements of $B$ to pseudoscalar-pseudoscalar decays with at\nleast one eta meson in the final state using 140 fb^{-1} of data collected by\nthe Belle detector at KEKB e^+ e^- collider. We observe the decays of B^+-> eta\npi^+ and B^+-> eta K^+; the measured branching fractions are Br(B^+-> eta pi^+)\n= (4.8^{+0.8}_{-0.7}(stat) +- 0.3 (sys)) * 10^-6 and Br(B^+-> eta K^+) = (2.1\n+- 0.6 (stat) +- 0.2 (sys)) * 10^-6. Their corresponding CP violating\nasymmetries are measured to be 0.07 +- 0.15 +- 0.03 for eta pi^+- and -0.49 +-\n0.31 +- 0.07 for eta K^+-. No significant signals are found for neutral B meson\ndecays. We report the following upper limits on branching fractions at the 90%\nconfidence level: Br(B^0 -> eta K^0) < 2.0 * 10^-6, Br(B^0-> eta pi^0) < 2.5 *\n10^-6 and Br(B^0 -> eta eta) < 2.0 * 10^-6.", "category": "hep-ex" }, { "text": "Working with Arrays of Inexpensive EIDE Disk Drives: In today's marketplace, the cost per Terabyte of disks with EIDE interfaces\nis about a third that of disks with SCSI. Hence, three times as many particle\nphysics events could be put online with EIDE. The modern EIDE interface\nincludes many of the performance features that appeared earlier in SCSI. EIDE\nbus speeds approach 33 Megabytes/s and need only be shared between two disks\nrather than seven disks. The internal I/O rate of very fast (and expensive)\nSCSI disks is only 50 per cent greater than EIDE disks. Hence, two EIDE disks\nwhose combined cost is much less than one very fast SCSI disk can actually give\nmore data throughput due to the advantage of multiple spindles and head\nactuators. We explore the use of 12 and 16 Gigabyte EIDE disks with motherboard\nand PCI bus card interfaces on a number of operating systems and CPUs. These\ninclude Red Hat Linux and Windows 95/98 on a Pentium, MacOS and Apple's\nRhapsody/NeXT/UNIX on a PowerPC, and Sun Solaris on a UltraSparc 10\nworkstation.", "category": "hep-ex" }, { "text": "A measurement of CP-violation parameters in B0B0bar mixing using\n partially reconstructed D*- l+ nu_l events at BaBar: CP violation in B0B0bar mixing is characterized by the value of the parameter\n|q/p| being different from 1, and the Standard Model predicts this difference\nto be smaller than 10^{-3}. We present a measurement of this parameter using a\npartial reconstruction of one of the B mesons in the semileptonic channel D*-\nl+ nu_l, where only the hard lepton and the soft pion from the D*- --> D0bar\npi- decay are reconstructed. The flavor of the other B is determined by means\nof lepton tagging. The determination of |q/p| is then performed with a fit to\nthe proper time difference of the two B decays. We use a luminosity of 200.8\nfb^-1, collected at the Y(4S) resonance by the BaBar detector at the PEP-II\nasymmetrical-energy e+e- collider, in the period 1999-2004. We obtain the\npreliminary result:\n |q/p| - 1 = (6.5 +/- 3.4(stat.) +/- 2.0(syst.)) x 10^{-3}", "category": "hep-ex" }, { "text": "Measurement of the Ionization Yield of Neutron-Induced Proton Recoils in\n Tetramethylsilane: We report on a low energy measurement of the ionization yield in a\nTetramethylsilane Time Projection Chamber (TPC) using 2.8 MeV neutrons from a\ndeuterium-deuterium neutron generator. The proton recoil charge yield is\nmeasured at four different electric fields, finding a dependence that is well\ndescribed by the Thomas-Imel model. By comparing the proton recoil yield to\nthat obtained from $\\gamma$-ray calibrations, a quenching factor is obtained\nfor each electric field. These results demonstrate the feasibility of using\nroom temperature organic ionisation detectors to detect MeV-scale neutrons in\nthe proton-recoil channel.", "category": "hep-ex" }, { "text": "Measurement of the UT angle phi_2: We give a status report on measurements of the angle phi_2 (alpha) of the CKM\nunitarity triangle (UT) and the so-called Kpi puzzle. Results presented are\nmostly from the two B-factory experiments, Belle and BaBar.", "category": "hep-ex" }, { "text": "Model Independent Searches for New Physics at the Fermilab Tevatron\n Collider: The standard model is a successful but limited theory. There is significant\ntheoretical motivation to believe that new physics may appear at the energy\nscale of a few TeV, the lower end of which is currently probed by the Fermilab\nTevatron Collider. The methods used to search for physics beyond the standard\nmodel in a model independent way and the results of these searches based on 1.0\nfb-1 of data collected with the D0 detector and 2.0 fb^-1 at the CDF detector\nare presented.", "category": "hep-ex" }, { "text": "Is there new physics in the 1999 ALEPH data ?: The first results on searches performed by ALEPH on the 1999 data sample are\npresented here. They are based on an integrated luminosity of about 54 pb$^-1$\ncollected at the two centre-of-mass energies of 192 and 196 GeV. Preliminary\nresults on searches for supersymmetric particles and for the neutral Higgs\nbosons are shown.", "category": "hep-ex" }, { "text": "Prospects for discovering new gauge bosons, extra dimensions and contact\n interaction at the LHC: This talk is a review of possible discoveries of exotic not Standard Model\nPhysics in the early stage of LHC (first two years), with the ATLAS and CMS\nexperiments. LHC will be the first experiment ever to explore the TeV region\nand new exotic particles could be discovered at early stages of the LHC running\nif their masses are not too large. This talk is focused on three main search\ntopics: new vector bosons, contact interaction and extra dimensions.", "category": "hep-ex" }, { "text": "Top Quark Modelling and Tuning at CMS: Recent measurements dedicated to improving the understanding of modelling top\nquark pair (${\\text{t}\\overline{\\text{t}}}$) production at the LHC are\nsummarised. These measurements, performed with proton-proton collision data\ncollected by the CMS detector at $\\sqrt{s}=$ 13 TeV, probe the underlying event\nin ${\\text{t}\\overline{\\text{t}}}$ events, and use the abundance of jets in\n${\\text{t}\\overline{\\text{t}}}$ events to study the substructure of jets. A new\nset of tunes for PYTHIA 8, and their performance with\n${\\text{t}\\overline{\\text{t}}}$ data, are also discussed.", "category": "hep-ex" }, { "text": "Virtual Photon Structure at HERA: Measurements of the structure of the virtual photon in the transition region\nbetween quasi-real photons and those far from mass-shell have been made with\nthe ZEUS detector at HERA, using an integrated luminosity of 38pb-1. Dijet\nfinal states are identified, and differential cross sections are presented in\nterms of xgo, an estimator of the fraction of the photon energy which takes\npart in the QCD subprocess. Comparison is made to theoretical predictions.", "category": "hep-ex" }, { "text": "A New Generation of Neutrino Cross Section Experiments: Challenges and\n Opportunities: Our knowledge of neutrino cross sections at the GeV scale, instrumental to\ntest CP symmetry violation in the leptonic sector, has grown substantially in\nthe last two decades. Still, their precision and understanding are far from the\nstandard needed in contemporary neutrino physics. Nowadays, the knowledge of\nthe neutrino cross-section at $O(10\\%)$ causes the main systematic uncertainty\nin oscillation experiments and jeopardizes their physics reach. In this paper,\nwe envision the opportunities for a new generation of cross section experiments\nto be run in parallel with DUNE and HyperKamiokande. We identify the most\nprominent physics goals by looking at the theory and experimental limitations\nof the previous generation of experiments. We highlight the priorities in the\ntheoretical understanding of GeV cross-sections and the experimental challenges\nof this new generation of facilities.", "category": "hep-ex" }, { "text": "Proton Structure: Recent inclusive neutral current and charged current DIS data from\n HERA are discussed in context of pQCD and parton density functions.", "category": "hep-ex" }, { "text": "Charged Current Quasi-Elastic Interactions at MiniBooNE Confront Cross\n Section Monte Carlos: Neutrino oscillations have been established in solar and atmospheric\nneutrinos, but a third signal from the LSND experiment is incompatible with\nthree Standard Model neutrinos. The MiniBooNE experiment can confirm or refute\nthe LSND signal with 1E21 protons on target. While working towards the\noscillation result, MiniBooNE will accumulate more than 1E6 neutrino\ninteractions in the 0 to 2 GeV range which will greatly increase the world's\nknowledge of neutrino cross sections in this energy regime. Preliminary results\non the MiniBooNE muon neutrino charged current quasi-elastic analysis are\npresented and compared to the NUANCE, NEUT, and NEUGEN cross section Monte\nCarlos.", "category": "hep-ex" }, { "text": "Updated measurement of decay-time-dependent CP asymmetries in $D^0 \\to\n K^+K^-$ and $D^0 \\to \u03c0^+\u03c0^-$ decays: A search for decay-time-dependent charge-parity ($CP$) asymmetry in $D^0 \\to\nK^+K^-$ and $D^0 \\to \\pi^+\\pi^-$ decays is performed at the LHCb experiment\nusing proton-proton collision data recorded at a center-of-mass energy of\n13TeV, and corresponding to an integrated luminosity of 5.4fb$^{-1}$. The $D^0$\nmesons are required to originate from semileptonic decays of $b$ hadrons, such\nthat the charge of the muon identifies the flavor of the neutral $D$ meson at\nproduction. The asymmetries in the effective decay widths of $D^0$ and\n$\\overline{D}^0$ mesons are determined to be $A_{\\Gamma}(K^+K^-) = ( -4.3 \\pm\n3.6 \\pm 0.5 )\\times 10^{-4}$ and $A_{\\Gamma}(\\pi^+\\pi^-) = ( 2.2 \\pm 7.0 \\pm\n0.8)\\times 10^{-4}$, where the uncertainties are statistical and systematic,\nrespectively. The results are consistent with $CP$ symmetry and, when combined\nwith previous LHCb results, yield $A_{\\Gamma}(K^+K^-) = ( -4.4 \\pm 2.3 \\pm 0.6\n)\\times 10^{-4}$ and $A_{\\Gamma}(\\pi^+\\pi^-) = ( 2.5 \\pm 4.3 \\pm 0.7)\\times\n10^{-4}$.", "category": "hep-ex" }, { "text": "Observation of B->etarho+ and search for B0 Decays to eta'eta, etapi0,\n eta'pi0, and omegapi0: We present measurements of branching fractions for five B-meson decays to\ntwo-body charmless final states. The data, collected with the BABAR detector at\nthe Stanford Linear Accelerator Center, represent 459 million BBbar pairs. The\nresults for branching fractions are, in units of 10^{-6} (upper limits at 90%\nC.L.): BR(B+ -> etarho+) = 9.9 +/- 1.2 +/- 0.8, BR(B0 -> eta'eta) = 0.5 +/- 0.4\n+/- 0.1 (<1.2), BR(B0 -> etapi0) = 0.9 +/- 0.4 +/- 0.1 (<1.5), BR(B0 ->\neta'pi0) = 0.9 +/- 0.4 +/- 0.1 (<1.5), and BR(B0 -> omegapi0) = 0.07 +/- 0.26\n+/- 0.02 (<0.5). The first error quoted is statistical and the second\nsystematic. For the etarho+ mode, we measure the charge asymmetry Ach(B+ ->\netarho+) = 0.13 +/- 0.11 +/- 0.02.", "category": "hep-ex" }, { "text": "Capabilities of an Underwater Detector as a Neutrino Telescope and for\n the Neutrino Oscillation Search: We report on the results of a Monte Carlo simulation study of a km^3 scale\ndeep underwater Cherenkov detector aimed at detecting neutrinos of\nastrophysical origin. This analysis has been undertaken as part of the NEMO R&D\nproject to develop such an experiment close to the Southern Italian coasts. We\nhave studied the reconstruction capabilities of various arrays of phototubes in\norder to determine the detector geometries which optimize performance and cost.\nWe have also investigated the possibility of designing a detector with\ncharacteristics suited to an experiment on atmospheric neutrino oscillations.", "category": "hep-ex" }, { "text": "End-to-end particle and event identification at the Large Hadron\n Collider with CMS Open Data: From particle identification to the discovery of the Higgs boson, deep\nlearning algorithms have become an increasingly important tool for data\nanalysis at the Large Hadron Collider (LHC). We present an innovative\nend-to-end deep learning approach for jet identification at the Compact Muon\nSolenoid (CMS) experiment at the LHC. The method combines deep neural networks\nwith low-level detector information, such as calorimeter energy deposits and\ntracking information, to build a discriminator to identify different particle\nspecies. Using two physics examples as references: electron vs. photon\ndiscrimination and quark vs. gluon discrimination, we demonstrate the\nperformance of the end-to-end approach on simulated events with full detector\ngeometry as available in the CMS Open Data. We also offer insights into the\nimportance of the information extracted from various sub-detectors and describe\nhow end-to-end techniques can be extended to event-level classification using\ninformation from the whole CMS detector.", "category": "hep-ex" }, { "text": "Jet properties and correlations in multi-jet topologies in CMS: We present measurements of multi-jet event properties, performed using\nproton-proton collisions data recorded by the CMS experiment. The jet charge\nand jet mass distributions are considered in addition to a measurement of the\nazimuthal angular correlations in 2- and 3-jet events. The measurements are\ncompared to predictions including higher orders matched to parton shower and\nhadronization, together with predictions from semi-analytical calculations\nbeyond next-to-leading logarithmic accuracy.", "category": "hep-ex" }, { "text": "Search for direct chargino production in anomaly-mediated supersymmetry\n breaking models based on a disappearing-track signature in pp collisions at\n sqrt(s)=7 TeV with the ATLAS detector: A search for direct chargino production in anomaly-mediated supersymmetry\nbreaking scenarios is performed in pp collisions at sqrt(s) = 7 TeV using 4.7\nfb^-1 of data collected with the ATLAS experiment at the LHC. In these models,\nthe lightest chargino is predicted to have a lifetime long enough to be\ndetected in the tracking detectors of collider experiments. This analysis\nexplores such models by searching for chargino decays that result in tracks\nwith few associated hits in the outer region of the tracking system. The\ntransverse-momentum spectrum of candidate tracks is found to be consistent with\nthe expectation from the Standard Model background processes and constraints on\nchargino properties are obtained.", "category": "hep-ex" }, { "text": "First Results from the TOTEM Experiment: The first physics results from the TOTEM experiment are here reported,\nconcerning the measurements of the total, differential elastic, elastic and\ninelastic pp cross-section at the LHC energy of $\\sqrt{s}$ = 7 TeV, obtained\nusing the luminosity measurement from CMS. A preliminary measurement of the\nforward charged particle $\\eta$ distribution is also shown.", "category": "hep-ex" }, { "text": "Searches for Heavy Neutrinos at the CERN SPS: Searches for heavy neutrinos can be successfully performed by fixed target\nexperiments at the CERN SPS. New results obtained by the NA62 and NA48/2 kaon\nexperiments are summarized in this paper. The physics potential of future\nprojects exploiting SPS protons with beam dump facilities to enlarge the\nsensitivity to heavy neutrinos above the kaon mass limit are also outlined.", "category": "hep-ex" }, { "text": "Minimum Bias Measurements with ALICE at the LHC: ALICE (A Large Ion Collider Experiment) is one of the seven experiments at\nthe the Large Hadron Collider (LHC) at CERN, Geneva, Switzerland. ALICE is\nespecially designed for heavy-ion collisions but it also operates a rich\nproton-proton (pp) program. ALICE has collected pp collision data at\n$\\sqrt{s}=$ 0.9, 2.36, 2.76, and 7 TeV and lead-lead (Pb--Pb) collision data at\n$\\sqrt{s_{\\mathrm{NN}}}=$2.76 TeV. Here, we report minimum bias measurements\nobtained until the end of 2010: the results include measurements of\ncharged-particle pseudorapidity, multiplicity and transverse momentum\ndistributions. Also, the two-pion Bose-Einstein correlation and the measurement\nof antiproton-to-proton ratio will be discussed. Furthermore, results on the\nproduction of identified particles including strange particles will be shown as\nwell as first results from the first Pb--Pb run at the LHC.", "category": "hep-ex" }, { "text": "Bose-Einstein Correlations and the Tau-Model: Bose-Einstein correlations of pairs of identical charged pions produced in\nhadronic Z decays are analyzed in terms of various parametrizations. A good\ndescription is achieved using a L\\'evy stable distribution in conjunction with\na model where a particle's momentum is highly correlated with its space-time\npoint of production, the tau model. However, a small but significant elongation\nof the particle emission region is observed in the Longitudinal Center of Mass\nframe, which is not accommodated in the tau model. This is investigated using\nan ad hoc modification of the tau model.", "category": "hep-ex" }, { "text": "Search for Anomalous Production of Diphoton Events with Missing\n Transverse Energy at CDF and Limits on Gauge-Mediated Supersymmetry-Breaking\n Models: We present the results of a search for anomalous production of diphoton\nevents with large missing transverse energy using the Collider Detector at\nFermilab. In 202 $\\invpb$ of $\\ppbar$ collisions at $\\sqrt{s}=1.96$ TeV we\nobserve no candidate events, with an expected standard model background of\n$0.27\\pm0.07({\\rm stat})\\pm0.10({\\rm syst})$ events. The results exclude a\nlightest chargino of mass less than 167 GeV/$c^2$, and lightest neutralino of\nmass less than 93 GeV/$c^2$ at 95% C.L. in a gauge--mediated supersymmetry--\nbreaking model with a light gravitino.", "category": "hep-ex" }, { "text": "Heavy-flavour and quarkonia in heavy-ion collisions: The comparison of heavy-flavour hadron production in proton-proton, proton-Pb\nand Pb-Pb collisions at the LHC offers the opportunity to investigate the\nproperties of the high-density colour-deconfined state of strongly-interacting\nmatter (Quark Gluon Plasma, QGP) that is expected to be formed in high-energy\ncollisions of heavy nuclei. A review of the main quarkonium and open\nheavy-flavour results obtained by the ALICE, ATLAS and CMS experiments is\npresented.", "category": "hep-ex" }, { "text": "Status and prospects for the LHCb upgrade: High-precision measurements performed by the LHCb collaboration have opened a\nnew era in charm physics. Several crucial measurements, particularly in\nspectroscopy, rare decays and CP violation, can benefit from the increased\nstatistical power of an upgraded LHCb detector. The upgrade of LHCb detector,\nits software infrastructure, and the impact on charm physics are discussed in\ndetail.", "category": "hep-ex" }, { "text": "A novel current mode operating beam counter based on not preamplified\n HPDs: A novel system to monitor the intensity and the stability of a bunched beam\nof $\\simeq 1.2\\times 10^{7}$ antiprotons ($\\bar{p}$s) with a length of $\\simeq$\n250 ns (FWHM) and to measure its trapping efficiency in a Penning trap is\ndescribed. This system operates parasitically detecting the pions from the\nannihilation of part of the beam in a degrader. Six plastic scintillators have\nbeen coupled from one side to six proximity focused HPDs without preamplifiers\nand operating in current mode. This device works in the stray field of the\nATHENA magnet with no loss of efficiency; the gain can be varied from zero to a\nfew thousands with a precision better than 0.1% and the dynamic range is larger\nthan 8 orders of magnitude. Linearity and stability have been measured up to\ncharge responses of 100 nC, corresponding to the beam completely dumped. The\nbeam counter has been calibrated in two different and independent ways giving\nconsistent results.", "category": "hep-ex" }, { "text": "Search for New Physics Using High Mass Tau Pairs from 1.96-TeV\n Proton-Antiproton Collisions: We present the results of a search for anomalous resonant production of tau\nlepton pairs with large invariant mass, the first such search using the CDF II\nDetector in Run II of the Tevatron $p\\bar{p}$ collider. Such anomalous\nproduction could arise from various new physics processes. In a data sample\ncorresponding to 195 pb$^{-1}$ of integrated luminosity we predict 2.8$\\pm$0.5\nevents from Standard Model background processes and observe 4. We use this\nresult to set limits on the production of heavy scalar and vector particles\ndecaying to tau lepton pairs.", "category": "hep-ex" }, { "text": "Top quark properties measurement with the $D0$ detector: One of the main goals of the Tevatron RunII is to look for any hints for new\nphysics. At D0, the range of searches for new physics signals is large and one\nof the places we look for hints for new physics is by measuring the top quark\nproperties. A few of these measurements are discussed in this paper.", "category": "hep-ex" }, { "text": "Observation of di-structures in $e^+e^-\\rightarrow{J}/\u03c8{\\rm X}$ at\n center-of-mass energies around 3.773 GeV: We report a measurement of the observed cross sections of the inclusive\n$J/\\psi$ production in $e^+e^-\\rightarrow {J}/\\psi{\\rm X}$ based on 3.21\nfb$^{-1}$ of data accumulated at energies from 3.645 to 3.891 GeV with the\nBESIII detector operated at the BEPCII collider. The energy-dependent lineshape\nobtained from the measured cross sections cannot be well described by two\nBreit-Wigner (BW) amplitudes of the expected decays $\\psi(3686)\\rightarrow\n{J}/\\psi{\\rm X}$ and $\\psi(3770)\\rightarrow {J}/\\psi{\\rm X}$. Instead it can be\nbetter described with three BW amplitudes of the decays $\\psi(3686)\\rightarrow\n{J}/\\psi{\\rm X}$, $R(3760)\\rightarrow {J}/\\psi{\\rm X}$ and $R(3790)\\rightarrow\n{J}/\\psi{\\rm X}$ with two distinct structures referred to as $R(3760)$ and\n$R(3790)$. Under this assumption, we extracted their masses, total widths, and\nthe product of the leptonic width and decay branching fractions to be\n$M_{R(3760)}= {3761.7\\pm 2.2 \\pm 1.2}$ MeV/$c^2$, $\\Gamma^{\\rm tot}_{R(3760)}=\n{6.7\\pm 11.1 \\pm 1.1}$ MeV, $\\Gamma^{ee}_{R(3760)}\\mathcal B[R(3760)\\rightarrow\n{J}/\\psi {\\rm X}]=(4.0\\pm 4.3\\pm 1.2)$ eV, $M_{R(3790)} = {3784.7\\pm 5.7 \\pm\n1.6}$ MeV/$c^2$, $\\Gamma^{\\rm tot}_{R(3790)} = {31.6 \\pm 11.9 \\pm 3.2}$ MeV,\n$\\Gamma^{ee}_{R(3790)}\\mathcal B[R(3790)\\rightarrow {J}/\\psi {\\rm X}]=(18.1\\pm\n10.3\\pm 4.7)$ eV, where the first uncertainties are statistical and second\nsystematic.", "category": "hep-ex" }, { "text": "Study of particle production from quark and gluon jets in proton-proton\n collisions: We investigate whether and how different fragmentation properties of quarks\nand gluons affect identified particle spectra. We present a systematic study of\n$\\pi$, $K$ and $p$ production in minimum bias (inelastic, non-diffractive),\ntwo- and three-jet events at RHIC, Tevatron and LHC energies. Through the study\nof two- and three-jet events and various jet-production channels we can\ndirectly access the fragmentation properties of quark and gluon jets. We\npresent MC estimate for the contribution of quark and gluon jets to individual\nparticle species spectra, that can be compared to experimental results and test\nour current knowledge of the physics behind particle production inside jets.", "category": "hep-ex" }, { "text": "Machine learning approach for the search of resonances with topological\n features at the Large Hadron Collider: The observation of resonances is unequivocal evidence of new physics beyond\nthe Standard Model at the Large Hadron Collider (LHC). So far, inclusive and\nmodel dependent searches have not provided evidence of new resonances,\nindicating that these could be driven by subtle topologies. Here, we use\nmachine learning techniques based on weak supervision to perform searches. Weak\nsupervision based on mixed samples can be used to search for resonances with\nlittle or no prior knowledge on the production mechanism. Also, it offers the\nadvantage that sidebands or control regions can be used to effectively model\nbackgrounds with minimal reliance on simulations. However, weak supervision\nalone is found to be highly inefficient in identifying corners of the\nmulti-dimensional space of interest. Instead, we propose an approach to search\nfor new resonances that involves a classification procedure that is signature\nand topology based. A combination of weak supervision with Deep Neural Network\nalgorithms are applied following this classification. The performance of this\nstrategy is evaluated on the production of SM Higgs boson decaying to a pair of\nphotons inclusively and in exclusive regions of phase space tailored for\nspecific production modes at the LHC. After verifying the ability of the\nmethodology to extract different SM Higgs boson signal mechanisms, a search for\nnew phenomena in high-mass final states is setup for the LHC.", "category": "hep-ex" }, { "text": "Bilinear R Parity Violation at the ILC - Neutrino Physics at Colliders: Supersymmetry (SUSY) with bilinearly broken R parity (bRPV) offers an\nattractive possibility to explain the origin of neutrino masses and mixings. In\nsuch scenarios, the study of neutralino decays at colliders gives access to\nneutrino sector parameters. The ILC offers a very clean environment to study\nthe neutralino properties as well as its subsequent decays, which typically\ninvolve a $W$ or $Z$ boson and a lepton. This study is based on ILC beam\nparameters according to the Technical Design Report for a center of mass energy\nof $500\\,\\mathrm{GeV}$. A full detector simulation of the International Large\nDetector (ILD) was performed for all Standard Model backgrounds and for\n$\\widetilde{\\chi}_1^0$-pair production within a simplified model. The bRPV\nparameters are fixed according to current neutrino data. In this scenario, the\n$\\widetilde{\\chi}_1^0$ mass can be reconstructed with an uncertainty of $\\delta\nm = (40(\\text{stat.}) + 50(\\text{syst.}))\\,\\mathrm{MeV}$ for an integrated\nluminosity of $500\\,\\mathrm{fb}^{-1}$ from direct $\\widetilde{\\chi}_1^0$-pair\nproduction, thus, to a large extent independently of the rest of the SUSY\nspectrum. The achievable precision on the atmospheric neutrino mixing angle\n$\\sin^2 \\theta_{23}$ from measuring the neutralino branching fractions\n$\\mathrm{BR}(\\widetilde{\\chi}_1^0 \\rightarrow W \\mu)$ and\n$\\mathrm{BR}(\\widetilde{\\chi}_1^0 \\rightarrow W \\tau)$ at the ILC is better\nthan current uncertainties from neutrino experiments. Thus, the ILC could have\nthe opportunity to unveil the mechanism of neutrino mass generation.", "category": "hep-ex" }, { "text": "Search for exotics at $BABAR$: One of the most intriguing puzzles in hadron spectroscopy are the numerous\ncharmonium-like states observed in the last decade, including charged states\nthat are manifestly exotic. The $BABAR$ experiment has extensively studied\nthose in B meson decays, initial state radiation processes and two photon\nreactions. The study of the process $B \\rightarrow J/\\psi \\phi K$, with a\nsearch for the resonant states X(4140) and X(4270) in their decays to $J/\\psi\n\\phi$, will be highlighted. The recent results of the Dalitz analysis of\n$\\eta_c$ to 3 pseudoscalar mesons, via 2-photon interactions, will be presented\nin this report", "category": "hep-ex" }, { "text": "A Theory of Pattern Recognition for the Discrimination between Muon and\n Electron in the Super-Kamiokande: The standard Super-Kamiokande analysis uses an estimator for particle\nidentification by which it discriminates electrons (electron nutrinos) from\nmuons (muon nutrinos). Use of this estimator has led to the claim of a\nsignificant deficiency of muons (muon nutrinos), suggesting the existence of\nneutrino oscillations. We investigate three areas of concern for the\nSuper-Kamiokande estimator: the separation of the spatial part from the angular\npart in the probability functions, the neglect of fluctuations in the Cherenkov\nlight in different physical processes due to the charged particles concerned,\nand the point-like approximation for the emission of Cherenkov light. We show\nthat the first two factors are important for the consideration of stochastic\nprocesses in the generation of the Cherenkov light, and that the point-like\nassumption oversimplifies the estimation of the Cherenkov light quantities. We\ndevelop a new discrimination procedure for separating electron neutrinos from\nmuon neutrinos, based on detailed simulations carried out with GEANT~3.21 and\nwith newly derived mean angular distribution functions for the charged\nparticles concerned (muons and electrons/positrons), as well as the\ncorresponding functions for the relative fluctuations. These angular\ndistribution functions are constructed introducing a ``moving point''\napproximation. The application of our procedure between the discrimination\nbetween electron and muon to the analysis of the experimental data in SK will\nbe made in a subsequent paper.", "category": "hep-ex" }, { "text": "Search for a dark matter candidate produced in association with a single\n top quark in $p\\bar{p}$ collisions at $\\sqrt{s} = 1.96$ TeV: We report a new search for dark matter in a data sample of an integrated\nluminosity of 7.7 fb$^{-1}$ of Tevatron $p\\bar{p}$ collisions at $\\sqrt{s} =\n1.96$ TeV, collected by the CDF II detector. We search for production of a dark\nmatter candidate, $D$, in association with a single top quark. We consider the\nhadronic decay mode of the top quark exclusively, yielding a final state of\nthree jets with missing transverse energy. The data are consistent with the\nstandard model; we thus set 95% confidence level upper limits on the cross\nsection of the process $p\\bar{p}\\rightarrow t+D$ as a function of the mass of\nthe dark-matter candidate. The limits are approximately 0.5 pb for a\ndark-matter particle with mass in the range of 0-150 GeV/$c^{2}$.", "category": "hep-ex" }, { "text": "Detection of phi --> eta' photon, phi --> eta photon in pi+ pi- three\n photons final state with KLOE at DAFNE: KLOE has collected about 30 pb^-1 in year 2000 at the DAFNE collider, which\nyields the largest population of phi meson radiative decays studied so far. We\npresent the result obtained for phi-->eta photon and phi -->eta' photon: the\nratio of these two BR's has been measured to be (5.3 +- 0.5 +- 0.3) times\n10^-3, leading to a very accurate determination of the mixing angle in the\nflavor basis (40 +1.7 -1.5 degrees) and to the most accurate determination of\nBR(phi -->eta' photon) to date: (6.8 +- 0.6 +-0.5) times 10^-5.", "category": "hep-ex" }, { "text": "Open Heavy Flavor Production in p+p, d+Au and Au+Au Collisions at\n $\\sqrt(s)= 200$ GeV: PHENIX results for open charm production from semi-lepton decay in p+p, d+Au\nand Au+Au collisions in a wide rapidity ranges at $\\sqrt(s)= 200$ GeV are\npresented. Keywords: Relativistic Heavy-ion Collision, Open Charm production,\nNuclear Medium Effect PACS: 25.75.-q, 25.75 Dw, 13.20.Gd", "category": "hep-ex" }, { "text": "D0 status and first results from Run 2: In order to fully exploit the physics potential of the Tevatron Run 2, the D0\ndetector has been upgraded. Having nearly completed the commissioning phase,\nthe D0 detector is starting to produce its first physics results. An overview\nof the status of the main subdetectors involved in the upgrade is given,\nfollowed by some examples of preliminary physics results already emerging.", "category": "hep-ex" }, { "text": "Latest Constraints from Jet Measurements on Parton Distribution\n Functions and on the Strong Coupling Constant: Recent measurements of jet cross sections at HERA, the Tevatron and the LHC\nthat provide constraints on parton distribution functions and allow for\ndeterminations of the strong coupling constant are presented.", "category": "hep-ex" }, { "text": "Exploration of the Muon $g-2$ and Light Dark Matter explanations in NA64\n with the CERN SPS high energy muon beam: We report on a search for a new $Z'$ ($L_\\mu-L_\\tau$) vector boson performed\nat the NA64 experiment employing a high energy muon beam and a missing\nenergy-momentum technique. Muons from the M2 beamline at the CERN Super Proton\nSynchrotron with a momentum of 160 GeV/c are directed to an active target. A\nsignal event is a single scattered muon with momentum $<$ 80 GeV/c in the final\nstate, accompanied by missing energy, i.e. no detectable activity in the\ndownstream calorimeters. For a total statistic of $(1.98\\pm0.02)\\times10^{10}$\nmuons on target, no event is observed in the expected signal region. This\nallows us to set new limits on part of the remaining $(m_{Z'},\\ g_{Z'})$\nparameter space which could provide an explanation for the muon $(g-2)_\\mu$\nanomaly. Additionally, our study excludes part of the parameter space suggested\nby the thermal Dark Matter relic abundance. Our results pave the way to explore\nDark Sectors and light Dark Matter with muon beams in a unique and\ncomplementary way to other experiments.", "category": "hep-ex" }, { "text": "Evidence for hc Production from psi-prime at CLEO: Using the ~ 6 pb-1 of e+e- annihilation data taken at psi-prime(3686) with\nCLEO III and CLEO-c detectors with estimated ~ 3.0 million psi-prime events, we\nhave searched for the h_c(1^1P_1) state of charmonium in the reaction\npsi-prime(3686) -> pi^{0} hc -> (gamma gamma) (gamma eta_c). The preliminary\nresults are reported.", "category": "hep-ex" }, { "text": "Measurement of differential $t$-channel single top-quark production\n cross-sections with ATLAS: Absolute and normalised differential cross-sections of single top quarks\nproduced in the $t$-channel are presented. 20.2 fb$^{-1}$ of proton-proton\ncollision data at a centre-of-mass energy of 8 TeV collected by the ATLAS\nexperiment at the LHC are used. Differential cross-sections as a function of\nthe transverse momentum and the absolute value of the rapidity of the top\nquarks and the top antiquarks are measured at both parton level and particle\nlevel. The transverse momentum and rapidity differential cross-sections of the\nscattered light-quark jets are extracted at particle level. The measured\ncross-sections are compared to various Monte Carlo predictions as well as to\navailable fixed-order QCD calculations. All results agree with the Standard\nModel predictions.", "category": "hep-ex" }, { "text": "Searches for extra dimensions, gauge mediated SUSY and exotics at LEP: The results of searches for several type of physics beyond the Standard Model\nusing data from the four LEP experiments are presented. In the absence of any\nexcess signal events seen in the data limits are placed on the existence of\nextra-dimensions, gauge mediated supersymmetry and some exotic states.", "category": "hep-ex" }, { "text": "Overview of Deeply Virtual Compton Scattering at HERMES: Deeply Virtual Compton Scattering represents the best experimental channel\nthrough which to understand Generalised Parton Distributions. The HERMES\nexperiment measured the most diverse set of DVCS results of any experiment;\nthis talk discusses the most recent sets of DVCS results released by HERMES and\nthe unique experimental conditions found at HERMES that facilitated the\nmeasurements. We also examine the various ways in which the HERMES experimental\nmeasurements are being used to constrain GPDs and how future experiments can\nlearn from the HERMES program.", "category": "hep-ex" }, { "text": "Measurement of electroweak-induced production of W gamma with two jets\n in pp collisions at sqrt(s) = 8 TeV and constraints on anomalous quartic\n gauge couplings: A measurement of electroweak-induced production of W gamma and two jets is\nperformed, where the W boson decays leptonically. The data used in the analysis\ncorrespond to an integrated luminosity of 19.7 inverse femtobarns collected by\nthe CMS experiment in sqrt(s) = 8 TeV proton-proton collisions produced at the\nLHC. Candidate events are selected with exactly one muon or electron, missing\ntransverse momentum, one photon, and two jets with large rapidity separation.\nAn excess over the hypothesis of the standard model without electroweak\nproduction of W gamma with two jets is observed with a significance of 2.7\nstandard deviations. The cross section measured in the fiducial region is 10.8\n+/- 4.1 (stat) +/- 3.4 (syst) +/- 0.3 (lumi) fb, which is consistent with the\nstandard model electroweak predictions. The total cross section for W gamma\nproduction in association with 2 jets in the same fiducial region is measured\nto be 23.2 +/- 4.3 (stat) +/- 1.7 (syst) +/- 0.6 (lumi) fb, which is consistent\nwith the standard model prediction from the combination of electroweak- and\nquantum chromodynamics-induced processes. No deviations are observed from the\nstandard model predictions and experimental limits on anomalous quartic gauge\ncouplings f[M, 0-7] / Lambda^4, f[T, 0-2] / Lambda^4, and f[T, 5-7] / Lambda^4\nare set at 95% confidence level.", "category": "hep-ex" }, { "text": "Studies of heavy flavour production and the hadronic final state in high\n energy ep collisions: An extract of recent results from the H1 and ZEUS Collaborations is shown.\nVarious properties of quantum chromo dynamics are investigated by studying the\ndetails of the hadronic final state of high energy electron proton collisions\nat HERA. The presented results include analyses of jet cross sections and\nsingle particle production such as $\\gamma$ and $D$. Part of the measurements\ndeal with final states involving identified heavy quarks (charm and beauty).", "category": "hep-ex" }, { "text": "Recent Results in Semileptonic B Decays With BaBar: In this note, recent results of studies of semileptonic B meson decays from\n\\babar are discussed and preliminary results given. In particular, a recent\nmeasurement of $\\mathcal{B}(B \\to D^{(*)}\\tau \\nu)$ and the ratio\n$\\mathcal{B}(B \\to D^{(*)}\\tau \\nu)/\\mathcal{B}(B \\to D^{(*)}\\ell \\nu)$ is\npresented. For the $D^*$ mode, a branching fraction of\n$1.79\\pm0.13\\stat\\pm0.17\\syst$ is found, with a ratio of\n$0.325\\pm0.023\\stat\\pm0.027\\syst$. For the $D$ mode, the results are\n$1.04\\pm0.12\\stat\\pm0.14\\syst$ and $0.456\\pm0.053\\stat\\pm0.056\\syst$,\nrespectively. In addition, a study of $B_s$ production and semileptonic decays\nusing data collected in a center-of-mass energy region above the \\Y4S resonance\nis discussed. The semileptonic branching fraction $\\mathcal{B}(B_s \\to \\ell \\nu\nX)$ is measured to be $9.9{}^{+2.6}_{-2.1}\\stat{}^{+1.3}_{-2.0}\\syst$.", "category": "hep-ex" }, { "text": "Measurement of the Top Quark Mass with the Collider Detector at Fermilab: We present a new measurement of the top quark mass in $t\\bar t$ events in\nwhich both $W$ bosons from top quarks decay into lepton ($e \\nu,\\mu \\nu$).\n We use events collected by the CDF experiment from $p\\bar p$ collisions at\n\\sqrt s=1.8 TeV at the Tevatron collider. We measure a top quark mass of 167.4\n\\pm 10.3(stat) \\pm 4.8(syst) GeV/c^2 from a sample of eight events. We combine\nthis result with previous CDF measurements in other decay channels to obtain a\nmass value of 176.0 \\pm 6.5 GeV/c^2.", "category": "hep-ex" }, { "text": "Precision Determination of V_ub at an e+ e- B Factory: Current methods of determining V_ub are dominated by theoretical\nuncertainties. We present Monte Carlo simulations of three promising methods of\ndetermining V_ub with small theoretical and experimental errors. We find that\nwith data samples of order 1,000 fb-1 the B factories will attain combined\nexperimental errors of a few % on V_ub, much smaller than the theoretical\nerrors associated with new inclusive methods. Lattice QCD offers the promise of\nrate calculations of exclusive semileptonic decays with errors of a few %. A\ndata sample of order 10,000 fb-1, beyond the capabilities of the current B\nfactories, may be required to achieve an experimental error on the exclusive\nrate comparable to the theoretical error.", "category": "hep-ex" }, { "text": "The Need for an R&D and Upgrade Program for CMS Software and Computing: Over the next ten years, the physics reach of the Large Hadron Collider (LHC)\nat the European Organization for Nuclear Research (CERN) will be greatly\nextended through increases in the instantaneous luminosity of the accelerator\nand large increases in the amount of collected data. Due to changes in the way\nMoore's Law computing performance gains have been realized in the past decade,\nan aggressive program of R&D is needed to ensure that the computing capability\nof CMS will be up to the task of collecting and analyzing this data.", "category": "hep-ex" }, { "text": "Measurement of Ratios of $\u03bd_\u03bc$ Charged-Current Cross Sections on\n C, Fe, and Pb to CH at Neutrino Energies 2-20 GeV: We present measurements of $\\nu_{\\mu}$ charged-current cross section ratios\non carbon, iron, and lead relative to a scintillator (CH) using the\nfine-grained MINERvA detector exposed to the NuMI neutrino beam at Fermilab.\nThe measurements utilize events of energies $2=8~GeV$, which have a reconstructed $\\mu^{-}$ scattering angle\nless than $17^\\circ$ to extract ratios of inclusive total cross sections as a\nfunction of neutrino energy $E_{\\nu}$ and flux-integrated differential cross\nsections with respect to the Bjorken scaling variable $x$. These results\nprovide the first high-statistics direct measurements of nuclear effects in\nneutrino scattering using different targets in the same neutrino beam. Measured\ncross section ratios exhibit a relative depletion at low $x$ and enhancement at\nlarge $x$. Both become more pronounced as the nucleon number of the target\nnucleus increases. The data are not reproduced by GENIE, a conventional\nneutrino-nucleus scattering simulation, or by the alternative models for the\nnuclear dependence of inelastic scattering that are considered.", "category": "hep-ex" }, { "text": "Recent Top Properties Measurements at CDF: We present the most recent CDF results in the measurements of the decay and\nproduction vertex of the top-quark. New results on forward-backward asymmetry\nin top-antitop events are presented. Also, recent measurements of the branching\nfractions of top-quark are discussed. Finally, measurements in single top\nevents, where top-quark is produced through electroweak processes, are\npresented. Despite the much larger number of top events collected at the LHC,\ndue to the symmetric initial state and the better signal-to-background ratio in\nspecific channels, some results will be lasting heritage of the Tevatron.", "category": "hep-ex" }, { "text": "Study of the tau- --> 3h-2h+nu Decay: The branching fraction of the tau- --> 3h- 2h+ nu decay (h= pi, kaon) is\nmeasured with the BaBar detector to be (8.56 +/- 0.05 +/- 0.42)E-04 where the\nfirst error is statistical and the second systematic. The observed structure of\nthis decay is significantly different from the phase space prediction, with the\nrho resonance playing a strong role. The decay tau- --> f1 pi nu with the f1\nmeson decaying to four charged pions, is observed and the branching fraction is\nmeasured to be (3.9 +/- 0.7 +/- 0.5)E-04.", "category": "hep-ex" }, { "text": "New precise determination of the \u03c4lepton mass at KEDR detector: The status of the experiment on the precise $\\tau$ lepton mass measurement\nrunning at the VEPP-4M collider with the KEDR detector is reported. The mass\nvalue is evaluated from the $\\tau^+\\tau^-$ cross section behaviour around the\nproduction threshold. The preliminary result based on 6.7 pb$^{-1}$ of data is\n$m_{\\tau}=1776.80^{+0.25}_{-0.23} \\pm 0.15$ MeV. Using 0.8 pb$^{-1}$ of data\ncollected at the $\\psi'$ peak the preliminary result is also obtained:\n$\\Gamma_{ee}B_{\\tau\\tau}(\\psi') = 7.2 \\pm 2.1$ eV.", "category": "hep-ex" }, { "text": "Measuring the tau polarization at ILC: Measurement of the tau lepton polarization in \\eett\\ is an important\nelectro-weak measurement at ILC and other future electron-positron colliders.\nIn this paper we discuss several methods to extract polarimeter information for\n\\eett\\ events at the nominal centre-of-mass energy, and develop a new method,\nbased on charged particle impact parameter measurement, which can accurately\nreconstruct tau momenta even in events with significant Initial State\nRadiation.\n In future work we will extend the study to estimate the precision with which\nthe tau polarization can be measured at ILC-250, both for high-mass tau pairs\nand for those which radiatively return to the $Z^0$ peak. This will complement\nour past study which showed that the tau polarization can be measured to better\nthan 1\\% at the ILC-500.", "category": "hep-ex" }, { "text": "Single Spin Asymmetry of Charged Hadron Production by 40 GeV/c Polarized\n Protons: The single spin asymmetry for charge hadron production off nuclei (C, Cu) has\nbeen measured using 40 GeV/c polarized proton beam.\n The measurements were carried out using FODS-2 experimental setup at\n IHEP. The data are presented in the central region and the forward region\nwith respect to the incident protons.", "category": "hep-ex" }, { "text": "First Search for the $K_L \\to \u03c0^0 \u03b3$ Decay: We report the first search for the $K_L \\to \\pi^0 \\gamma$ decay, which is\nforbidden by Lorentz invariance, using the data from 2016 to 2018 at the J-PARC\nKOTO experiment. With a single event sensitivity of $(7.1\\pm 0.3_{\\rm stat.}\n\\pm 1.6_{\\rm syst.})\\times 10^{-8}$, no candidate event was observed in the\nsignal region. The upper limit on the branching fraction was set to be\n$1.7\\times 10^{-7}$ at the 90\\% confidence level.", "category": "hep-ex" }, { "text": "Preliminary Measurement of the Differential Cross Section from\n Neutrino-Nucleon Deeply Inelastic Scattering at Nutev: Preliminary results for the neutrino-nucleon differential cross section from\nthe NuTeV experiment are presented. The extraction of the differential cross\nsection from NuTeV is discussed and the structure functions $F_2$ and $\\Delta\nxF_3$ are presented. Comparisons are made with CCFR results.", "category": "hep-ex" }, { "text": "C$^3$: A \"Cool\" Route to the Higgs Boson and Beyond: We present a proposal for a cold copper distributed coupling accelerator that\ncan provide a rapid route to precision Higgs physics with a compact 8 km\nfootprint. This proposal is based on recent advances that increase the\nefficiency and operating gradient of a normal conducting accelerator. This\ntechnology also provides an $e^{+}e^{-}$ collider path to physics at multi-TeV\nenergies. In this article, we describe our vision for this technology and the\nnear-term R&D program needed to pursue it.", "category": "hep-ex" }, { "text": "Study of the structure of e+e- -> b bbar g events and improved limits on\n the anomalous chromomagnetic coupling of the b-quark: The structure of e+e- -> bbg events was studied using Z0 decays recorded in\nthe SLD experiment at SLAC. Three-jet final states were selected and the\nCCD-based vertex detector was used to identify two of the jets as b or bbar.\nDistributions of the gluon energy and polar angle were measured over the full\nkinematic range, and compared with perturbative QCD predictions. The energy\ndistribution is potentially sensitive to an anomalous b chromomagnetic moment\nkappa. We measured kappa to be consistent with zero and set limits on its\nvalue, -0.11 < kappa < 0.08 at 95% c.l. (preliminary).", "category": "hep-ex" }, { "text": "Jet Charge with the ATLAS Detector using $\\sqrt{s}=8$ TeV $pp$ Collision\n Data: The momentum-weighted sum of the charges of tracks associated to a jet\nprovides an experimental handle on the electric charge of fundamental\nstrongly-interacting particles. An overview of a study of this jet charge\nobservable for jets produced in dijet and semileptonic $t\\bar{t}$ events using\n$5.8$ $\\mathrm{fb}^{-1}$ of data with the ATLAS detector at $\\sqrt{s}=8$ TeV is\ndescribed here. In addition to providing a constraint on hadronization models,\njet charge has many possible applications in measurements and searches. The\nmodelling of jet charge and its performance as a charge-tagger are studied in\norder to establish this observable as a tool for future physics analyses.", "category": "hep-ex" }, { "text": "Measurement of the forward-backward asymmetry in $Z/\u03b3^{\\ast}\n \\rightarrow \u03bc^{+}\u03bc^{-}$ decays and determination of the effective weak\n mixing angle: The forward-backward charge asymmetry for the process $q\\bar{q} \\rightarrow\nZ/\\gamma^{\\ast} \\rightarrow \\mu^{+}\\mu^{-}$ is measured as a function of the\ninvariant mass of the dimuon system. Measurements are performed using proton\nproton collision data collected with the LHCb detector at $\\sqrt{s} = 7$ and\n8\\tev, corresponding to integrated luminosities of $1$fb$^{-1}$ and\n$2$fb$^{-1}$ respectively. Within the Standard Model the results constrain the\neffective electroweak mixing angle to be $$sin^{2}\\theta_{W}^{eff} = 0.23142\n\\pm 0.00073 \\pm 0.00052 \\pm 0.00056 $$ where the first uncertainty is\nstatistical, the second systematic and the third theoretical. This result is in\nagreement with the current world average, and is one of the most precise\ndeterminations at hadron colliders to date.", "category": "hep-ex" }, { "text": "Measurement of D^0 and D^+ meson masses with the KEDR Detector: The masses of the neutral and charged D-mesons have been measured with the\nKEDR detector at the VEPP-4M electron-positron collider:\n M(D^0) = 1865.30 +- 0.33 +- 0.23 MeV,\n M(D^+) = 1869.53 +- 0.49 +- 0.20 MeV.", "category": "hep-ex" }, { "text": "Experimental review of unpolarised nucleon structure functions: Recent results are reviewed on unpolarised structure functions from fixed\ntarget experiments at JLAB, NuTeV and from the HERA ep collider experiments H1\nand ZEUS.", "category": "hep-ex" }, { "text": "Measurement of B+ -> K+ tau- tau+, B -> K* l+ l- and B -> K pi+ pi-\n gamma decays at BABAR: We present some recent measurements of rare flavor-changing neutral current B\ndecays, using data collected with the BABAR detector at the PEP-II e+e-\ncollider at SLAC. First, we search for the rare process B+ -> K+ tau- tau+ and\nwe do not find evidence for signal. The measured branching fraction is\n(1.31+0.66-0.61(stat.)+0.35-0.25(sys.)) x 10-3 with an upper limit, at the 90%\nconfidence level, of B(B+ -> K+ tau+ tau-) < 2.25 x 10-3. We then study the\nlepton forward-backward asymmetry AFB and the longitudinal K* polarization FL\nin the rare decays B -> K* l+ l-, where l+ l- is either e+ e- or mu+ mu-. We\nreport results for both the K*(892)0l+l- and K*(892)+l+l- final states, as well\nas their combination K*l+l-, in five disjoint dilepton mass-squared bins.\nFinally, we measure the time-dependent CP asymmetry in the radiative-penguin\ndecay B0 -> KS0 pi- pi+ gamma. The Kpipi resonant structure is extracted by an\namplitude analysis of the m_Kpipi and m_Kpi spectra in B+ -> K+ pi- pi+ gamma\ndecays. We use these results to extract the mixing-induced CP parameters of the\nprocess B0 -> KS rho gamma from the time-dependent analysis of B0 -> KS0 pi+\npi- gamma decays and obtain S = -0.18 pm 0.32(stat.) +0.06 -0.05(syst.).", "category": "hep-ex" }, { "text": "Muon identification using multivariate techniques in the CMS experiment\n in proton-proton collisions at $\\sqrt{s}$ = 13 TeV: The identification of prompt and isolated muons, as well as muons from\nheavy-flavour hadron decays, is an important task. We developed two\nmultivariate techniques to provide highly efficient identification for muons\nwith transverse momentum greater than 10 GeV. One provides a continuous\nvariable as an alternative to a cut-based identification selection and offers a\nbetter discrimination power against misidentified muons. The other one selects\nprompt and isolated muons by using isolation requirements to reduce the\ncontamination from nonprompt muons arising in heavy-flavour hadron decays. Both\nalgorithms are developed using 59.7 fb$^{-1}$ of proton-proton collisions data\nat a centre-of-mass energy of $\\sqrt{s}$ = 13 TeV collected in 2018 with the\nCMS experiment at the CERN LHC.", "category": "hep-ex" }, { "text": "Observation of $Z_c(3900)^{0}$ in $e^+e^-\\to\u03c0^0\u03c0^0 J/\u03c8$: Using a data sample collected with the BESIII detector operating at the\nBEPCII storage ring, we observe a new neutral state $Z_c(3900)^{0}$ with a\nsignificance of $10.4\\sigma$. The mass and width are measured to be\n$3894.8\\pm2.3\\pm3.2$ MeV/$c^2$ and $29.6\\pm8.2\\pm8.2$~MeV, respectively, where\nthe first error is statistical and the second systematic. The Born cross\nsection for $e^+e^-\\to\\pi^0\\pi^0 J/\\psi$ and the fraction of it attributable to\n$\\pi^0 Z_c(3900)^{0}\\to\\pi^0\\pi^0 J/\\psi$ in the range $E_{cm}=4.19-4.42$ GeV\nare also determined. We interpret this state as the neutral partner of the\nfour-quark candidate $Z_c(3900)^\\pm$.", "category": "hep-ex" }, { "text": "Measurement of branching fractions for\n $\u03c8(3686)\\rightarrow\u03b3\u03b7',\u03b3\u03b7$ and $\u03b3\u03c0^{0}$: Using a data sample of $448\\times10^{6}$ $\\psi(3686)$ events collected with\nthe BESIII detector operating at the BEPCII storage ring, the decays\n$\\psi(3686)\\rightarrow\\gamma\\eta$ and $\\psi(3686)\\rightarrow\\gamma\\pi^{0}$ are\nobserved with a statistical significance of $7.3\\sigma$ and $ 6.7\\sigma$,\nrespectively. The branching fractions are measured to be\n$\\mathcal{B}(\\psi(3686)\\rightarrow\\gamma\\eta)=(0.85\\pm0.18\\pm0.05)\\times10^{-6}$\nand\n$\\mathcal{B}(\\psi(3686)\\rightarrow\\gamma\\pi^{0})=(0.95\\pm0.16\\pm0.05)\\times10^{-6}$.\nIn addition, we measure the branching fraction of\n$\\psi(3686)\\rightarrow\\gamma\\eta'$ to be\n$\\mathcal{B}(\\psi(3686)\\rightarrow\\gamma\\eta')=(125.1\\pm2.2\\pm6.2)\\times\n10^{-6}$, with improved precision compared to previous results.", "category": "hep-ex" }, { "text": "TAU 98 Conference Summary: I very briefly review the highlights of the fifth workshop on the physics of\nthe tau lepton and its neutrino. There has been much progress in many\nsub-fields, which I touch upon in this review: the couplings of the tau to the\n$Z^0$ and $W^\\pm$; the leptonic branching fractions, lifetime, and tests of\nuniversality; the Lorentz structure of tau decays; searches for neutrinoless\ndecays; limits on weak and electromagnetic dipole moments and CP violation;\ninclusive semi-hadronic decays, spectral functions, sum rules, QCD, and\napplications; substructure in tau decays to three pseudoscalars; tau decays to\nkaons; limits on the mass of the tau neutrino; tau neutrinos from solar,\natmospheric, and AGN sources; accelerator searches for neutrino oscillations;\nand prospects for the future.", "category": "hep-ex" }, { "text": "Search for the Standard Model Higgs Boson Produced in Association with a\n $Z$ Boson in $p\\bar{p}$ Collisions at $\\sqrt{s} = 1.96$ TeV: We present a search for the standard model Higgs boson produced in\nassociation with a $Z$ boson, using up to 7.9 fb$^{-1}$ of integrated\nluminosity from $p\\bar{p}$ collisions collected with the CDF II detector. We\nutilize several novel techniques, including multivariate lepton selection,\nmultivariate trigger parametrization, and a multi-stage signal discriminant\nconsisting of specialized functions trained to distinguish individual\nbackgrounds. By increasing acceptance and enhancing signal discrimination,\nthese techniques have significantly improved the sensitivity of the analysis\nabove what was expected from a larger dataset alone. We observe no significant\nevidence for a signal, and we set limits on the $ZH$ production cross section.\nFor a Higgs boson with mass 115 GeV/$c^2$, we expect (observe) a limit of 3.9\n(4.8) times the standard model predicted value, at the 95% credibility level.", "category": "hep-ex" }, { "text": "Performance of b-tagging algorithms at the CMS experiment with pp\n collision data at $\\sqrt s$=8 TeV: The identification of jets originating from b quarks is crucial both for the\nsearches for new physics and for the measurement of standard model processes.\nThe Compact Muon Solenoid (CMS) collaboration at the Large Hadron Collider\n(LHC) has developed a variety of algorithms to select b-quark jets based on\nvariables such as the impact parameter of charged particle tracks, properties\nof reconstructed secondary vertices from heavy hadron decays, and the presence\nor absence of a lepton in the jet, or combinations thereof. Performance\nmeasurements of these b-jet identification algorithms are presented, using\nmultijet and $t\\overline{t}$ events recorded in proton-proton collision data at\n$\\sqrt s$=8 TeV with the CMS detector during the LHC Run 1.", "category": "hep-ex" }, { "text": "Study of the mass and spin-parity of the Higgs boson candidate via its\n decays to Z boson pairs: A study is presented of the mass and spin-parity of the new boson recently\nobserved at the LHC at a mass near 125 GeV. An integrated luminosity of 17.3\ninverse femtobarns, collected by the CMS experiment in proton-proton collisions\nat center-of-mass energies of 7 and 8 TeV, is used. The measured mass in the ZZ\nchannel, where both Z bosons decay to e or mu pairs, is 126.2 +/- 0.6 (stat.)\n+/- 0.2 (syst.) GeV. The angular distributions of the lepton pairs in this\nchannel are sensitive to the spin-parity of the boson. Under the assumption of\nspin 0, the present data are consistent with the pure scalar hypothesis, while\ndisfavoring the pure pseudoscalar hypothesis.", "category": "hep-ex" }, { "text": "Analysis of the $Wtb$ vertex from the measurement of triple-differential\n angular decay rates of single top quarks produced in the $t$-channel at\n $\\sqrt{s}$ = 8 TeV with the ATLAS detector: The electroweak production and subsequent decay of single top quarks in the\n$t$-channel is determined by the properties of the $Wtb$ vertex, which can be\ndescribed by the complex parameters of an effective Lagrangian. An analysis of\na triple-differential decay rate in $t$-channel production is used to\nsimultaneously determine five generalised helicity fractions and phases, as\nwell as the polarisation of the produced top quark. The complex parameters are\nthen constrained. This analysis is based on 20.2 fb$^{-1}$ of proton-proton\ncollision data at a centre-of-mass energy of 8 TeV collected with the ATLAS\ndetector at the LHC. The fraction of decays containing transversely polarised\n$W$ bosons is measured to be $f_1=0.30 \\pm 0.05$. The phase between amplitudes\nfor transversely and longitudinally polarised $W$ bosons recoiling against\nleft-handed $b$-quarks, is measured to be $\\delta_- =\n0.002\\pi^{+0.016\\pi}_{-0.017\\pi}$, giving no indication of CP violation. The\nfraction of longitudinal or transverse $W$ bosons accompanied by right-handed\n$b$-quarks are also constrained. Based on these measurements, limits are placed\nat 95% C.L. on the ratio of the complex coupling parameters\nRe$[g_\\mathrm{R}/V_\\mathrm{L}] \\in [-0.12,0.17]$ and\nIm$[g_\\mathrm{R}/V_\\mathrm{L}] \\in [-0.07,0.06]$. Constraints are also placed\non the ratios $|V_\\mathrm{R}/V_\\mathrm{L}|$ and $|g_\\mathrm{L}/V_\\mathrm{L}|$.\nIn addition, the polarisation of single top quarks in the $t$-channel is\nconstrained to be $P > 0.72$ (95% C.L.). None of the above measurements make\nassumptions on the value of any of the other parameters or couplings and all of\nthem are in agreement with the Standard Model.", "category": "hep-ex" }, { "text": "AMANDA: Status and latest Results: We briefly review some of the recent AMANDA results emphasizing the all\nflavor capabilities of the high energy neutrino telescope, important in the\ncontext of equal neutrino mixing from distant sources at Earth. Together with a\nreport on a preliminary UHE neutrino flux limit, the course of our progress in\nthe quest for point sources is described. Finally, a 1 year preliminary limit\nof AMANDA-II to neutralino cold dark matter (CDM) candidates, annihilating in\nthe center of the Sun, for various MSSM parameter choices is presented and\ndiscussed.", "category": "hep-ex" }, { "text": "Neutrino Reconstruction in TRIDENT Based on Graph Neural Network: TRopIcal DEep-sea Neutrino Telescope (TRIDENT) is a next-generation neutrino\ntelescope to be located in the South China Sea. With a large detector volume\nand the use of advanced hybrid digital optical modules (hDOMs), TRIDENT aims to\ndiscover multiple astrophysical neutrino sources and probe all-flavor neutrino\nphysics. The reconstruction resolution of primary neutrinos is on the critical\npath to these scientific goals. We have developed a novel reconstruction method\nbased on graph neural network (GNN) for TRIDENT. In this paper, we present the\nreconstruction performance of the GNN-based approach on both track- and\nshower-like neutrino events in TRIDENT.", "category": "hep-ex" }, { "text": "First Measurement of \u03b8_13 from Delayed Neutron Capture on Hydrogen\n in the Double Chooz Experiment: The Double Chooz experiment has determined the value of the neutrino\noscillation parameter $\\theta_{13}$ from an analysis of inverse beta decay\ninteractions with neutron capture on hydrogen. This analysis uses a three times\nlarger fiducial volume than the standard Double Chooz assessment, which is\nrestricted to a region doped with gadolinium (Gd), yielding an exposure of\n113.1 GW-ton-years. The data sample used in this analysis is distinct from that\nof the Gd analysis, and the systematic uncertainties are also largely\nindependent, with some exceptions, such as the reactor neutrino flux\nprediction. A combined rate- and energy-dependent fit finds $\\sin^2\n2\\theta_{13}=0.097\\pm 0.034(stat.) \\pm 0.034 (syst.)$, excluding the\nno-oscillation hypothesis at 2.0 \\sigma. This result is consistent with\nprevious measurements of $\\sin^2 2\\theta_{13}$.", "category": "hep-ex" }, { "text": "B Physics (Experiment): In past few years the flavor physics made important transition from the work\non confirmation the standard model of particle physics to the phase of search\nfor effects of a new physics beyond standard model. In this paper we review\ncurrent state of the physics of b-hadrons with emphasis on results with a\nsensitivity to new physics.", "category": "hep-ex" }, { "text": "CP violation results from CDF: We present world-leading results on CP-violating asymmetries and branching\nfractions of several decay modes of B0, B0s, and {\\Lambda}b hadrons into\ncharmless two-body, and of B\\pm into charm, final states collected by the CDF\ndetector. We also report a new measurement of CP-violating asymmetries in\nD\\ast\\pm-tagged D0 \\rightarrow h+h- (h = K or {\\pi}) decays, where any\nenhancement from the Standard Model prediction would be unambiguous evidence\nfor New Physics.", "category": "hep-ex" }, { "text": "Probing Dark Universe with Exceptional Points: It is demonstrated that detection of putative particles such as paraphotons\nand axions constituting the dark sector of the universe can be reduced to\ndetection of extremely weak links or couplings between cavities and modes. This\nmethod allows utilisation of extremely sensitive frequency metrology methods\nthat are not limited by traditional requirements on ultra low temperatures,\nstrong magnetic fields and sophisticated superconducting technology. We show\nthat exceptional points in the eigenmode structure of coupled modes may be used\nto boost the sensitivity of dark matter mediated weak links. We find\nobservables that are proportional to fractional powers of fundamental coupling\nconstants. Particularly, in the case of axion detection, it is demonstrated\nthat resonance frequency scaling with $\\sim \\sqrt{g_{a\\gamma\\gamma}\\theta}$ and\n$\\sim \\sqrt[3]{g_{a\\gamma\\gamma}\\theta}$ dependencies can be realised in a\nternary photonic cavity system, which is beneficial as these coupling constants\nare extremely small.", "category": "hep-ex" }, { "text": "Search for a new pseudoscalar decaying into a pair of muons in events\n with a top-quark pair at $\\sqrt{s} = 13$ TeV with the ATLAS detector: A search for a new pseudoscalar $a$-boson produced in events with a top-quark\npair, where the $a$-boson decays into a pair of muons, is performed using\n$\\sqrt{s} = 13$ TeV $pp$ collision data collected with the ATLAS detector at\nthe LHC, corresponding to an integrated luminosity of $139\\, \\mathrm{fb}^{-1}$.\nThe search targets the final state where only one top quark decays to an\nelectron or muon, resulting in a signature with three leptons $e\\mu\\mu$ and\n$\\mu\\mu\\mu$. No significant excess of events above the Standard Model\nexpectation is observed and upper limits are set on two signal models: $pp\n\\rightarrow t\\bar{t}a$ and $pp \\rightarrow t\\bar{t}$ with $t \\rightarrow H^\\pm\nb$, $H^\\pm \\rightarrow W^\\pm a$, where $a\\rightarrow\\mu\\mu$, in the mass ranges\n$15$ GeV $ < m_a < 72$ GeV and $120$ GeV $ \\leq m_{H^{\\pm}} \\leq 160$ GeV.", "category": "hep-ex" }, { "text": "Search for heavy resonances decaying to WW, WZ, or WH boson pairs in a\n final state consisting of a lepton and a large-radius jet in proton-proton\n collisions at $\\sqrt{s}$ = 13 TeV: A search for new heavy resonances decaying to pairs of bosons (WW, WZ, or WH)\nis presented. The analysis uses data from proton-proton collisions collected\nwith the CMS detector at a center-of-mass energy of 13 TeV, corresponding to an\nintegrated luminosity of 137 fb$^{-1}$. One of the bosons is required to be a W\nboson decaying to an electron or muon and a neutrino, while the other boson is\nrequired to be reconstructed as a single jet with mass and substructure\ncompatible with a quark pair from a W, Z, or Higgs boson decay. The search is\nperformed in the resonance mass range between 1.0 and 4.5 TeV and includes a\nspecific search for resonances produced via vector boson fusion. The signal is\nextracted using a two-dimensional maximum likelihood fit to the jet mass and\nthe diboson invariant mass distributions. No significant excess is observed\nabove the estimated background. Model-independent upper limits on the\nproduction cross sections of spin-0, spin-1, and spin-2 heavy resonances are\nderived as functions of the resonance mass and are interpreted in the context\nof bulk radion, heavy vector triplet, and bulk graviton models. The reported\nbounds are the most stringent to date.", "category": "hep-ex" }, { "text": "Inclusive production of D*+- mesons in photon-photon collisions at\n sqrt(s) = 183 and 189 GeV and a first measurement of the the charm structure\n function of the photon: The inclusive production of D*+- mesons in photon-photon collisions has been\nmeasured using the OPAL detector at LEP at e+e- centre-of-mass energies of 183\nand 189GeV. The D* mesons are reconstructed in their decay to D0pi+ with the D0\nobserved in the two decay modes Kpi+ and Kpi+pi-pi+. After background\nsubtraction, 100.4+-12.6(stat) D*+- mesons have been selected in events without\nobserved scattered beam electron (\"anti-tagged\") and 29.8+-5.9 (stat) D*+-\nmesons in events where one beam electron is scattered into the detector\n(\"single-tagged\"). Direct and single-resolved events are studied separately.\nDifferential cross-sections as functions of the D* transverse momentum p_t and\npseudorapidity \\eta are presented in the kinematic region 2hh Decays at the $\u03a5(5S)$ Resonance: We have searched for B_{s}^{0}->hh decays, where h stands for a charged or\nneutral kaon, or a charged pion. These results are based on a 23.6 fb^{-1} data\nsample collected with the Belle detector on the \\Upsilon(5S) resonance at the\nKEKB asymmetric-energy e^{+}e^{-} collider, containing 1.25x10^6\nB_{s}^{(*)}\\bar{B}_{s}^{(*)} events. We observe the decay B_{s}^{0}->K^{+}K^{-}\nand measure its branching fraction, \\mathcal{B}(B_{s}^{0}->K^{+}K^{-}) =\n[3.8_{-0.9}^{+1.0}(\\mathrm{stat})\\pm 0.5(\\mathrm{syst})\\pm 0.5(f_s)] \\times\n10^{-5}. The first error is statistical, the second is systematic, and the\nthird error is due to the uncertainty in the B^0_s production fraction in\n$e^+e^-\\to b\\bar{b}$ events. No significant signals are seen in other decay\nmodes, and we set upper limits at 90% confidence level:\n\\mathcal{B}(B_{s}^{0}->K^-\\pi^{+})< 2.6 \\times 10^{-5},\n\\mathcal{B}(B_{s}^{0}->\\pi^{+}\\pi^{-})< 1.2 \\times 10^{-5} and\n\\mathcal{B}(B_{s}^{0}->K^0\\bar{K}^0) < 6.6\\times 10^{-5}.", "category": "hep-ex" }, { "text": "Experimental overview of charmonium spectroscopy: In this talk, I review the recent experimental results on charmonium\nspectroscopy from BESIII, Belle, BaBar and CLEOc. Below the open-charm\nthreshold, the masses and widths of spin-singlet states eta_c, eta_c(2S), h_c\nare measured with high precision. Above the threshold, chi_{c2}(2P) is\nidentified in the process gamma gamma -> chi_{c2}(2P) -> gamma D bar{D};\nEvidence of X(3823) is found in the M(chi_{c1} gamma) invariant-mass\ndistribution for B -> gamma chi_{c1} K decays, the measured properties are\nconsistent with the missing psi_2(1^{2}D_2) state.", "category": "hep-ex" }, { "text": "Search for heavy neutrinos at CERN SPS: The phenomenology in the neutrino sector requires physics beyond the Standard\nModel. One possibility is the existence of new massive leptonic states which\ncould be probed at the high intensity machines. The present results on heavy\nneutral leptons from the study of kaon decays in flight with the NA48/2 and\nNA62 experiments are presented and the future prospects for such searches at\nCERN SPS are discussed.", "category": "hep-ex" }, { "text": "Status of LHCb: The status of the LHCb experiment is presented. The experiment has been\ntaking data since the LHC startup. The performances of the various\nsub-detectors are discussed and a preliminary measurement of the b\ncross-section is reported. The value is in agreement with expectations.", "category": "hep-ex" }, { "text": "DM+$b\\bar b$ simulations with DMSimp: an update: Searches for dark matter (DM) produced using collider data probe wide regions\nof the allowed parameter space of many models and have become competitive with\nmore traditional searches. The interpretations of the results can be\nefficiently performed in simplified models, which feature only a mediator and a\nDM candidate together with the interactions among them and the standard model\nparticles. The DMSimp model in FeynRules currently features a wide set of\n$s$-channel simplified models and can be exploited by the MadGraph5_aMC@NLO\nframework to produce event samples including NLO QCD corrections for realistic\nsimulations. Higher-order corrections typically have a sizeable impact on the\ntotal production rate and lead to a reduction of the theoretical uncertainties.\nIn this short note we report on a recent update of the DMSimp model, which\nmakes it possible to simulate dark matter production in association with bottom\nquarks in a mixed four-flavour scheme, where the $\\overline{\\rm MS}$\nrenormalisation for the bottom-quark Yukawa is employed, while the bottom quark\nmass is on shell. By comparing with five-flavour scheme, we show that the mixed\nfour-flavor scheme provides reliable predictions for DM+$b\\bar b$ final states\nin a wide range of DM masses.", "category": "hep-ex" }, { "text": "Measurements of branching fractions, rate asymmetries, and angular\n distributions in the rare decays B --> Kl+l- and B --> K*l+l-: We present measurements of the flavor-changing neutral current decays B -->\nKl+l- and B --> K*l+l-, where l+l- is either an e+e- or mu+mu- pair. The data\nsample comprises 229 x 10^6 Y(4s) -->to BBbar decays collected with the BaBar\ndetector at the PEP-II e+e- storage ring. Flavor-changing neutral current\ndecays are highly suppressed in the Standard Model and their predicted\nproperties could be significantly modified by new physics at the electroweak\nscale. We measure the branching fractions B(B --> Kll) = (0.34 +- 0.07 +- 0.02)\nx 10^{-6}, B(B --> K*ll) = (0.78^{+0.19}_{-0.17} +- 0.11) x 10^{-6}, the direct\nCP asymmetries of these decays, and the relative abundances of decays to\nelectrons and muons. For two regions in l+l- mass, above and below m(Jpsi), we\nmeasure partial branching fractions and the forward-backward angular asymmetry\nof the lepton pair. In these same regions we also measure the K* longitudinal\npolarization in B --> K*l+l- decays. Upper limits are obtained for the lepton\nflavor-violating decays B --> Kemu and B --> K*emu. All measurements are\nconsistent with Standard Model expectations.", "category": "hep-ex" }, { "text": "Vector Boson + Heavy Flavor Jets Production at the Tevatron: Recent measurements on the vector boson plus heavy-flavor jets production by\nthe CDF and D0 experiments are presented in comparisons with recent theoretical\npredictions. Good understanding of such processes is important to improve our\nunderstanding of QCD and also to enhance the potential to search for\nyet-to-be-discovered new physics phenomena which lead to similar final states.", "category": "hep-ex" }, { "text": "First measurement of charm production in fixed-target configuration at\n the LHC: The first measurement of heavy-flavour production by the LHCb experiment in\nits fixed-target mode is presented. The production of $J/\\psi$ and $D^0$ mesons\nis studied with beams of protons of different energies colliding with gaseous\ntargets of helium and argon with nucleon-nucleon centre-of-mass energies of\n$\\sqrt{s_{NN}} = 86.6 $ and $ 110.4$ ${\\rm GeV}$, respectively. The $J/\\psi$\nand $D^0$ (including charge conjugate) production cross sections in $p{\\rm He}$\ncollisions in the rapidity range $[2,4.6]$ are found to be $\\sigma_{J/\\psi} =\n652 \\pm 33$ (stat) $\\pm 42$ (syst) nb$/$nucleon and $\\sigma_{D^0} = 80.8 \\pm\n2.4$ (stat) $\\pm 6.3$ (syst) $\\mu$b$/$nucleon, where the first uncertainty is\nstatistical and the second is systematic. No evidence for a substantial\nintrinsic charm content of the nucleon is observed in the large Bjorken-$x$\nregion.", "category": "hep-ex" }, { "text": "Measurements of the CKM angle gamma using B^+ --> D K^+ decays at LHCb: Of the three angles that make up the CKM matrix, the least well known is\ngamma. A precision measurement of this quantity is highly desirable as it forms\none of the arbitrary parameters in the Standard Model. Moreover, this is the\none angle of the CKM triangle that can be determined in channels that occur via\ntree-level decays. While loop-level processes could have sensitivity to physics\nbeyond the standard model, tree level processes are expected to be unaltered.\nHence a measurement of gamma in tree level processes leads to a standard model\nbenchmark measurement against which other loop-driven measurements can be\ncompared. The measurements described here are the latest developments from LHCb\ninvolving the decay B^+ --> D K^+, where the D meson is either a D^0 or a\nanti-D^0 and the final state of the D meson is accessible from either flavour\nstate.", "category": "hep-ex" }, { "text": "Discovery potential for heavy t-tbar resonances in dilepton+jets final\n states: We examine the prospects for probing heavy top quark-antiquark (t-tbar)\nresonances at the upgraded LHC in pp collisions at $\\root_s = 14 TeV. Heavy\nt-tbar resonances (Z' bosons) are predicted by several theories that go beyond\nthe standard model. We consider scenarios in which each top quark decays\nleptonically, either to an electron or a muon, and the data sets correspond to\nintegrated luminosities of \\int L dt = 300 /fb and \\int L dt = 3000 /fb. We\npresent the expected 5-sigma discovery potential for a Z' resonance as well as\nthe expected upper limits at 95% C.L. on the Z' production cross section and\nmass in the absence of a discovery.", "category": "hep-ex" }, { "text": "Measurement of neutrino source activity in the experiment BEST by\n calorimetric method: Experiments to study non-standard properties of neutrinos using\nhigh-intensity artificial neutrino sources require high accuracy in determining\ntheir activity. A calorimetric system to determine the activity of a 51Cr\nneutrino source in the experiment BEST with an accuracy better than 1% was\ncreated. The design of the calorimetric system and the main factors affecting\nthe accuracy of measurements are considered. The results of measurements of the\nactivity of the source made for the BEST experiment are presented. The value of\nthe source activity from calorimetric measurements was 3.41 MCi at the\nbeginning of the experiment.", "category": "hep-ex" }, { "text": "Observation of Time-Dependent CP Violation in B0 -> eta' K0 Decays and\n Improved Measurements of CP Asymmetries in B0 -> phiK0, KsKsKs and B0 ->\n J/psi K0 Decays: We present improved measurements of CP-violation parameters in B0->phiK0,\neta'K0, KsKsKs decays based on a sample of 535x10^6 BBbar pairs collected at\nthe Y(4S) resonance with the Belle detector at the KEKB energy-asymmetric e+e-\ncollider. We obtain sin2phi_1^eff=+0.64+-0.10(stat)+-0.04(syst) for B0->eta'K0,\n+0.50+-0.21(stat)+-0.06(syst) for B0->phiK0, and +0.30+-0.32(stat) +-0.08(syst)\nfor B0->KsKsKs decays. We have observed CP violation in the B0->eta'K0 decay\nwith a significance of 5.6 standard deviations. We also perform an improved\nmeasurement of CP asymmetries in B0->J/psiK0 decays and obtain\nsin2phi_1=+0.642+- 0.031(stat)+-0.017(syst).", "category": "hep-ex" }, { "text": "Recent Studies of Exotic Hadrons at the LHCb Experiment: Recent results on studies of exotic hadrons at the LHCb experiment are\nsummarised. These are the observation of new resonances decaying to J/$\\psi\nK^{+}$ and J/$\\psi\\phi$, evidence of a J/$\\psi\\Lambda$ structure and\nobservation of excited $\\Xi^{-}$ states in the $\\Xi_{b}^{-}\\to J/\\psi \\Lambda\nK^{-}$ decay and the study of $B_{s}^{0}\\to J/\\psi\\pi^{+}\\pi^{-}K^{+}K^{-}$\ndecays.", "category": "hep-ex" }, { "text": "Measurements of the Higgs boson production and decay rates and\n constraints on its couplings from a combined ATLAS and CMS analysis of the\n LHC $pp$ collision data at $\\sqrt{s}=$ 7 and 8 TeV: Combined ATLAS and CMS measurements of the Higgs boson production and decay\nrates, as well as constraints on its couplings to vector bosons and fermions,\nare presented. The combination is based on the analysis of five production\nprocesses, namely gluon fusion, vector boson fusion, and associated production\nwith a $W$ or a $Z$ boson or a pair of top quarks, and of the six decay modes\n$H \\to ZZ, WW$, $\\gamma\\gamma, \\tau\\tau, bb$, and $\\mu\\mu$. All results are\nreported assuming a value of 125.09 GeV for the Higgs boson mass, the result of\nthe combined measurement by the ATLAS and CMS experiments. The analysis uses\nthe CERN LHC proton--proton collision data recorded by the ATLAS and CMS\nexperiments in 2011 and 2012, corresponding to integrated luminosities per\nexperiment of approximately 5 fb$^{-1}$ at $\\sqrt{s}=7$ TeV and 20 fb$^{-1}$ at\n$\\sqrt{s} = 8$ TeV. The Higgs boson production and decay rates measured by the\ntwo experiments are combined within the context of three generic\nparameterisations: two based on cross sections and branching fractions, and one\non ratios of coupling modifiers. Several interpretations of the measurements\nwith more model-dependent parameterisations are also given. The combined signal\nyield relative to the Standard Model prediction is measured to be 1.09 $\\pm$\n0.11. The combined measurements lead to observed significances for the vector\nboson fusion production process and for the $H \\to \\tau\\tau$ decay of $5.4$ and\n$5.5$ standard deviations, respectively. The data are consistent with the\nStandard Model predictions for all parameterisations considered.", "category": "hep-ex" }, { "text": "Search for Violation of CPT and Lorentz Invariance in $B^0_s$ Meson\n Oscillations using the D0 Detector: A search is presented for CPT-violating effects in the mixing of $B^0_s$\nmesons using the D0 detector at the Fermilab Tevatron Collider. The\nCPT-violating asymmetry in the decay $B^0_s \\rightarrow \\mu^{\\pm} D_s^{\\mp} X$\nas a function of sidereal phase is measured. No evidence for CPT-violating\neffects is observed and limits are placed on CPT- and Lorentz-invariance\nviolating coupling coefficients.", "category": "hep-ex" }, { "text": "Experimental Review of Structures in the $J/\u03c8\u03c6$ Mass Spectrum: The discovery of numerous new charmonium-like structures since 2003 have\nrevitalized interest in exotic meson spectroscopy. These structures do not fit\neasily into the conventional charmonium model, and proposals like four-quark\nstates, hybrids, and re-scattering effects have been suggested as explanations.\nSince 2009, several new structures were reported in the $J/\\psi\\phi$ mass\nspectrum with the following characteristics: they are the first ones reported\ndecaying into two heavy mesons which contain both a $c\\bar{c}$ pair and a\n$s\\bar{s}$ pair; and their masses are well beyond the open charm pair\nthreshold. Conventional $c\\bar{c}$ states with a mass beyond the $J/\\psi\\phi$\nthreshold are not expected to decay into this channel and the width is expected\nto be large, thus they are good candidates for exotic mesons. My focus in this\narticle is to review the recent developments on the structures in the\n$J/\\psi\\phi$ mass spectrum from CDF, Belle and LHCb.", "category": "hep-ex" }, { "text": "Precision measurement of the top-quark mass in lepton+jets final states: We measure the mass of the top quark in lepton$+$jets final states using the\nfull sample of $p\\bar{p}$ collision data collected by the D0 experiment in Run\nII of the Fermilab Tevatron Collider at $\\sqrt s=1.96 $TeV, corresponding to\n$9.7 {\\rm fb}^{-1}$ of integrated luminosity. We use a matrix element technique\nthat calculates the probabilities for each event to result from $t\\bar t$\nproduction or background. The overall jet energy scale is constrained in situ\nby the mass of the $W$ boson. We measure $m_t=174.98\\pm0.76$ GeV. This\nconstitutes the most precise single measurement of the top-quark mass.", "category": "hep-ex" }, { "text": "A Review of chi_cJ Decays at BESIII and CLEO-c: The latest results on chi_cJ(1P) decays from BESIII and CLEO-c are reviewed\nand compared to theoretical predictions. The experimental results use the final\nsamples of chi_cJ(1P) decays from CLEO-c, obtained from 26 million psi(2S)\ndecays, and the most recent samples from BESIII, from a starting sample of 106\nmillion psi(2S) decays.", "category": "hep-ex" }, { "text": "Search for the exotic $\u039e^{--}(1860)$ Resonance in 340GeV/c\n $\u03a3^-$-Nucleus Interactions: We report on a high statistics search for the $\\Xi^{--}(1860)$ resonance in\n$\\Sigma^-$-nucleus collisions at 340GeV/c. No evidence for this resonance is\nfound in our data sample which contains 676000 $\\Xi^-$ candidates above\nbackground. For the decay channel $\\Xi^{--}(1860) \\to \\Xi^-\\pi^-$ and the\nkinematic range 0.15$\n np\u03c0^+\u03c0^-$ at Pn=3.83 Gev/c: This work is devoted to search and study scalar $\\sigma_0 0^+[0^++]$ - mesons\nin the system of $\\pi^+\\pi^-$ from the reaction $np -> np\\pi^+\\pi^-$ at the\nimpulse of the quasimonochromatic neutrons c from the data obtained in an\nexposure of the 1m H2 bubble chamber of LHE (JINR)The resonance with and has\nbeen found out in effective mass distribution. Value of a statistical deviation\nof this peculiarity from a background is more than four. Spin of the resonance\nhas been estimated, which, with high probability, is equal 0. The other quantum\nnumbers of the resonance have been estimated.", "category": "hep-ex" }, { "text": "A study of meson and baryon decays to strange final states with GlueX in\n Hall D (A proposal to the 39th Jefferson Lab Program Advisory Committee): The primary motivation of the GlueX experiment is to search for and\nultimately study the pattern of gluonic excitations in the meson spectrum\nproduced in gamma p collisions. Recent lattice QCD calculations predict a rich\nspectrum of hybrid mesons that have both exotic and non-exotic JPC,\ncorresponding to q q-bar (q=u, d, or s) states coupled with a gluonic field. A\nthorough study of the hybrid spectrum, including the identification of the\nisovector triplet, with charges 0 and +-1, and both isoscalar members, |s\ns-bar> and |u u-bar> + |d d-bar>, for each predicted hybrid combination of JPC,\nmay only be achieved by conducting a systematic amplitude analysis of many\ndifferent hadronic final states. We propose the development of a kaon\nidentification system, supplementing the existing GlueX forward time-of-flight\ndetector, in order to cleanly select meson and baryon decay channels that\ninclude kaons. Once this detector has been installed and commissioned, we plan\nto collect a total of 200 days of physics analysis data at an average intensity\nof 5 x 10^7 tagged photons on target per second. This data sample will provide\nan order of magnitude statistical improvement over the initial GlueX data set\nand, with the developed kaon identification system, a significant increase in\nthe potential for GlueX to make key experimental advances in our knowledge of\nhybrid mesons and Cascade baryons.", "category": "hep-ex" }, { "text": "Search for the Standard Model Higgs boson in WH -> lnubb and H -> WW(*)\n -> lnulnu channels at ATLAS: Results for the Standard Model Higgs boson search by the ATLAS experiment in\nthe WH -> lnubb and H -> WW(*) -> lnulnu channels are presented. The results\nare based on 1.04 fb^-1 of data from pp collisions at sqrt(s) = 7 TeV produced\nby the LHC in 2011. No evidence is found for the Standard Model Higgs boson in\neither decay mode. The WH -> lnubb channel is not yet sensitive to the Standard\nModel Higgs, while the H -> WW(*) -> lnulnu channel excludes the Standard Model\nHiggs in the range of 158 < m_H < 186 GeV at the 95% confidence level.", "category": "hep-ex" }, { "text": "Inclusive Hadron Production and Dijets at HERA: This article summarizes a talk given at the International Symposium on\nMultiparticle Dynamics 1999 in Providence/USA. It provides an overview on the\nvariety of measurements of the hadronic final state in jet production for\ndeep-inelastic scattering and photoproduction at HERA.", "category": "hep-ex" }, { "text": "Angular Intermittency and Analytical QCD Predictions: We present a comparison of local multiplicity fluctuations in angular\nphase-space intervals with first-order QCD predictions. The data are based on\n810k hadronic events at 91.2 GeV collected with the L3 detector at LEP during\n1994.", "category": "hep-ex" }, { "text": "Significant Excess of ElectronLike Events in the MiniBooNE\n Short-Baseline Neutrino Experiment: The MiniBooNE experiment at Fermilab reports results from an analysis of\n$\\nu_e$ appearance data from $12.84 \\times 10^{20}$ protons on target in\nneutrino mode, an increase of approximately a factor of two over previously\nreported results. A $\\nu_e$ charged-current quasielastic event excess of $381.2\n\\pm 85.2$ events ($4.5 \\sigma$) is observed in the energy range\n$200 W+W- at a High Energy\n Electron-Positron Linear Collider: The study of the process $e^+e^- \\to W^+W^-$ at Linear Collider energies\npresents a good opportunity to investigate anomalous triple gauge boson\ncouplings and $W^+_LW^-_L$ rescattering. The helicity analysis of the $e^+e^-\n\\to W^+_LW^-_L$ decays will benefit if the charm quark containing jet can be\nidentified for events which contain one hadronic $W$ boson decay to a charm and\nanother quark. A JAVA implementation of the SLD collaboration's topological\nvertex finding algorithm (ZVTOP) in the linear collider analysis framework has\nbeen used to extract charm tag efficiencies and purities based on vertex\nmultiplicities.", "category": "hep-ex" }, { "text": "B-tagging in CMS: The identification of b jets is a crucial issue to study and characterize\nvarious channels like top quark events and many new physics scenarios.\nDifferent b-tagging techniques are defined in CMS which benefit from the long\nlife time, high mass and large momentum fraction of the b-hadron produced in\nb-quark jet. Effcient algorithms have been developed based on the measure of\nb-hadron secondary vertex or on tracks with a large impact parameter. Data\ncollected in pp collisions at 7TeV in 2011 are used to estimate both the\nb-tagging effciency and the mistag rate from light flavor jets.", "category": "hep-ex" }, { "text": "DAMA/LIBRA results and perspectives: The DAMA/LIBRA experiment ($\\sim$ 250 kg of highly radio-pure NaI(Tl)) is\nrunning deep underground at the Gran Sasso National Laboratory (LNGS) of the\nI.N.F.N. Here we briefly recall the results obtained in its first phase of\nmeasurements (DAMA/LIBRA--phase1, total exposure: 1.04 ton $\\times$ yr).\nDAMA/LIBRA--phase1 and the former DAMA/NaI (cumulative exposure: $1.33$ ton\n$\\times$ yr) give evidence at 9.3 $\\sigma$ C.L. for the presence of DM\nparticles in the galactic halo by exploiting the model-independent DM annual\nmodulation signature. No systematic or side reaction able to mimic the\nexploited DM signature has been found or suggested by anyone over more than a\ndecade. At present DAMA/LIBRA--phase2 is running with increased sensitivity.", "category": "hep-ex" }, { "text": "Top FCNC searches at HL-LHC with the CMS experiment: The Large Hadron Collider is the world's largest and highest center-of-mass\nenergy particle accelerator. During the Phase I operation it is expected that\nthe LHC operated at a centre-of-mass energy of 13 TeV will deliver to the CMS\nexperiment total integrated luminosity of $\\sim$300 fb$^{-1}$ till 2023. The\nHigh Luminosity LHC upgrade is expected to run at a centre-of-mass energy of 14\nTeV and will allow ATLAS and CMS to collect integrated luminosities of the\norder of 300 fb$^{-1}$ per year, and up to 3000 fb$^{-1}$ during the HL-LHC\nprojected lifetime of ten years. The large expected integrated luminosity\nenables the exploration of the multi-TeV scale by searches for particles with\nhigh masses as well as by investigation of processes with very low cross\nsections such as Flavor-Change Neutral Current interactions in top quark\nsector. In this report we present a proposal for the top quark FCNC searches at\nHL-LHC based on Monte-Carlo simulation of the upgraded CMS detector.", "category": "hep-ex" }, { "text": "Search for long-lived neutral particles in $pp$ collisions at $\\sqrt{s}$\n = 13 TeV that decay into displaced hadronic jets in the ATLAS calorimeter: This paper describes a search for pairs of neutral, long-lived particles\ndecaying in the ATLAS calorimeter. Long-lived particles occur in many\nextensions to the Standard Model and may elude searches for new promptly\ndecaying particles. The analysis considers neutral, long-lived scalars with\nmasses between 5 GeV and 400 GeV, produced from decays of heavy bosons with\nmasses between 125 GeV and 1000 GeV, where the long-lived scalars decay into\nStandard Model fermions. The analysis uses either 10.8 fb$^{-1}$ or 33.0\nfb$^{-1}$ of data (depending on the trigger) recorded in 2016 at the LHC with\nthe ATLAS detector in proton-proton collisions at a centre-of-mass energy of 13\nTeV. No significant excess is observed, and limits are reported on the\nproduction cross section times branching ratio as a function of the proper\ndecay length of the long-lived particles.", "category": "hep-ex" }, { "text": "Results of the NEMO3 experiment: The purpose of the NEMO3 experiment is to detect neutrinoless double beta\ndecay in order to determine the nature of neutrino and its absolute mass. We\nanalysed the 389 effective days of data from the $\\sim 7$ kg of $^{100}$Mo and\n$\\sim 1$ kg of $^{82}$Se and obtained the following limits on the half-life for\nthe \\bb process: $T_{1/2}(\\beta\\beta0 \\nu) > 4.6 \\times 10^{23}$ years (Mo) and\n$T_{1/2}(\\beta \\beta 0 \\nu) > 1.0 \\times 10^{23}$ years (Se). The corresponding\nlimits on the neutrino effective mass are $ <$ 0.7 - 2.8 eV (Mo) and\n$ >$ 1.7 - 4.9 eV (Se) at 90% Confident Level. We also performed a\ndetailled analysis on the double beta decay of $^{100}$Mo into the excited\nstates $0^+_1$, $2^+_1$ of $^{100}$Ru. The results are: $T_{1/2}(\\beta \\beta 2\n\\nu \\to 0^+_1) = 5.7^{+1.3}_{-0.9}(stat)\\pm 0.7 (syst) \\times 10^{20}$ years,\n$T_{1/2}(\\beta \\beta 2 \\nu \\to 2^+_1) > 1.1 \\times 10^{21}$ years,\n$T_{1/2}(\\beta \\beta 0 \\nu \\to 0^+_1) > 8.9 \\times 10^{22}$ years,\n$T_{1/2}(\\beta \\beta 0 \\nu \\to 2^+_1) > 1.6 \\times 10^{23}$ years.", "category": "hep-ex" }, { "text": "Search for the Decay tau- --> 3pi- 2pi+ 2pi0 nu_tau: A search for the decay of the tau lepton to five charged and two neutral\npions is performed using data collected by the BABAR detector at the PEP-II\nasymmetric-energy e+e- collider. The analysis uses 232 fb-1 of data at\ncenter-of-mass energies on or near the Y(4S) resonance. We observe 10 events\nwith an expected background of 6.5^{+2.0}_{-1.4} events. In the absence of a\nsignal, we set the limit on the branching ratio B(tau- --> 3pi- 2pi+ 2pi0\nnu_tau) < 3.4x10^{-6} at the 90% confidence level. This is a significant\nimprovement over the previously established limit. In addition, we search for\nthe decay mode tau- --> 2omega pi- nu_tau. We observe 1 event with an expected\nbackground of 0.4^{+1.0}_{-0.4} events and calculate the upper limit B(tau- -->\n2omega pi- nu_tau) < 5.4x10^{-7} at the 90% confidence level. This is the first\nupper limit for this mode.", "category": "hep-ex" }, { "text": "Differential cross sections of the charge-exchange reaction pi- p -->\n pi0 n in the momentum range from 103 to 178 MeV/c: Measured values of the differential cross sections for pion-nucleon charge\nexchange, pi- p --> pi0 n, are presented for pi- momenta of 103, 112, 120, 130,\n139, 152, and 178 MeV/c. Complete angular distributions were obtained by using\nthe Crystal Ball detector at the Alternating Gradient Synchrotron at Brookhaven\nNational Laboratory. Statistical uncertainties of the differential cross\nsections vary from 3% to 6% in the backward angle region, and from 6% to about\n20% in the forward region with the exception of the two most forward angles.\nThe systematic uncertainties are estimated to be about 3% for all momenta.", "category": "hep-ex" }, { "text": "Total Cross Section of the Process e+e- -> pi+pi-pi+pi- in the\n C.M.Energy Range 980-1380 MeV: The e+e- -> pi+pi-pi+pi- cross section has been measured using 5.8/pb of\nintegrated luminosity collected with the CMD-2 detector at the VEPP-2M\ncollider. Analysis of the data with a refined efficiency determination and use\nof both three- and four-track events allowed doubling of a data sample and\nreduction of systematic errors to 5-7%.", "category": "hep-ex" }, { "text": "Latest Results from the MiniBooNE Experiment and Updated Oscillation\n Sensitivity: Neutrino oscillations have been established in solar and atmospheric\nneutrinos, but a third signal from the LSND experiment is incompatible with\nthree Standard Model neutrinos. The MiniBooNE experiment can confirm or refute\nthe LSND oscillation signal with 1E21 protons on target. Preliminary results on\nmuon neutrino analyses and an updated oscillation sensitivity are presented.", "category": "hep-ex" }, { "text": "Multivariate Techniques for Identifying Diffractive Interactions at the\n LHC: Close to one half of the LHC events are expected to be due to elastic or\ninelastic diffractive scattering. Still, predictions based on extrapolations of\nexperimental data at lower energies differ by large factors in estimating the\nrelative rate of diffractive event categories at the LHC energies. By\nidentifying diffractive events, detailed studies on proton structure can be\ncarried out.\n The combined forward physics objects: rapidity gaps, forward multiplicity and\ntransverse energy flows can be used to efficiently classify proton-proton\ncollisions. Data samples recorded by the forward detectors, with a simple\nextension, will allow first estimates of the single diffractive (SD), double\ndiffractive (DD), central diffractive (CD), and non-diffractive (ND) cross\nsections. The approach, which uses the measurement of inelastic activity in\nforward and central detector systems, is complementary to the detection and\nmeasurement of leading beam-like protons.\n In this investigation, three different multivariate analysis approaches are\nassessed in classifying forward physics processes at the LHC. It is shown that\nwith gene expression programming, neural networks and support vector machines,\ndiffraction can be efficiently identified within a large sample of simulated\nproton-proton scattering events. The event characteristics are visualized by\nusing the self-organizing map algorithm.", "category": "hep-ex" }, { "text": "Search for CP violation in D+ -> phi pi+ and Ds+ -> Ks pi+ decays: A search for CP violation in D+ -> phi pi+ decays is performed using data\ncollected in 2011 by the LHCb experiment corresponding to an integrated\nluminosity of 1.0 fb^{-1} at a centre of mass energy of 7 TeV. The CP-violating\nasymmetry is measured to be (-0.04+/-0.14+/-0.14)% for candidates with K-K+\nmass within 20 MeV/c^{2} of the phi meson mass. A search for a CP-violating\nasymmetry that varies across the phi mass region of the D+ -> K-K+pi+ Dalitz\nplot is also performed, and no evidence for CP violation is found. In addition,\nthe CP asymmetry in the Ds+ -> Ks pi+ decay is measured to be\n(0.61+/-0.83+/-0.14)%.", "category": "hep-ex" }, { "text": "B Physics (Experiment): In past few years the flavor physics made important transition from the work\non confirmation the standard model of particle physics to the phase of search\nfor effects of a new physics beyond standard model. In this paper we review\ncurrent state of the physics of b-hadrons with emphasis on results with a\nsensitivity to new physics.", "category": "hep-ex" }, { "text": "Forward Pion Production in p+p and d+Au Collisions at STAR: Measurements are reported of the production of high energy pi-zero mesons\nfrom the STAR experiment in p+p and d+Au collisions at sqrt(s_NN)=200 GeV and\n=4.00 (d beam direction). The inclusive yield agrees with perturbative QCD\ncalculations in p+p collisions, but is found to be reduced in d+Au collisions.\nThe azimuthal correlations of the forward pi-zero with charged hadrons at\nmidrapidity agree with PYTHIA in p+p collisions, but are suppressed in d+Au\ncollisions. The results are consistent with the conjecture that the gluon\ndensity in nuclei is suppressed.", "category": "hep-ex" }, { "text": "Search for pair production of first-generation scalar leptoquarks at\n $\\sqrt{s} =$ 13 TeV: A search for the pair production of first-generation scalar leptoquarks is\nperformed using proton-proton collision data recorded at 13 TeV center-of-mass\nenergy with the CMS detector at the LHC. The data correspond to an integrated\nluminosity of 35.9 fb$^{-1}$. The leptoquarks are assumed to decay to a quark,\nand either an electron or a neutrino with branching fractions $\\beta$ and\n1$-\\beta$, respectively. The search targets the decay final states comprising\ntwo electrons, or one electron and large missing transverse momentum, along\nwith two quarks that are detected as hadronic jets. First-generation scalar\nleptoquarks with masses below 1435 (1270) GeV are excluded for $\\beta =$ 1.0\n(0.5). These are the most stringent limits on the mass of first-generation\nscalar leptoquarks to date. The data are also interpreted to set exclusion\nlimits in the context of an $R$-parity violating supersymmetric model,\npredicting promptly decaying top squarks with a similar dielectron final state.", "category": "hep-ex" }, { "text": "Searches for Majorana Neutrinos and Direct Searches for Exotics at LHCb: These proceedings present the LHCb results on Majorana neutrino searches and\ndirect production of exotic particles using the data collected during Run I of\nLHC. For the former, Majorana neutrinos are searched for both on-shell and\noff-shell in $B$ and $D$ decays to final states with two same-sign muons. For\nthe latter, different types of new particles are studied profiting the unique\ncoverage of LHCb with respect to other detectors.", "category": "hep-ex" }, { "text": "Muon $g-2$: A review: The muon magnetic anomaly, $a_{\\mu}=(g_{\\mu}-2)/2$, plays a special role in\nthe history of the Standard Model (SM). Precise calculations and measurements\nof this fundamental quantity provide a stringent test of the SM and a window to\nthe physics beyond. In light of the first result published by the Fermilab Muon\n$g-2$ experiment, this article reviews the current status of the experimental\nmeasurement and theoretical prediction of the muon anomalous magnetic moment.\nIt also provides an overview on resulting constraints of associated physics\nbeyond the SM (BSM), future muon $g-2$ experiments, and on the progress of\nexperiments that are closely connected to the physics of the muon $g-2$, such\nas measurements that could provide complementary information about BSM physics\nin the muon sector.", "category": "hep-ex" }, { "text": "First Measurement of Monoenergetic Muon Neutrino Charged Current\n Interactions: We report the first measurement of monoenergetic muon neutrino charged\ncurrent interactions. MiniBooNE has isolated 236 MeV muon neutrino events\noriginating from charged kaon decay at rest ($K^+ \\rightarrow \\mu^+ \\nu_\\mu$)\nat the NuMI beamline absorber. These signal $\\nu_\\mu$-carbon events are\ndistinguished from primarily pion decay in flight $\\nu_\\mu$ and\n$\\overline{\\nu}_\\mu$ backgrounds produced at the target station and decay pipe\nusing their arrival time and reconstructed muon energy. The significance of the\nsignal observation is at the 3.9$\\sigma$ level. The muon kinetic energy,\nneutrino-nucleus energy transfer ($\\omega=E_\\nu-E_\\mu$), and total cross\nsection for these events is extracted. This result is the first known-energy,\nweak-interaction-only probe of the nucleus to yield a measurement of $\\omega$\nusing neutrinos, a quantity thus far only accessible through electron\nscattering.", "category": "hep-ex" }, { "text": "Amplitude analysis of $D_s^{+} \\rightarrow \u03c0^{+} \u03c0^{-} \u03c0^{+}$: Utilizing the data set corresponding to an integrated luminosity of $3.19$\nfb$^{-1}$ collected by the BESIII detector at a center-of-mass energy of 4.178\nGeV, we perform an amplitude analysis of the $D_s^+\\to\\pi^+\\pi^-\\pi^+$ decay.\nThe sample contains 13,797 candidates with a signal purity of $\\sim$80%. The\namplitude and phase of the contributing $\\pi\\pi$ ${\\cal S}$ wave are measured\nbased on a quasi-model-independent approach, along with the amplitudes and\nphases of the ${\\cal P}$ and ${\\cal D}$ waves parametrized by Breit-Wigner\nmodels. The fit fractions of different intermediate decay channels are also\nreported.", "category": "hep-ex" }, { "text": "Reply to 'Corrections to the HARP-CDP Analysis of the LSND Neutrino\n Oscillation Backgrounds': The alleged mistakes in recent papers that reanalyze the backgrounds to the\n'LSND anomaly' do not exist. We maintain our conclusion that the significance\nof the 'LSND anomaly' is not 3.8 sigma but not larger than 2.3 sigma.", "category": "hep-ex" }, { "text": "Top mass measurements: The top quark mass measurements are based either on a direct kinematic\nreconstruction of the top quark decay products or on indirect measurements,\nwhere an observable sensitive to the top quark mass, such as the production\ncross section, is used to infer it. The ATLAS and CMS collaborations have\nmeasured the top quark mass using various methods with increasing precision.\nRecent measurements using 13 TeV pp collision data recorded at the LHC are\npresented in this review.", "category": "hep-ex" }, { "text": "Top Quark Pair Production Cross-Section Measurements at DO: We present recent measurements of the top quark pair production cross-section\nin the dilepton, lepton+jets and lepton+tau final states with the D0 detector\nin $p\\bar{p}$ collisions at $\\sqrt{s}=1.96$ TeV.", "category": "hep-ex" }, { "text": "The E6 inspired isosinglet quark and the Higgs boson: We consider the experimental implications of the down type isosinglet quark,\n$D$, predicted by the $E_{6}$, group to Higgs boson searches at the LHC. The\npair production of $D$ quarks at the LHC and their subsequent decays $D\\to h d$\nand $D\\to W u$ has been analyzed. For a light Higgs boson of mass O(120 GeV),\nan analysis based on fast simulation of the ATLAS detector response shows that,\nthe $b\\bar{b}$ channel becomes as efficient as the $\\gamma\\gamma$ channel for\ndiscovering the Higgs particle if $m_{D}<630$ GeV.", "category": "hep-ex" }, { "text": "Search for ZZ and Z\u03b3^* production in p-barp collisions at sqrt(s) =\n 1.96 TeV and limits on anomalous ZZZ and ZZ\u03b3^* couplings: We present a study of four muon, four electron, and two muon two electron\nevents using 1 fb^(-1) of data collected with the D0 detector at the Fermilab\nTevatron p-barp Collider at sqrt(s) = 1.96 TeV. Requiring the lepton pair\nmasses to be greater than 30 GeV, we observe one event, consistent with the\nexpected background of 0.13 +- 0.03 events and with the predicted standard\nmodel ZZ and Z\\gamma^* production of 1.71 +-0.15 events. We set an upper limit\non the ZZ and Z\\gamma^* cross section of 4.4 pb at the 95% C.L. We also derive\nlimits on anomalous neutral trilinear ZZZ and ZZ\\gamma^* gauge couplings. The\none-parameter 95%$ C.L. coupling limits with a form factor scale Lambda = 1.2\nTeV are -0.28 < f_(40)^Z < 0.28, -0.31 < f_(50)^Z < 0.29, -0.26 < f_(40)^\\gamma\n< 0.26, and -0.30 < f_(5 0)^\\gamma < 0.28.", "category": "hep-ex" }, { "text": "The BABAR Detector: BABAR, the detector for the SLAC PEP-II asymmetric e+e- B Factory operating\nat the upsilon 4S resonance, was designed to allow comprehensive studies of\nCP-violation in B-meson decays. Charged particle tracks are measured in a\nmulti-layer silicon vertex tracker surrounded by a cylindrical wire drift\nchamber. Electromagentic showers from electrons and photons are detected in an\narray of CsI crystals located just inside the solenoidal coil of a\nsuperconducting magnet. Muons and neutral hadrons are identified by arrays of\nresistive plate chambers inserted into gaps in the steel flux return of the\nmagnet. Charged hadrons are identified by dE/dx measurements in the tracking\ndetectors and in a ring-imaging Cherenkov detector surrounding the drift\nchamber. The trigger, data acquisition and data-monitoring systems, VME- and\nnetwork-based, are controlled by custom-designed online software. Details of\nthe layout and performance of the detector components and their associated\nelectronics and software are presented.", "category": "hep-ex" }, { "text": "Diffraction and Total Cross-Section at the Tevatron and the LHC: At the Tevatron, the total p_bar-p cross-section has been measured by CDF at\n546 GeV and 1.8 TeV, and by E710/E811 at 1.8 TeV. The two results at 1.8 TeV\ndisagree by 2.6 standard deviations, introducing big uncertainties into\nextrapolations to higher energies. At the LHC, the TOTEM collaboration is\npreparing to resolve the ambiguity by measuring the total p-p cross-section\nwith a precision of about 1 %. Like at the Tevatron experiments, the\nluminosity-independent method based on the Optical Theorem will be used. The\nTevatron experiments have also performed a vast range of studies about soft and\nhard diffractive events, partly with antiproton tagging by Roman Pots, partly\nwith rapidity gap tagging. At the LHC, the combined CMS/TOTEM experiments will\ncarry out their diffractive programme with an unprecedented rapidity coverage\nand Roman Pot spectrometers on both sides of the interaction point. The physics\nmenu comprises detailed studies of soft diffractive differential\ncross-sections, diffractive structure functions, rapidity gap survival and\nexclusive central production by Double Pomeron Exchange.", "category": "hep-ex" }, { "text": "Search for $C\\!P$ violation in $\u039b^0_b \\to p K^-$ and $\u039b^0_b\n \\to p \u03c0^-$ decays: A search for $C\\!P$ violation in $\\Lambda^0_b \\to p K^-$ and $\\Lambda^0_b \\to\np \\pi^-$ decays is presented using a sample of $pp$ collisions collected with\nthe LHCb detector and corresponding to an integrated luminosity of 3.0\nfb$^{-1}$. The $C\\!P$-violating asymmetries are measured to be\n$A_{\\mathrm{CP}}^{pK^-} = -0.020 \\pm 0.013\\pm 0.019$ and\n$A_{\\mathrm{CP}}^{p\\pi^-} = -0.035 \\pm 0.017 \\pm 0.020 $, and their difference\n$A_{\\mathrm{CP}}^{pK^-}-A_{\\mathrm{CP}}^{p\\pi^-} = 0.014 \\pm 0.022 \\pm 0.010$,\nwhere the first uncertainties are statistical and the second systematic. These\nare the most precise measurements of such asymmetries to date.", "category": "hep-ex" }, { "text": "A stronger classical definition of Confidence Limits: A novel way of defining limits in classical statistics is proposed. This is a\nnatural extension of the original Neyman's method, and has the desirable\nproperty that only information relevant to the problem is used in making\nstatistical inferences. The result is a strong restriction on the allowed\nconfidence bands, excluding in full generality pathologies as empty confidence\nregions or unstable solutions. The method is completely general and directly\napplicable to all problems of limits.", "category": "hep-ex" }, { "text": "Measurement of the Branching Fraction Br(Lambda_c+ -> p K- pi+): We present the first model-independent measurement of the absolute branching\nfraction of the Lambda_c+ -> p K- pi+ decay using a data sample of 978 fb^-1\ncollected with the Belle detector at the KEKB asymmetric-energy e+e- collider.\nThe number of Lambda_c+ baryons is determined by reconstructing the recoiling\nD(*)- anti-p pi+ system in events of the type e+e- -> D(*)- anti-p pi+\nLambda_c+. The branching fraction is measured to be Br(Lambda_c+ -> p K- pi+) =\n(6.84 +- 0.24^{+0.21}_{-0.27})%, where the first and second uncertainties are\nstatistical and systematic, respectively.", "category": "hep-ex" }, { "text": "Search for Low Mass Higgs Boson at the Tevatron: We present the current status of searches for a low mass Standard Model Higgs\nboson (M_H below ~ 135 GeV/c^2) using data collected from ppbar collisions at\nthe Fermilab Tevatron collider at \\sqrt{s}= 1.96 TeV. A summary of the latest\nresults from the CDF and D0 collaborations is reported in this paper, focusing\nin particular on ongoing efforts to increase overall search sensitivity through\nimprovements to the analysis methods.", "category": "hep-ex" }, { "text": "Experimental study of the e+e- -> pi0 gamma process in the energy region\n sqrt(s)=0.60-0.97 GeV: Results of the study of the e+e-->pi0 gamma process with SND detector at\nVEPP-2M collider in the c.m.s. energy range sqrt(s)=0.60-0.97 GeV are\npresented. Using 36513 selected events corresponding to a total integrated\nluminosity of 3.4 pb^-1 the e+e-->pi0 gamma cross section was measured. The\nenergy dependence of the cross section was analyzed in the framework of the\nvector meson dominance model. The data are well described by a sum of\nphi,omega,rho0->pi0 gamma decay contributions with measured decay\nprobabilities: Br(omega->pi0 gamma)=(9.34+-0.15+-0.31)% and Br(rho0->pi0\ngamma)=(5.15+-1.16+-0.73)*10^-4 . The rho-omega relative interference phase is\nphi(rho,omega}=(-10.2+-6.5+-2.5) degree.", "category": "hep-ex" }, { "text": "Amplitude Analysis and Branching Fraction Measurement of $D^0\\rightarrow\n K^-\u03c0^+\u03c0^0\u03c0^0$: Utilizing the dataset corresponding to an integrated luminosity of $2.93$\nfb$^{-1}$ at $\\sqrt{s}=3.773$ GeV collected by the BESIII detector, we report\nthe first amplitude analysis and branching fraction measurement of the\n$D^0\\rightarrow K^-\\pi^+\\pi^0\\pi^0$ decay. We investigate the sub-structures\nand determine the relative fractions and the phases among the different\nintermediate processes. Our results are used to provide an accurate detection\nefficiency and allow measurement of ${\\cal B}(D^0\\rightarrow\nK^-\\pi^+\\pi^0\\pi^0) \\,=\\, (8.86 \\pm 0.13(\\text{stat}) \\pm\n0.19(\\text{syst}))\\%$.", "category": "hep-ex" }, { "text": "Determination of electron-nucleus collision geometry with forward\n neutrons: There are a large number of physics programs one can explore in\nelectron-nucleus collisions at a future electron-ion collider. Collision\ngeometry is very important in these studies, while the measurement for an\nevent-by-event geometric control is rarely discussed in the prior deep\ninelastic scattering experiments off a nucleus. This paper seeks to provide\nsome detailed studies on the potential of tagging collision geometries through\nforward neutron multiplicity measurements with a zero degree calorimeter. This\ntype of geometry handle, if achieved, can be extremely beneficial in\nconstraining nuclear effects for the electron-nucleus program at an\nelectron-ion collider.", "category": "hep-ex" }, { "text": "Measurements of charm lifetimes at Belle II: We report on absolute lifetime measurements of charmed hadrons using the data\ncollected by the Belle II experiment between 2019 and 2021. The measured\nlifetimes of $D^0$, $D^+$, and $\\Lambda_c^+$ are the most precise to date and\nconsistent with previous measurements. Our result indicates that $\\Omega_c^0$\nis not the shortest-living singly charmed baryon.", "category": "hep-ex" }, { "text": "Measurements of the top-quark mass using charged particle tracking: We present three measurements of the top-quark mass in the lepton plus jets\nchannel with approximately 1.9 fb-1 of integrated luminosity collected with the\nCDF II detector using quantities with minimal dependence on the jet energy\nscale. One measurement exploits the transverse decay length of b-tagged jets to\ndetermine a top-quark mass of 166.9+9.5-8.5 (stat) +/- 2.9 (syst) GeV/c2, and\nanother the transverse momentum of electrons and muons from W-boson decays to\ndetermine a top-quark mass of 173.5+8.8-8.9 (stat) +/- 3.8 (syst) GeV/c2. These\nquantities are combined in a third, simultaneous mass measurement to determine\na top-quark mass of 170.7 +/- 6.3 (stat) +/- 2.6 (syst) GeV/c2.", "category": "hep-ex" }, { "text": "Search for new physics in dijet angular distributions using\n proton-proton collisions at $\\sqrt{s}=$ 13 TeV and constraints on dark matter\n and other models: A search is presented for physics beyond the standard model, based on\nmeasurements of dijet angular distributions in proton-proton collisions at\n$\\sqrt{s}=$ 13 TeV. The data collected with the CMS detector at the LHC\ncorrespond to an integrated luminosity of 35.9 fb$^{-1}$. The observed\ndistributions are found to be in agreement with predictions from perturbative\nquantum chromodynamics that include electroweak corrections. Constraints are\nplaced on models containing quark contact interactions, extra spatial\ndimensions, quantum black holes, or dark matter using the detector-level\ndistributions. In a benchmark model where only left-handed quarks participate,\ncontact interactions are excluded at the 95% confidence level up to a scale of\n12.8 or 17.5 TeV, for destructive or constructive interference, respectively.\nThe most stringent lower limits to date are set on the ultraviolet cutoff in\nthe Arkani-Hamed-Dimopoulos-Dvali model of extra dimensions. In the\nGiudice-Rattazzi-Wells convention, the cutoff scale is excluded up to 10.1 TeV.\nThe production of quantum black holes is excluded for masses below 5.9 and 8.2\nTeV, depending on the model. For the first time, lower limits between 2.0 and\n4.6 TeV are set on the mass of a dark matter mediator for (axial-)vector\nmediators, for the universal quark coupling $g_\\mathrm{q}\\geq$ 1.", "category": "hep-ex" }, { "text": "Measurement of the cross-section ratio\n $\u03c3(\u03c7_{c2})/\u03c3(\u03c7_{c1})$ for prompt $\u03c7_c$ production at\n $\\sqrt{s}=7$ TeV: The prompt production of the charmonium $\\chi_{c1}$ and $\\chi_{c2}$ mesons\nhas been studied in proton-proton collisions at the Large Hadron Collider at a\ncentre-of-mass energy of $\\sqrt{s}=7$ TeV. The $\\chi_c$ mesons are identified\nthrough their decays $\\chi_c\\to J/\\psi\\,\\gamma$ with $J/\\psi \\to \\mu^+ \\mu^-$\nusing 36 $\\mathrm{pb^{-1}}$ of data collected by the LHCb detector in 2010. The\nratio of the prompt production cross-sections for the two $\\chi_c$ spin states,\n$\\sigma(\\chi_{c2})/\\sigma(\\chi_{c1})$, has been determined as a function of the\n$J/\\psi$ transverse momentum, $p_{\\mathrm{T}}^{J/\\psi}$, in the range from 2 to\n15 GeV/$c$. The results are in agreement with the next-to-leading order\nnon-relativistic QCD model at high $p_{\\mathrm{T}}^{J/\\psi}$ and lie\nconsistently above the pure leading-order colour singlet prediction.", "category": "hep-ex" }, { "text": "A Measurement of the K0 Charge Radius and a CP Violating Asymmetry\n Together with a Search for CP Violating E1 Direct Photon Emission in the Rare\n Decay KL->pi+pi-e+e-: Using the complete KTeV data set of 5241 candidate KL->pi+pi-e+e- decays\n(including an estimated background of 204+-14 events), we have measured the\ncoupling gCR=0.163+- 0.014(stat)+-0.023(syst) of the CP conserving charge\nradius process and from it determined a K0 charge radius of\n(K0)=(-0.077+-0.007(stat)+-0.011(syst)) fm**2. We have also determined a\nfirst experimental upper limit of 0.04 (90% CL) for the ratio |g_{E1}|/|g_{M1}|\nof the coupling for the E1 direct photon emission process relative to the\ncoupling for M1 direct photon emission process. We also report the measurement\nof its associated vector form factor |gM1`|(1+\n(a_1/a_2)/(M(rho)**2-M(K)**2)+2M(K)E(gamma*)) where |gM1`|=(1.11+-\n0.12(stat)+-0.08(syst) and a_1/a_2 = (-0.744+-0.027(stat)0.032(syst))\nGeV**2/c**2. In addition, a measurement of the manifestly CP violating\nasymmetry of magnitude (13.6+- 1.4+-(stat)+-1.5(syst))% in the CP and T odd\nangle phi between the decay planes of the e+e- and pi+pi- pairs in the KL\ncenter of mass system is reported.", "category": "hep-ex" }, { "text": "photon+jet event rate estimation for the gluon distribution\n determination at the Tevatron Run II: Since a lot of theoretical predictions on the production of new particles\n(Higgs, SUSY) at the Tevatron are based on model estimations of the proton\ngluon density behavior at low $x$ and high values of a transfered momentum Q^2,\nthe study of a possibility of a measurement of the gluon density in this\nkinematic region directly in Tevatron experiments is obviously of a big\ninterest [1].\n Basing on the selection criteria proposed ealier in [1,2], the background\nevents suppression factors and corresponding signal events selection\nefficiencies are determined here. The estimation of the number of photon+jet\nevents suitable for measurement of gluon distribution in different x and Q^2\nintervals at Tevatron Run II is also done.\n It is shown that with integrated luminosity L_{int}=3 fb^-1 it would be\npossible to collect about one million of these events. This number would allow\nto cover a new kinematical region, 10^-3 < x < 1.0 with 1.6*10^3 < Q^2 < 2*10^4\n(GeV/c)^2, not studied in any previous experiment. This area includes the\nvalues of Q^2 that are, on the average, by about one order of magnitude higher\nthan those reached at HERA now. The rates of g c-> photon + jet events are also\nobtained.", "category": "hep-ex" }, { "text": "Studies of $X(3872)$ and $\u03c8(2S)$ production in $p\\bar{p}$ collisions\n at 1.96 TeV: We present various properties of the production of the $X(3872)$ and\n$\\psi(2S)$ states based on 10.4 fb$^{-1}$ collected by D0 experiment in\nTevatron $p \\bar p$ collisions at $\\sqrt{s}$ = 1.96 TeV. For both states, we\nmeasure the nonprompt fraction $f_{NP}$ of the inclusive production rate due to\ndecays of $b$-flavored hadrons. We find the $f_{NP}$ values systematically\nbelow those obtained at the LHC. The $f_{NP}$ fraction for $\\psi(2S)$ increases\nwith transverse momentum whereas for the X(3872) it is constant within large\nuncertainties, in agreement with the LHC results. The ratio of prompt to\nnonprompt $\\psi(2S)$ production, $(1 - f_{NP}) / f_{NP}$, decreases only\nslightly going from the Tevatron to the LHC, but for the $X(3872)$ this ratio\ndecreases by a factor of about 3. We test the soft-pion signature of the\n$X(3872)$ modeled as a weakly-bound charm-meson pair by studying the production\nof the $X(3872)$ as a function of the kinetic energy of the $X(3872)$ and the\npion in the $X(3872)\\pi$ center-of-mass frame. For a subsample consistent with\nprompt production, the results are incompatible with a strong enhancement in\nthe production of the $X(3872)$ at small kinetic energy of the $X(3872)$ and\nthe $\\pi$ in the $X(3872)\\pi$ center-of-mass frame expected for the\n$X$+soft-pion production mechanism. For events consistent with being due to\ndecays of $b$ hadrons, there is no significant evidence for the soft-pion\neffect but its presence at the level expected for the binding energy of 0.17\nMeV and the momentum scale $\\Lambda=M(\\pi)$ is not ruled out.", "category": "hep-ex" }, { "text": "Top-quark mass at hadron colliders: Top quarks can be produced abundantly at hadron colliders like the Tevatron\nat Fermilab and the Large Hadron Collider at CERN, and a variety of\nmeasurements of top-quark properties have been gathered in the recent years\nfrom four experiments: CDF and D0 at the Tevatron and ATLAS and CMS at the\nLarge Hadron Collider. In this review the most recent results on the\nmeasurement of the top-quark mass by the four different collaborations, with\nvarious techniques and considering different topologies, are reported.", "category": "hep-ex" }, { "text": "Measurements of jet-related observables at the LHC: During the first years of the LHC operation a large amount of jet data was\nrecorded by the ATLAS and CMS experiments. In this review several measurements\nof jet-related observables are presented, such as multi-jet rates and cross\nsections, ratios of jet cross sections, jet shapes and event shape observables.\nAll results presented here are based on jet data collected at a center-of-mass\nenergy of 7 TeV. Data are compared to various Monte Carlo generators, as well\nas to theoretical next-to-leading-order calculations allowing a test of\nperturbative Quantum Chromodynamics in a previously unexplored energy region.", "category": "hep-ex" }, { "text": "Nucleon Electromagnetic Form Factors in the Timelike Region: The electromagnetic form factors of the proton and the neutron in the\ntimelike region are reviewed. In view of the forthcoming experimental projects\ndevoted to investigate these observables, we present the current status of the\nfield and we emphasize the relevant role, that accurate measurements, refined\nphenomenological analyses, as well as microscopic models will play with the\ngoal of achieving deeper insights into the structure of the nucleon and its\ninner dynamics.", "category": "hep-ex" }, { "text": "Recent structure function results from neutrino scattering at Fermilab: We report on the extraction of the structure functions F_2 and Delta xF_3 =\nxF_3(nu)-xF_3(nubar) from CCFR nu_mu-Fe and nubar_mu-Fe different ial cross\nsections. The extraction is performed in a physics model independent (PMI) way.\nThis first measurement of Delta xF_3, which is useful in testing models of\nheavy charm production, is higher than current theoretical predictios. The\nratio of the F_2 (PMI) values measured in nu_mu and mu scattering is in\nagreement (within 5%) with the NLO predictions using massive charm production\nschemes, thus resolving the long-standing discrepancy between the two sets of\ndata. In addition, measurements of F_L (or, equivalently, R) and 2xF_1 are\nreported in the kinematic region where anomalous nuclear effects in R are\nobserved at HERMES.", "category": "hep-ex" }, { "text": "Recent Results on Light-Meson Spectroscopy from COMPASS: The main goal of the spectroscopy program at COMPASS is to explore the\nlight-meson spectrum below about $2\\,\\text{GeV}/c^2$ in diffractive production.\nOur flagship channel is the decay into three charged pions: $p + \\pi^-\\to\n\\pi^-\\pi^-\\pi^+ + p_\\text{recoil}$, for which COMPASS has acquired the so far\nworld's largest dataset of roughly $50\\,\\text{M}$ exclusive events using an\n$190\\,\\text{GeV}/c$ $\\pi^-$ beam. Based on this dataset, we performed an\nextensive partial-wave analysis. In order to extract the resonance parameters\nof the $\\pi_J$ and $a_J$ states that appear in the $\\pi^-\\pi^-\\pi^+$ system, we\nperformed the so far largest resonance-model fit, using Breit-Wigner resonances\nand non-resonant contributions.\n This method in combination with the high statistical precision of our\nmeasurement allows us to study ground and excited states. We have found an\nevidence of the $a_1(1640)$ and $a_2(1700)$ in our data, which are the first\nexcitations of the $a_1(1260)$ and $a_2(1320)$, respectively. The relative\nstrength of the excited states with respect to the corresponding ground state\nis larger in the $f_2(1270)\\,\\pi$ decay mode compared to the $\\rho(770)\\,\\pi$\ndecay mode. We also study the spectrum of $\\pi_2$ states in our data.\nTherefore, we simultaneously describe four $J^{PC}=2^{-+}$ waves in the\nresonance-model fit by using three $\\pi_2$ resonances, the $\\pi_2(1670)$, the\n$\\pi_2(1880)$, and the $\\pi_2(2005)$. Within the limits of our model, we can\nconclude that the $\\pi_2(2005)$ is required to describe all four $2^{-+}$ waves\nproperly.", "category": "hep-ex" }, { "text": "Interpretation of Scalar and axial mesons in LHCb from an historical\n perspective: LHCb measurements of $B_{d,s} \\to J/\\psi + X$ are shown to be consistent with\nhistorical data on scalar and axial mesons below 2 GeV. This is in contrast to\nsome recent interpretations of these data. Further tests of our hypotheses in\nother $B_{u,d,s} \\to J/\\psi + X$ decay modes are suggested.", "category": "hep-ex" }, { "text": "Search for Factorization-Suppressed B -> chi_c K(*) Decays: We search for the factorization-suppressed decays B -> chi_c0 K(*) and B ->\nchi_c2 K(*), with chi_c0 and chi_c2 decaying into J/psi gamma using a sample of\n124 10^6 BBbar events collected with the BABAR detector at the PEP-II storage\nring of the Stanford Linear Accelerator Center.", "category": "hep-ex" }, { "text": "Study of Top-quark Production and Decay Vertices with LCD Fast\n Simulation: We report a study of top-quark reconstruction in $e^+e^- \\rightarrow\nt\\bar{t}$ events at a 500 GeV linear collider using the LCD Fast simulator. The\ninitial study of top-quark anomalous couplings is also reported. The final\nstates of 4 jets and lepton as well as 6 jets are used. Using the 4 jets and\nlepton final state, we estimate the preliminary sensitivities for form factors\nat the $\\gamma/Z^0 t\\bar{t}$ vertex. In the 6 jets reconstruction, we show\nabilities of the top-quark charge identification and the $c$-quark tagging in W\ndecays.", "category": "hep-ex" }, { "text": "Evaluation of the LEP Centre-of-Mass Energy Above the W-Pair Production\n Threshold: Knowledge of the centre-of-mass energy at LEP2 is of primary importance to\nset the absolute energy scale for the measurement of the W-boson mass. The beam\nenergy above 80 GeV is derived from continuous measurements of the magnetic\nbending field by 16 NMR probes situated in a number of the LEP dipoles. The\nrelationship between the fields measured by the probes and the beam energy is\ncalibrated against precise measurements of the average beam energy between 41\nand 55 GeV made using the resonant depolarisation technique. The linearity of\nthe relationship is tested by comparing the fields measured by the probes with\nthe total bending field measured by a flux loop. This test results in the\nlargest contribution to the systematic uncertainty. Several further corrections\nare applied to derive the the centre-of-mass energies at each interaction\npoint. In addition the centre-of-mass energy spread is evaluated. The beam\nenergy has been determined with a precision of 25 MeV for the data taken in\n1997, corresponding to a relative precision of 2.7x10^{-4}. This is small in\ncomparison to the present uncertainty on the W mass measurement at LEP.\nHowever, the ultimate statistical precision on the W mass with the full LEP2\ndata sample should be around 25 MeV, and a smaller uncertainty on the beam\nenergy is desirable. Prospects for improvements are outlined.", "category": "hep-ex" }, { "text": "Global search for new physics at CDF: A model-independent global search for new physics has been performed at the\nCDF experiment. This search examines 399 final states, looking for\ndiscrepancies between observation and the standard model expectation in\npopulations, kinematic shapes, bumps in mass distributions suggestive of new\nresonances and the tails of the summed transverse momentum distribution. This\nglobal search reveals no evidence of physics beyond the Standard Model in 2.0\nfb^-1 of p-pbar collisions at sqrt(s)=1.96 TeV.", "category": "hep-ex" }, { "text": "Evidence for the associated production of the Higgs boson and a top\n quark pair with the ATLAS detector: A search for the associated production of the Higgs boson with a top quark\npair ($t\\bar t H$) is reported. The search is performed in multilepton final\nstates using a dataset corresponding to an integrated luminosity of 36.1\nfb$^{-1}$ of proton--proton collision data recorded by the ATLAS experiment at\na center-of-mass energy $\\sqrt{s} = 13$ TeV at the Large Hadron Collider. Higgs\nboson decays to $WW^*$, $\\tau\\tau$, and $ZZ^*$ are targeted. Seven final\nstates, categorized by the number and flavor of charged-lepton candidates, are\nexamined for the presence of the Standard Model Higgs boson with a mass of 125\nGeV and a pair of top quarks. An excess of events over the expected background\nfrom Standard Model processes is found with an observed significance of 4.1\nstandard deviations, compared to an expectation of 2.8 standard deviations. The\nbest fit for the $t\\bar t H$ production cross section is $\\sigma(t\\bar t H) =\n790^{+230}_{-210}$ fb, in agreement with the Standard Model prediction of\n$507^{+35}_{-50}$ fb. The combination of this result with other $t\\bar t H$\nsearches from the ATLAS experiment using the Higgs boson decay modes to $b\\bar\nb$, $\\gamma\\gamma$ and $ZZ^* \\to 4\\ell$, has an observed significance of 4.2\nstandard deviations, compared to an expectation of 3.8 standard deviations.\nThis provides evidence for the $t\\bar t H$ production mode.", "category": "hep-ex" }, { "text": "Measurement of CP-violating asymmetries in B^0 -> (rho pi)^0 decays\n using a time-dependent Dalitz plot analysis: We present results for a time-dependent Dalitz plot measurement of\nCP-violating asymmetries in the mode B^0 -> pi^+ pi^- pi^0. The dataset is\nderived from the complete sample of 471 x 10^6 BBbar meson pairs collected with\nthe BABAR detector at the PEP-II asymmetric-energy e^+e^- collider at the SLAC\nNational Accelerator Laboratory operating on the Upsilon(4S) resonance. We\nextract parameters describing the time-dependent B^0 -> rho pi decay\nprobabilities and CP asymmetries, including C = 0.016\\pm0.059\\pm0.036, DeltaC =\n0.234\\pm0.061\\pm0.048, S = 0.053\\pm0.081\\pm0.034, and DeltaS =\n0.054\\pm0.082\\pm0.039, where the uncertainties are statistical and systematic,\nrespectively. We perform a two-dimensional likelihood scan of the direct\nCP-violation asymmetry parameters for B^0 -> rho^\\pm pi^\\mp decays, finding the\nchange in chi^2 between the minimum and the origin (corresponding to no direct\nCP violation) to be Delta(chi^2)=6.42. We present information on the\nCP-violating parameter alpha in a likelihood scan that incorporates B^\\pm ->\nrho pi measurements.", "category": "hep-ex" }, { "text": "Measurements of differential cross sections of Z/gamma*+jets+X events in\n proton anti-proton collisions at sqrt{s}=1.96 TeV: We present cross section measurements for Z/gamma*+jets+X production,\ndifferential in the transverse momenta of the three leading jets. The data\nsample was collected with the D0 detector at the Fermilab Tevatron proton\nanti-proton collider at a center-of-mass energy of 1.96 TeV and corresponds to\nan integrated luminosity of 1 fb-1. Leading and next-to-leading order\nperturbative QCD predictions are compared with the measurements, and agreement\nis found within the theoretical and experimental uncertainties. We also make\ncomparisons with the predictions of four event generators. Two\nparton-shower-based generators show significant shape and normalization\ndifferences with respect to the data. In contrast, two generators combining\ntree-level matrix elements with a parton shower give a reasonable description\nof the the shapes observed in data, but the predicted normalizations show\nsignificant differences with respect to the data, reflecting large scale\nuncertainties. For specific choices of scales, the normalizations for either\ngenerator can be made to agree with the measurements.", "category": "hep-ex" }, { "text": "Search for Standard Model Higgs in WH->lvbb at the Tevatron: We present a search for the Standard Model Higgs boson produced in\nassociation with a W boson in $p\\bar{p}$ collisions at a center-of-mass energy\nof $\\sqrt{s} = 1.96$ TeV. The search is performed in the $WH\\to \\ell\\nu\nb\\bar{b}$ channel using 2.7 fb$^{-1}$ of data collected by both the CDF\ndetector and by the $D\\O$ detector, at the Fermilab Tevatron. The searches\nemploy artificial neural network, matrix element and boosted decision tree\ntechniques to improve the separation between signal and background. Additional\ntechniques used to improve the Higgs sensitivity include the use of optimized\nb-quark jet energy corrections and improved algorithms for identifying\nb-quarks. In the absence of an observed excess in data, upper limits are set by\nboth experiments on the Higgs production rate times branching ratio for a range\nof possible Higgs masses between 100 and 150 GeV.", "category": "hep-ex" }, { "text": "A search for flavor-changing non-standard neutrino interactions by MINOS: We report new constraints on flavor-changing non-standard neutrino\ninteractions (NSI) using data from the MINOS experiment. We analyzed a combined\nset of beam neutrino and antineutrino data, and found no evidence for\ndeviations from standard neutrino mixing. The observed energy spectra constrain\nthe NSI parameter to the range $-0.20 < \\varepsilon_{\\mu\\tau} <\n0.07\\;\\text{(90% C.L.)}$", "category": "hep-ex" }, { "text": "Observation of $D^+\\to\u03b7\u03b7\u03c0^+$ and improved measurement of\n $D^{0(+)}\\to\u03b7\u03c0^+\u03c0^{-(0)}$: Using an $e^+e^-$ annihilation data sample corresponding to an integrated\nluminosity of $2.93\\,\\rm fb^{-1}$ collected at the center-of-mass energy of\n3.773\\,GeV with the BESIII detector, we measure the absolute branching\nfractions of $D^+\\to\\eta\\eta\\pi^+$, $D^+\\to\\eta\\pi^+\\pi^0$, and\n$D^0\\to\\eta\\pi^+\\pi^-$ to be $(2.96 \\pm 0.24 \\pm 0.13)\\times 10^{-3}$, $(2.23\n\\pm 0.15 \\pm 0.11)\\times 10^{-3}$, and $(1.20 \\pm 0.07 \\pm 0.04)\\times\n10^{-3}$, respectively, where the first uncertainties are statistical and the\nsecond ones systematic. The $D^+\\to\\eta\\eta\\pi^+$ decay is observed for the\nfirst time and the branching fractions of $D^{+(0)}\\to\\eta\\pi^+\\pi^{0(-)}$ are\nmeasured with much improved precision. In addition we test for $CP$ asymmetries\nin the separated charge-conjugate branching fractions; no evidence of $CP$\nviolation is found.", "category": "hep-ex" }, { "text": "Search for the charged lepton flavor violating decay $J/\u03c8\\to e\u03c4$: A search for the charged lepton flavor violating decay $J/\\psi\\to\ne^{\\pm}\\tau^{\\mp}$ with $\\tau^{\\mp} \\to \\pi^{\\mp}\\pi^0\\nu_{\\tau}$ is performed\nwith about $10$ billion $J/ \\psi$ events collected with the BESIII detector at\nthe BEPCII. No significant signal is observed, and an upper limit is set on the\nbranching fraction $\\mathcal{B}(J/\\psi\\to e^{\\pm}\\tau^{\\mp})<7.5\\times10^{-8}$\nat the 90$\\%$ confidence level. This improves the previously published limit by\ntwo orders of magnitude.", "category": "hep-ex" }, { "text": "High momentum particle and jet production in photon-photon collisions: Jet and particle production have been studied in collisions of quasi-real\nphotons collected during the LEP2 program. OPAL and DELPHI report good\nagreement of NLO perturbative QCD with the measured differential di-jet cross\nsections, which reach a mean transverse energy of the di-jet system of 25 GeV.\nL3, on the other hand, finds drastic disagreement of the same calculation with\nsingle jet production for transverse jet momenta larger than about 25 GeV. L3\nobserves similar disagreement between data and NLO QCD in their measurements of\ncharged and neutral particle production at high transverse momenta of the\nparticles. A recent measurement performed by DELPHI of the same quantities does\nnot confirm this observation.", "category": "hep-ex" }, { "text": "Double Helicity Asymmetries of Forward Neutral Pions from $\\sqrt{s}=510$\n GeV $pp$ Collisions at STAR: Longitudinally polarized $p+p$ scattering experiments provide access to gluon\npolarization via measurement of the double helicity asymmetry, $A_{LL}$. At the\ncompletion of the 2013 RHIC running period, a significant dataset of $\\pi^{0}$s\ncorresponding to an integrated luminosity of 46 $\\text{pb}^{-1}$ (2012) and 8\n$\\text{pb}^{-1}$ (2013) produced from polarized $p+p$ scattering at\n$\\sqrt{s}=510$ GeV with an average beam polarization of approximately $50\\%$\nwas acquired. The $\\pi^{0}$ kinematics were measured via isolation cones by the\nSTAR Forward Meson Spectrometer, an electromagnetic calorimeter covering a\nforward pseudorapidity range of $2.6 < \\eta <4$. The asymmetric $qg \\to qg$\nsubprocess becomes more dominant in this forward region than in the midrapidity\nregion; furthermore, asymmetry measurements in the forward region are sensitive\nto low-$x$ gluons. Progress on $A_{LL}$ determined from forward $\\pi^{0}$\nevents, complementing previous midrapidity measurements, are presented.", "category": "hep-ex" }, { "text": "Study of di-pion bottomonium transitions and search for the h_b(1P)\n state: We study inclusive di-pion decays using a sample of 108 x 10^6 Upsilon(3S)\nevents recorded with the BABAR detector. We search for the decay mode\nUpsilon(3S) --> pi+ pi- h_b(1P) and find no evidence for the bottomonium\nspin-singlet state h_b(1P) in the invariant mass distribution recoiling against\nthe pi+ pi- system. Assuming the h_b(1P) mass to be 9.900 GeV/c^2, we measure\nthe upper limit on the branching fraction B[Upsilon(3S) --> pi+ pi- h_b(1P)] <\n1.2 x 10^{-4}, at 90% confidence level. We also investigate the chi_{bJ}(2P)\n--> pi+ pi- chi_{bJ}(1P), Upsilon(3S) --> pi+ pi- Upsilon(2S), and Upsilon(2S)\n--> pi+ pi- Upsilon(1S) di-pion transitions and present an improved measurement\nof the branching fraction of the Upsilon(3S) --> pi+ pi- Upsilon(2S) decay and\nof the Upsilon(3S)-Upsilon(2S) mass difference.", "category": "hep-ex" }, { "text": "Measuring the tau polarization at ILC: Measurement of the tau lepton polarization in \\eett\\ is an important\nelectro-weak measurement at ILC and other future electron-positron colliders.\nIn this paper we discuss several methods to extract polarimeter information for\n\\eett\\ events at the nominal centre-of-mass energy, and develop a new method,\nbased on charged particle impact parameter measurement, which can accurately\nreconstruct tau momenta even in events with significant Initial State\nRadiation.\n In future work we will extend the study to estimate the precision with which\nthe tau polarization can be measured at ILC-250, both for high-mass tau pairs\nand for those which radiatively return to the $Z^0$ peak. This will complement\nour past study which showed that the tau polarization can be measured to better\nthan 1\\% at the ILC-500.", "category": "hep-ex" }, { "text": "Review on reactor neutrino present and future: Nuclear reactors are an essential source of neutrinos. In this proceeding, I\nreview the past and current status of the research on neutrino oscillations\nusing reactor neutrinos. I also present a promising idea for positron tagging\nthat will potentially be a game-changer in the field.", "category": "hep-ex" }, { "text": "Heavy Flavour Physics at HERA: New results with increased statistics are presented for heavy flavour\nproduction at Q2<150 Gev2 and in the photoproduction limit Q2-->0. Cross\nsections for Dstar production, F2charm, the gluon density in the proton, and\ninelastic J/psi production are discussed and compared to theoretical\ncalculations. A first measurement of the b anti-b cross section is reported.", "category": "hep-ex" }, { "text": "Time-Integrated Luminosity Recorded by the BABAR Detector at the PEP-II\n e+e- Collider: We describe a measurement of the time-integrated luminosity of the data\ncollected by the BABAR experiment at the PEP-II asymmetric-energy e+e- collider\nat the Upsilon(4S), Upsilon(3S) and Upsilon(2S) resonances and in a continuum\nregion below each resonance. We measure the time-integrated luminosity by\ncounting e+e- --> e+e- and (for the Upsilon(4S) only) e+e- --> mu+mu- candidate\nevents, allowing additional photons in the final state. We use data-corrected\nsimulation to determine the cross sections and reconstruction efficiencies for\nthese processes, as well as the major backgrounds. Due to the large cross\nsections of e+e- --> e+e- and e+e- --> mu+mu-, the statistical uncertainties of\nthe measurement are substantially smaller than the systematic uncertainties.\nThe dominant systematic uncertainties are due to observed differences between\ndata and simulation, as well as uncertainties on the cross sections. For data\ncollected on the Upsilon(3S) and Upsilon(2S) resonances, an additional\nuncertainty arises due to Upsilon --> e+e-X background. For data collected off\nthe Upsilon resonances, we estimate an additional uncertainty due to\ntime-dependent efficiency variations, which can affect the short off-resonance\nruns. The relative uncertainties on the luminosities of the on-resonance\n(off-resonance) samples are 0.43% (0.43%) for the Upsilon(4S), 0.58% (0.72%)\nfor the Upsilon(3S), and 0.68% (0.88%) for the Upsilon(2S).", "category": "hep-ex" }, { "text": "Introduction to HOBIT, a b-Jet Identification Tagger at the CDF\n Experiment Optimized for Light Higgs Boson Searches: We present the development and validation of the Higgs Optimized b\nIdentification Tagger (HOBIT), a multivariate b-jet identification algorithm\noptimized for Higgs boson searches at the CDF experiment at the Fermilab\nTevatron. At collider experiments, b taggers allow one to distinguish particle\njets containing B hadrons from other jets; these algorithms have been used for\nmany years with great success at CDF. HOBIT has been designed specifically for\nuse in searches for light Higgs bosons decaying via H ! b\\bar{b}. This fact\ncombined with the extent to which HOBIT synthesizes and extends the best ideas\nof previous taggers makes HOBIT unique among CDF b-tagging algorithms.\nEmploying feed-forward neural network architectures, HOBIT provides an output\nvalue ranging from approximately -1 (\"light-jet like\") to 1 (\"b-jet like\");\nthis continuous output value has been tuned to provide maximum sensitivity in\nlight Higgs boson search analyses. When tuned to the equivalent light jet\nrejection rate, HOBIT tags 54% of b jets in simulated 120 GeV/c2 Higgs boson\nevents compared to 39% for SecVtx, the most commonly used b tagger at CDF. We\npresent features of the tagger as well as its characterization in the form of\nb-jet finding efficiencies and false (light-jet) tag rates.", "category": "hep-ex" }, { "text": "Measurement of top quark pair production in association with a Z boson\n in proton-proton collisions at $\\sqrt{s} =$ 13 TeV: A measurement of the inclusive cross section of top quark pair production in\nassociation with a Z boson using proton-proton collisions at a center-of-mass\nenergy of 13 TeV at the LHC is performed. The data sample corresponds to an\nintegrated luminosity of 77.5 fb$^{-1}$, collected by the CMS experiment during\n2016 and 2017. The measurement is performed using final states containing three\nor four charged leptons (electrons or muons), and the Z boson is detected\nthrough its decay to an oppositely charged lepton pair. The production cross\nsection is measured to be $\\sigma(\\mathrm{t\\bar{t}Z})$ $=$ 0.95 $\\pm$ 0.05\n(stat) $\\pm$ 0.06 (syst) pb. For the first time, differential cross sections\nare measured as functions of the transverse momentum of the Z boson and the\nangular distribution of the negatively charged lepton from the Z boson decay.\nThe most stringent direct limits to date on the anomalous couplings of the top\nquark to the Z boson are presented, including constraints on the Wilson\ncoefficients in the framework of the standard model effective field theory.", "category": "hep-ex" }, { "text": "New results from VES: The results of the patial wave analysis(PWA) of the pi+pi-pi- and omegapi-pi0\nsystems are presented. The a3 and a4(2040) signals are observed in the\nrho(770)pi and f2(1270)pi channels. Indications of the a1' meson existence was\nfound in the 1+0+ rhopi S-wave. The decay branching ratio of the a2(1320)- to\nomegapi-pi0 was measured. The 2+1+ wave shows a broad bump at M~1.7GeV. The\ndecays of the pi2(1670), a4(2040) and pi(1740) into omegarho- were found. The\nresonance in the b1(1235)pi wave with exotic quantum numbers jpc=1-+ at M~1.6\nis observed and the simultaneous analysis of the 1-+ wave in the b1(1235)pi,\netha'pi and rhopi final states is presented.", "category": "hep-ex" }, { "text": "Averages of $b$-hadron, $c$-hadron, and $\u03c4$-lepton properties as of\n summer 2014: This article reports world averages of measurements of $b$-hadron,\n$c$-hadron, and $\\tau$-lepton properties obtained by the Heavy Flavor Averaging\nGroup (HFAG) using results available through summer 2014. For the averaging,\ncommon input parameters used in the various analyses are adjusted (rescaled) to\ncommon values, and known correlations are taken into account. The averages\ninclude branching fractions, lifetimes, neutral meson mixing parameters, $CP$\nviolation parameters, parameters of semileptonic decays and CKM matrix\nelements.", "category": "hep-ex" }, { "text": "Angular analysis of $B^0 \\to K^\\ast(892)^0 \\ell^+ \\ell^-$: We present a measurement of angular observables, $P_4'$, $P_5'$, $P_6'$,\n$P_8'$, in the decay $B^0 \\to K^\\ast(892)^0 \\ell^+ \\ell^-$, where\n$\\ell^+\\ell^-$ is either $e^+e^-$ or $\\mu^+\\mu^-$. The analysis is performed on\na data sample corresponding to an integrated luminosity of\n$711~\\mathrm{fb}^{-1}$ containing $772\\times 10^{6}$ $B\\bar B$ pairs, collected\nat the $\\Upsilon(4S)$ resonance with the Belle detector at the\nasymmetric-energy $e^+e^-$ collider KEKB. Four angular observables,\n$P_{4,5,6,8}'$ are extracted in five bins of the invariant mass squared of the\nlepton system, $q^2$. We compare our results for $P_{4,5,6,8}'$ with Standard\nModel predictions including the $q^2$ region in which the LHCb collaboration\nreported the so-called $P_5'$ anomaly.", "category": "hep-ex" }, { "text": "Muon Decay Asymmetries from $K^0_L \\to \u03c0^0 \u03bc^+ \u03bc^-$ Decays: We have examined the decay $K^0_L \\to \\pi^0 \\mu^+ \\mu^-$ in which the\nbranching ratio, the muon energy asymmetry and the muon decay asymmetry could\nbe measured. In particular, we find that within the Standard Model the\nlongitudinal polarization ($P_L$) of the muon is proportional to the direct CP\nviolating amplitude. On the other hand the energy asymmetry and the\nout-of-plane polarization ($P_N$) depend on both indirect and direct CP\nviolating amplitudes. Although the branching ratio is small and difficult to\nmeasure because of background, the asymmetries could be large $\\cal{O}$(1) in\nthe Standard Model. A combined analysis of the energy asymmetry, $P_L$ and\n$P_N$ could be used to separate indirect CPV, direct CPV, and CP conserving\ncontributions to the decay.", "category": "hep-ex" }, { "text": "Measurement of hard double-parton interactions with the ATLAS detector: The production of W boson in association with two jets in proton-proton\ncollisions at the LHC with a centre-of-mass energy of $\\sqrt{s}$ = 7 TeV has\nbeen investigated using data collected with the ATLAS detector. The fraction of\nevents arising from double-parton scattering has been measured through the\ntransverse momentum balance between the two jets. The measurement provides new\ninformation on the scaling of the rate of double-parton scattering processes\nand constraints on proton transverse profile modeling.", "category": "hep-ex" }, { "text": "Measurements of $A_{CP}(B^0\\rightarrow K^+ \u03c0^-)$ and\n $A_{CP}(B_s\\rightarrow \u03c0^+ K^-)$ at LHCb: The LHCb experiment is designed to perform flavour physics measurements at\nthe Large Hadron Collider. Using data collected during the 2010 run, we\nreconstruct a sample of $H_b\\rightarrow h^+h'^-$ decays, where $H_b$ can be\neither a $B^0$ meson, a $B_s^0$ meson or a $\\Lambda_b$ baryon, while $h$ and\n$h^\\prime$ stand for $\\pi$, $K$ or $p$. We provide preliminary values of the\ndirect $\\mathcal{CP}$ asymmetries of the neutral $B^0$ and $B_s^0$ mesons\n$A_{CP} (B^0\\rightarrow K^+\\pi^-) = -0.074 \\pm 0.033\\mathrm{(stat.)} \\pm\n0.008\\mathrm{(syst.)}$ and $A_{CP}(B_s^0\\rightarrow\\pi^+K^-)=0.15 \\pm\n0.19\\mathrm{(stat.)} \\pm 0.02\\mathrm{(syst.)}$.", "category": "hep-ex" }, { "text": "Simulations of neutron background in a time projection chamber relevant\n to dark matter searches: Presented here are results of simulations of neutron background performed for\na time projection chamber acting as a particle dark matter detector in an\nunderground laboratory. The investigated background includes neutrons from rock\nand detector components, generated via spontaneous fission and (alpha, n)\nreactions, as well as those due to cosmic-ray muons. Neutrons were propagated\nto the sensitive volume of the detector and the nuclear recoil spectra were\ncalculated. Methods of neutron background suppression were also examined and\nlimitations to the sensitivity of a gaseous dark matter detector are discussed.\nResults indicate that neutrons should not limit sensitivity to WIMP-nucleon\ninteractions down to a level of (1 - 3) x 10^{-8} pb in a 10 kg detector.", "category": "hep-ex" }, { "text": "Planning the Future of U.S. Particle Physics (Snowmass 2013): Chapter 8:\n Instrumentation Frontier: These reports present the results of the 2013 Community Summer Study of the\nAPS Division of Particles and Fields (\"Snowmass 2013\") on the future program of\nparticle physics in the U.S. Chapter 8, on the Instrumentation Frontier,\ndiscusses the instrumentation needs of future experiments in the Energy,\nIntensity, and Cosmic Frontiers, promising new technologies for particle\nphysics research, and issues of gathering resources for long-term research in\nthis area.", "category": "hep-ex" }, { "text": "Probe of soft-QCD in minimum bias events of pp collisions with the ATLAS\n at the LHC: The study of the minimum-bias charged-particle distributions is reviewed. The\ndata are obtained using the ATLAS detector at the LHC in proton-proton\ncollisions at the centre-of-mass energies from 0.9 to13 TeV. The particles are\nrequired to have an absolute pseudorapidity less than 2.5. For charged-particle\ndistributions study two transverse momentum thresholds cases, greater than 100\nMeV and 500 MeV were taken. The charged-particle multiplicity, its dependence\non the transverse momentum and pseudorapidity, dependence of the average\ntransverse momentum on the charged-particle multiplicity and the KNO-scaling\nstudy are presented. The measured distributions are compared with the\npredictions of various tunings of Monte Carlo generator, which implement\ndifferent minimum-bias models.The Monte Carlo model predictions qualitatively\ndescribe the data well, but with some significant discrepancies. Measurements\nof minimum-bias events by the ALICE and CMS Collaborations are presented.", "category": "hep-ex" }, { "text": "Measurement of the branching fractions for Cabibbo-suppressed decays\n $D^{+}\\to K^{+} K^{-}\u03c0^{+}\u03c0^{0}$ and $D_{(s)}^{+}\\to\n K^{+}\u03c0^{-}\u03c0^{+}\u03c0^{0}$ at Belle: We present measurements of the branching fractions for the singly\nCabibbo-suppressed decays $D^+\\to K^{+}K^{-}\\pi^{+}\\pi^{0}$ and $D_s^{+}\\to\nK^{+}\\pi^{-}\\pi^{+}\\pi^{0}$, and the doubly Cabibbo-suppressed decay $D^{+}\\to\nK^{+}\\pi^{-}\\pi^{+}\\pi^{0}$, based on 980 ${\\rm fb}^{-1}$ of data recorded by\nthe Belle experiment at the KEKB $e^{+}e^{-}$ collider. We measure these modes\nrelative to the Cabibbo-favored modes $D^{+}\\to K^{-}\\pi^{+}\\pi^{+}\\pi^{0}$ and\n$D_s^{+}\\to K^{+}K^{-}\\pi^{+}\\pi^{0}$. Our results for the ratios of branching\nfractions are $B(D^{+}\\to K^{+}K^{-}\\pi^{+}\\pi^{0})/B(D^{+}\\to\nK^{-}\\pi^{+}\\pi^{+}\\pi^{0}) = (11.32 \\pm 0.13 \\pm 0.26)\\%$, $B(D^{+}\\to\nK^{+}\\pi^{-}\\pi^{+}\\pi^{0})/B(D^{+}\\to K^{-}\\pi^{+}\\pi^{+}\\pi^{0}) = (1.68 \\pm\n0.11\\pm 0.03)\\%$, and $B(D_s^{+}\\to K^{+}\\pi^{-}\\pi^{+}\\pi^{0})/B(D_s^{+}\\to\nK^{+}K^{-}\\pi^{+}\\pi^{0}) = (17.13 \\pm 0.62 \\pm 0.51)\\%$, where the\nuncertainties are statistical and systematic, respectively. The second value\ncorresponds to $(5.83\\pm 0.42)\\times\\tan^4\\theta_C$, where $\\theta_C$ is the\nCabibbo angle; this value is larger than other measured ratios of branching\nfractions for a doubly Cabibbo-suppressed charm decay to a Cabibbo-favored\ndecay. Multiplying these results by world average values for $B(D^{+}\\to\nK^{-}\\pi^{+}\\pi^{+}\\pi^{0})$ and $B(D_s^{+}\\to K^{+}K^{-}\\pi^{+}\\pi^{0})$\nyields $B(D^{+}\\to K^{+}K^{-}\\pi^{+}\\pi^{0})= (7.08\\pm 0.08\\pm 0.16\\pm\n0.20)\\times10^{-3}$, $B(D^{+}\\to K^{+}\\pi^{-}\\pi^{+}\\pi^{0})= (1.05\\pm 0.07\\pm\n0.02\\pm 0.03)\\times10^{-3}$, and $B(D_s^{+}\\to K^{+}\\pi^{-}\\pi^{+}\\pi^{0}) =\n(9.44\\pm 0.34\\pm 0.28\\pm 0.32)\\times10^{-3}$, where the third uncertainty is\ndue to the branching fraction of the normalization mode. The first two results\nare consistent with, but more precise than, the current world averages. The\nlast result is the first measurement of this branching fraction.", "category": "hep-ex" }, { "text": "Observation of WZ Production: We report the first observation of the associated production of a W boson and\na Z boson. This result is based on 1.1 fb-1 of integrated luminosity from ppbar\ncollisions at sqrt{s} = 1.96 TeV collected with the CDF II detector at the\nFermilab Tevatron. We observe 16 WZ candidates passing our event selection with\nan expected background of 2.7 +/- 0.4 events. A fit to the missing transverse\nenergy distribution indicates an excess of events compared to the background\nexpectation corresponding to a significance equivalent to six standard\ndeviations. The measured cross section is sigma(ppbar -> WZ) =\n5.0^{+1.8}_{-1.6} pb, consistent with the standard model expectation.", "category": "hep-ex" }, { "text": "Measurement of the $\\boldsymbol{W}$ Boson Production Charge Asymmetry in\n $\\boldsymbol{p\\bar{p}\\rightarrow W+X \\rightarrow e\u03bd+X}$ Events at\n $\\boldsymbol{\\sqrt{s}=1.96}$ TeV: We present a measurement of the $W$ boson production charge asymmetry in\n$p\\bar{p}\\rightarrow W+X \\rightarrow e\\nu +X$ events at a center of mass energy\nof 1.96 TeV, using 9.7 fb$^{-1}$ of integrated luminosity collected with the D0\ndetector at the Fermilab Tevatron Collider. The neutrino longitudinal momentum\nis determined using a neutrino weighting method, and the asymmetry is measured\nas a function of the $W$ boson rapidity. The measurement extends over wider\nelectron pseudorapidity region than previous results, and is the most precise\nto date, allowing for precise determination of proton parton distribution\nfunctions in global fits.", "category": "hep-ex" }, { "text": "Cross section measurement of $e^{+}e^{-} \\to K_{S}^{0}K_{L}^{0}$ at\n $\\sqrt{s}=2.00-3.08~{\\rm GeV}$: The cross sections of the process $e^{+}e^{-} \\to K_{S}^{0}K_{L}^{0}$ are\nmeasured at fifteen center-of-mass energies $\\sqrt{s}$ from $2.00$ to\n$3.08~{\\rm GeV}$ with the BESIII detector at the Beijing Electron Positron\nCollider (BEPCII). The results are found to be consistent with those obtained\nby BaBar. A resonant structure around $2.2~{\\rm GeV}$ is observed, with a mass\nand width of $2273.7 \\pm 5.7 \\pm 19.3~{\\rm MeV}/c^2$ and $86 \\pm 44 \\pm 51~{\\rm\nMeV}$, respectively, where the first uncertainties are statistical and the\nsecond ones are systematic. The product of its radiative width\n($\\Gamma_{e^+e^-}$) with its branching fraction to $K_{S}^{0}K_{L}^{0}$\n($Br_{K_{S}^{0}K_{L}^{0}}$) is $0.9 \\pm 0.6 \\pm 0.7~{\\rm eV}$.", "category": "hep-ex" }, { "text": "Simultaneous measurements of the $t\\bar{t}$, $W^+W^-$, and\n $Z/\u03b3^{*}\\rightarrow\u03c4\u03c4$ production cross-sections in $pp$\n collisions at $\\sqrt{s} = 7$ TeV with the ATLAS detector: Simultaneous measurements of the $t\\bar{t}$, $W^+W^-$, and\n$Z/\\gamma^{*}\\rightarrow\\tau\\tau$ production cross-sections using an integrated\nluminosity of $4.6\\,\\mathrm{fb}^{-1}$ of $pp$ collisions at $\\sqrt{s} =\n7\\,\\mathrm{TeV}$ collected by the ATLAS detector at the LHC are presented.\nEvents are selected with two high transverse momentum leptons consisting of an\noppositely charged electron and muon pair. The three processes are separated\nusing the distributions of the missing transverse momentum of events with zero\nand greater than zero jet multiplicities. Measurements of the fiducial\ncross-section are presented along with results that quantify for the first time\nthe underlying correlations in the predicted and measured cross-sections due to\nproton parton distribution functions. These results indicate that the\ncorrelated NLO predictions for $t\\bar{t}$ and $Z/\\gamma^{*}\\rightarrow\\tau\\tau$\nunderestimate the data, while those at NNLO generally describe the data well.\nThe full cross-sections are measured to be $\\sigma(t\\bar{t}) = 181.2 \\pm\n2.8^{+9.7}_{-9.5} \\pm 3.3 \\pm 3.3\\,\\mathrm{pb}$, $\\sigma(W^+W^-) = 53.3 \\pm\n2.7^{+7.3}_{-8.0} \\pm 1.0 \\pm 0.5\\,\\mathrm{pb}$, and\n$\\sigma(Z/\\gamma^{*}\\rightarrow\\tau\\tau) = 1174 \\pm 24^{+72}_{-87} \\pm 21 \\pm\n9\\,\\mathrm{pb}$, where the cited uncertainties are due to statistics,\nsystematic effects, luminosity and the LHC beam energy measurement,\nrespectively. The $W^+W^-$ measurement includes the small contribution from\nHiggs boson decays, $H\\rightarrow W^+W^-$.", "category": "hep-ex" }, { "text": "New Resonances and Meson Spectroscopy at BaBar and Belle: We present a short review on the recent progresses that have been made in\nmeson spectroscopy. We discuss the experimental discoveries made at the BaBar\nand Belle experiments, as well as the possible interpretations of the new\nresonances.", "category": "hep-ex" }, { "text": "Four-gap glass RPC as a candidate to a large area thin time-of-flight\n detector: A four-gap glass RPC with 0.3mm gap size was tested with hadron beam as a\ntime-of-flight detector having a time resolution of ~ 100ps. A thickness of the\ndetector together with front-end electronics is ~ 12mm. Results on time\nresolution dependently on a pad size are presented. This paper contains first\nresult on the timing RPC (with ~ 100ps resolution) having a strip read-out.\nStudy has been done within the HARP experiment (CERN-PS214) R&D work. A obtaned\ndata can be useful if a design of a large area thin timing detector has to be\ndone.", "category": "hep-ex" }, { "text": "Signal detection using biphotons and potential application in axion-like\n particle search: This paper presents a new optical system for detecting light signals\nassociated with the change in incoming photon number. The system employs\nquantum correlation of photon pairs created via spontaneous parametric\ndown-conversion (SPDC). The signal, if present, will perturb the flux of the\nincident photon stream. The perturbed photon stream is first projected through\na birefringent crystal where SPDC occurs, converting a single high-energy\nphoton into a pair of low energy photons. The photons in each pair eventually\narrive at separate detectors. By examining the biphoton correlation using the\nprobability distribution of the photons at the detectors, which varies\ndepending on the displacement of the main pump photon stream and the change in\nthe number of photons, the small optical displacement of the photon stream and\nits variance can be determined. The change in incident photon number, in other\nwords, the presence of light signal does not influence the average of the\nmeasured optical displacement values. Nevertheless, the change in optical\ndisplacement measurement variance when the number of incident photons has\nchanged detects the light signal. This optical setup enables the detection of\nlight signals with low noise and remarkably high precision and sensitivity\nusing quantum correlation. The proposed technique has potential application for\naxion-like particle search in experimental high energy physics.", "category": "hep-ex" }, { "text": "Analytical considerations for optimal axion haloscope design: The cavity haloscope provides a highly sensitive method to search for dark\nmatter axions in the microwave regime. Experimental attempts to enhance the\nsensitivity have focused on improving major aspects, such as producing strong\nmagnetic fields, increasing cavity quality factors, and achieving lowest\npossible noise temperatures. Minor details, however, also need to be carefully\nconsidered in realistic experimental designs. They are associated with\nnon-uniform magnetic fields over the detection volume, noise propagation under\nattenuation and temperature gradients, and thermal disequilibrium in the cavity\nsystem. We take analytical approaches to these topics and offer optimal\ntreatments for improved performance.", "category": "hep-ex" }, { "text": "Determination of |Vcb| using the semileptonic decay \\bar{B}^0 -->\n D^{*+}e^-\\bar\u03bd: We present a measurement of the Cabibbo-Kobayashi-Maskawa (CKM) matrix\nelement |Vcb| using a 10.2 fb^{-1} data sample recorded at the \\Upsilon(4S)\nresonance with the Belle detector at the KEKB asymmetric e^+e^- storage ring.\nBy extrapolating the differential decay width of the \\bar{B}^0 -->\nD^{*+}e^-\\bar{\\nu} decay to the kinematic limit at which the D^{*+} is at rest\nwith respect to the \\bar{B}^0, we extract the product of |Vcb| with the\nnormalization of the decay form factor F(1), |Vcb |F(1)=\n(3.54+/-0.19+/-0.18)x10^{-2}, where the first error is statistical and the\nsecond is systematic. A value of |Vcb| = (3.88+/-0.21+/-0.20+/-0.19)x10^{-2} is\nobtained using a theoretical calculation of F(1), where the third error is due\nto the theoretical uncertainty in the value of F(1). The branching fraction\nB(\\bar{B}^0 --> D^{*+}e^-\\bar{\\nu}) is measured to be\n(4.59+/-0.23+/-0.40)x10^{-2}.", "category": "hep-ex" }, { "text": "Charge Asymmetry in 1-1000 GeV Electromagnetic Showers and Possibility\n of Its Measurementnt: For the high energy electromagnetic showers the thickness dependence of a)\nthe development of electron and positron components, b) the difference between\nthe secondary electron and positron numbers, c) the charge asymmetry of high\nenergy electromagnetic showers, as well as d) the spectral distributions of the\ncomponents at the shower maxima for various energies of primary particle\nenergies,1 - 1000 GeV were investigated employing GEANT Monte Carlo simulation\npackage. Using these simulation results it is discussed the possibility of\nobservation and study of the charge asymmetry with the help of a magnetic\nspectrometer which is important for the current and future experiments on the\ndetection of radiowaves produced by high energy neutrinos.", "category": "hep-ex" }, { "text": "Search for scalar leptoquarks produced via $\u03c4$-lepton-quark\n scattering in pp collisions at $\\sqrt{s}$ = 13 TeV: The first search for scalar leptoquarks produced in $\\tau$-lepton-quark\ncollisions is presented. It is based on a set of proton-proton collision data\nrecorded with the CMS detector at the LHC at a center-of-mass energy of 13 TeV\ncorresponding to an integrated luminosity of 138 fb$^{-1}$. The reconstructed\nfinal state consists of a jet, significant missing transverse momentum, and a\n$\\tau$ lepton reconstructed through its hadronic or leptonic decays. Limits are\nset on the product of the leptoquark production cross section and branching\nfraction and interpreted as exclusions in the plane of the leptoquark mass and\nthe leptoquark-$\\tau$-quark coupling strength.", "category": "hep-ex" }, { "text": "High luminosity fixed-target experiment at the LHC: By extracting the beam with a bent crystal or by using an internal gas\ntarget, the multi-TeV proton and lead LHC beams allow one to perform the most\nenergetic fixed-target experiments ever and to study $pp$, $p$d and $p$A\ncollisions at $\\sqrt{s_{NN}}=115$ GeV and Pb$p$ and PbA collisions at\n$\\sqrt{s_{NN}}=72$ GeV with high precision and modern detection techniques.\nSuch studies would address open questions in the domain of the nucleon and\nnucleus partonic structure at high-$x$, quark-gluon plasma and, by using\nlongitudinally or transversally polarised targets, spin physics. In this paper,\nwe will review the technical solutions to obtain a high-luminosity fixed-target\nexperiment at the LHC and will discuss their possible implementations with the\nALICE and LHCb detectors.", "category": "hep-ex" }, { "text": "Snowmass 2021 Dark Matter Complementarity Report: The fundamental nature of Dark Matter is a central theme of the Snowmass 2021\nprocess, extending across all Frontiers. In the last decade, advances in\ndetector technology, analysis techniques and theoretical modeling have enabled\na new generation of experiments and searches while broadening the types of\ncandidates we can pursue. Over the next decade, there is great potential for\ndiscoveries that would transform our understanding of dark matter. In the\nfollowing, we outline a road map for discovery developed in collaboration among\nthe Frontiers. A strong portfolio of experiments that delves deep, searches\nwide, and harnesses the complementarity between techniques is key to tackling\nthis complicated problem, requiring expertise, results, and planning from all\nFrontiers of the Snowmass 2021 process.", "category": "hep-ex" }, { "text": "Determination of the QCD color factor ratio CA/CF from the scale\n dependence of multiplicity in three jet events: I examine the determination of the QCD color factor ratio CA/CF from the\nscale evolution of particle multiplicity in e+e- three jet events. I fit an\nanalytic expression for the multiplicity in three jet events to event samples\ngenerated with QCD multihadronic event generators. I demonstrate that a one\nparameter fit of CA/CF yields the expected result CA/CF=2.25 in the limit of\nasymptotically large energies if energy conservation is included in the\ncalculation. In contrast, a two parameter fit of CA/CF and a constant offset to\nthe gluon jet multiplicity, proposed in a recent study, does not yield\nCA/CF=2.25 in this limit. I apply the one parameter fit method to recently\npublished data of the DELPHI experiment at LEP and determine the effective\nvalue of CA/CF from this technique, at the finite energy of the Z0 boson, to be\n1.74+-0.03+-0.10, where the first uncertainty is statistical and the second is\nsystematic.", "category": "hep-ex" }, { "text": "Search for b--> u transitions in B- -> [K+pi-pi0]_D K-: We search for decays of a B meson into a neutral D meson and a kaon, with the\nD meson decaying into K+pi-pi0. This final state can be reached through the b\n--> c transition B- -> D0K- followed by the doubly Cabibbo-suppressed D0 -->\nK+pi-pi0, or the b --> u transition B- --> D0bar K- followed by the\nCabibbo-favored D0bar --> K+ pi-pi0. The interference of these two amplitudes\nis sensitive to the angle gamma of the unitarity triangle. We present\npreliminary results based on 226 10^{6} e+e- --> Y(4s) --> BBbar events\ncollected with the BABAR detector at SLAC. We find no significant evidence for\nthese decays and we set a limit R_ADS =(BR(B- -->[K+pi-pi0]_D K-)+ BR(B- -->\n[K-pi+pi0]_D K+))/(BR(B- -->[K-pi+pi0]_D K-)+ BR(B- --> [K+pi-pi0]_D K+))<0.039\nat 95% confidence level, which we translate with a Bayesian approach into r_B =\n|A(B- --> D0bar K-)|/|A(B- --> D0bar K-)| < 0.185 at 95% confidence level.", "category": "hep-ex" }, { "text": "Measurement of the $H \\to \u03b3\u03b3$ and $H \\to ZZ^* \\to 4 \\ell$\n cross-sections in $pp$ collisions at $\\sqrt{s}=13.6$ TeV with the ATLAS\n detector: The inclusive Higgs boson production cross-section is measured in the\ndi-photon and the $ZZ^* \\to 4 \\ell$ decay channels using 31.4 and 29.0\nfb$^{-1}$ of $pp$ collision data respectively, collected with the ATLAS\ndetector at a centre-of-mass energy of $\\sqrt{s}=13.6$ TeV. To reduce the model\ndependence, the measurement in each channel is restricted to a particle-level\nphase space that closely matches the channel's detector-level kinematic\nselection, and it is corrected for detector effects. These measured fiducial\ncross-sections are $\\sigma_{\\mathrm{fid},\\gamma \\gamma} = 76^{+14}_{-13}$ fb,\nand $\\sigma_{\\mathrm{fid},4 \\ell} = 2.80 \\pm 0.74$ fb, in agreement with the\ncorresponding Standard Model predictions of $67.6 \\pm 3.7 $ fb and $3.67 \\pm\n0.19 $ fb. Assuming Standard Model acceptances and branching fractions for the\ntwo channels, the fiducial measurements are extrapolated to the full phase\nspace yielding total cross-sections of $\\sigma(pp \\to H) = 67^{+12}_{-11}$ pb\nand $46 \\pm 12$ pb at $13.6$ TeV from the di-photon and $ZZ^* \\to 4 \\ell$\nmeasurements respectively. The two measurements are combined into a total\ncross-section measurement of $\\sigma(pp \\to H)= 58.2 \\pm 8.7$ pb, to be\ncompared with the Standard Model prediction of $\\sigma(pp \\to H)_\\mathrm{SM} =\n59.9 \\pm 2.6 $ pb.", "category": "hep-ex" }, { "text": "Form Factor Fit for e^+e^- to pi^+pi^-pi^+pi^-: The cross section of e^+e^- to pi^+pi^-pi^+pi^- has been measured by BABAR\ncollaboration. We apply the theoretical cross section deduced from the extended\nVMD (VectorMeson Dominance) model to fit these experimental data. The relevant\nparameters and the isovector form factor are obtained", "category": "hep-ex" }, { "text": "Measurements of the 125 GeV Higgs boson at CMS: Results of the measurements of the 125 GeV Higgs boson properties with\nproton-proton collision data at $\\sqrt{s}=13$ TeV collected by CMS detector are\npresented. The used Higgs boson decay channels include the five major decay\nmodes, $\\mathrm{H}\\rightarrow\\gamma\\gamma$, $\\mathrm{H}\\rightarrow{\\rm Z}{\\rm\nZ}\\rightarrow4\\ell$, $\\mathrm{H}\\rightarrow{\\rm W}{\\rm\nW}\\rightarrow\\ell\\nu\\ell\\nu$, $\\mathrm{H}\\rightarrow\\tau^{+}\\tau^{-}$ and\n$\\mathrm{H}\\rightarrow b\\bar{b}$, and two rare decay modes,\n$\\mathrm{H}\\rightarrow\\mu^{+}\\mu^{-}$ and $\\mathrm{H}\\rightarrow{\\rm\nZ}/\\gamma^{*}+\\gamma\\rightarrow\\ell\\ell\\gamma$, with $\\ell={\\rm e},\\mu$. The\nmeasured Higgs boson properties include its mass, signal strength relative to\nthe standard model prediction, signal strength modifiers for different Higgs\nboson production modes, coupling modifiers to fermions and bosons, effective\ncoupling modifiers to photons and gluons, simplified template cross sections,\nfiducial cross sections. All results are consistent, within their\nuncertainties, with the expectations for the Standard Model Higgs boson.", "category": "hep-ex" }, { "text": "A Measurement of the Proton Structure Function $F_{\\!2}(x,Q^2)$: A measurement of the proton structure function $F_{\\!2}(x,Q^2)$ is reported\nfor momentum transfer squared $Q^2$ between 4.5 $GeV^2$ and 1600 $GeV^2$ and\nfor Bjorken $x$ between $1.8\\cdot10^{-4}$ and 0.13 using data collected by the\nHERA experiment H1 in 1993. It is observed that $F_{\\!2}$ increases\nsignificantly with decreasing $x$, confirming our previous measurement made\nwith one tenth of the data available in this analysis. The $Q^2$ dependence is\napproximately logarithmic over the full kinematic range covered. The subsample\nof deep inelastic events with a large pseudo-rapidity gap in the hadronic\nenergy flow close to the proton remnant is used to measure the \"diffractive\"\ncontribution to $F_{\\!2}$.", "category": "hep-ex" }, { "text": "Search for pair production of Higgs bosons in the $b\\bar{b}b\\bar{b}$\n final state using proton--proton collisions at $\\sqrt{s} = 13$ TeV with the\n ATLAS detector: A search for Higgs-boson pair production in the $b\\bar{b}b\\bar{b}$ final\nstate is carried out with 3.2 fb$^{-1}$ of proton--proton collision data\ncollected at $\\sqrt{s} = 13$ TeV with the ATLAS detector. The data are\nconsistent with the estimated background and are used to set upper limits on\nthe production cross section of Higgs-boson pairs times branching ratio to\n$b\\bar{b}b\\bar{b}$ for both nonresonant and resonant production. In the case of\nresonant production of Kaluza--Klein gravitons within the Randall--Sundrum\nmodel, upper limits in the 24 to 91 fb range are obtained for masses between\n600 and 3000 GeV, at the 95% confidence level. The production cross section\ntimes branching ratio for nonresonant Higgs-boson pairs is also constrained to\nbe less than 1.22 pb, at the 95% confidence level.", "category": "hep-ex" }, { "text": "Results on alpha_s and QCD from (and Above) the Z0: Measurements of alpha_s from e+e- annihilation experiments are reviewed and\ncompared with measurements from other processes. Highlights are presented of\nrecent QCD studies in e+e- annihilation at the Z0 resonance.", "category": "hep-ex" }, { "text": "The $\u03c6(1020)\\to\u03c0^0\u03c0^0\u03b3$ decay: In the SND experiment at VEPP-2M $e^+e^-$ collider the\n$\\phi(1020)\\to\\pi^0\\pi^0\\gamma$ decay was studied and its branching ratio was\nmeasured: $B(\\phi\\to\\pi^0\\pi^0\\gamma)=(1.221\\pm 0.098\\pm0.061)\\cdot10^{-4}$. It\nwas shown, that $f_0(980)\\gamma$ intermediate state dominates in this decay and\nthe $f_0(980)$-meson parameters were obtained.", "category": "hep-ex" }, { "text": "\u03b1_S from LEP: Recent results on measurements of the strong coupling $\\alpha_S$ from LEP are\nreported. These include analyses of the 4-jet rate using the Durham or\nCambridge algorithm, of hadronic $Z^0$ decays with hard final state photon\nradiation, of scaling violations of the fragmentation function, of the\nlongitudinal cross section, of the $Z^0$ lineshape and of hadronic $\\tau$\nlepton decays.", "category": "hep-ex" }, { "text": "Search for an anomalous excess of charged-current $\u03bd_e$ interactions\n without pions in the final state with the MicroBooNE experiment: This article presents a measurement of $\\nu_e$ interactions without pions in\nthe final state using the MicroBooNE experiment and an investigation into the\nexcess of low-energy electromagnetic events observed by the MiniBooNE\ncollaboration. The measurement is performed in exclusive channels with\n(1$e$N$p$0$\\pi$) and without (1$e$0$p$0$\\pi$) visible final-state protons using\n6.86$\\times 10^{20}$ protons on target of data collected from the Booster\nNeutrino Beam at Fermilab. Events are reconstructed with the Pandora pattern\nrecognition toolkit and selected using additional topological information from\nthe MicroBooNE liquid argon time projection chamber. Using a goodness-of-fit\ntest the data are found to be consistent with the predicted number of events\nwith nominal flux and interaction models with a $p$-value of 0.098 in the two\nchannels combined. A model based on the low-energy excess observed in MiniBooNE\nis introduced to quantify the strength of a possible $\\nu_e$ excess. The\nanalysis suggests that if an excess is present, it is not consistent with a\nsimple scaling of the $\\nu_e$ contribution to the flux. Combined, the\n1$e$N$p$0$\\pi$ and 1$e$0$p$0$\\pi$ channels do not give a conclusive indication\nabout the tested model, but separately they both disfavor the low-energy excess\nmodel at $>$90% CL. The observation in the most sensitive 1$e$N$p$0$\\pi$\nchannel is below the prediction and consistent with no excess. In the less\nsensitive 1$e$0$p$0$\\pi$ channel the observation at low energy is above the\nprediction, while overall there is agreement over the full energy spectrum.", "category": "hep-ex" }, { "text": "Studies of Quantum-Mechanical Coherency Effects in Neutrino-Nucleus\n Elastic Scattering: Neutrino-nucleus elastic scattering ($\\nu {\\rm A}_{el}$) provides a unique\nlaboratory to study the quantum-mechanical (QM) coherency effects in\nelectroweak interactions. The deviations of the cross-sections from those of\ncompletely coherent systems can be quantitatively characterized through a\ncoherency parameter $\\alpha ( q^2 )$. The relations between $\\alpha$ and the\nunderlying nuclear physics in terms of nuclear form factors are derived. The\ndependence of cross-section on $\\alpha ( q^2 )$ for the various neutrino\nsources is presented. The $\\alpha ( q^2 )$-values are evaluated from the\nmeasured data of the COHERENT CsI and Ar experiments. Complete coherency and\ndecoherency conditions are excluded by the CsI data with $p {=} 0.004$ at $q^2\n{=} 3.1 {\\times} 10^{3} ~ {\\rm MeV^2}$ and with $p {=} 0.016$ at $q^2 {=} 2.3\n{\\times} 10^{3} ~ {\\rm MeV^2}$, respectively, verifying that both QM\nsuperpositions and nuclear many-body effects contribute to $\\nu {\\rm A}_{el}$\ninteractions.", "category": "hep-ex" }, { "text": "Measurement of charged-particle spectra in Pb+Pb collisions at\n $\\sqrt{{s}_\\mathsf{NN}} = 2.76$ TeV with the ATLAS detector at the LHC: Charged-particle spectra obtained in 0.15 nb${}^{-1}$ of Pb+Pb interactions\nat $\\sqrt{{s}_\\mathsf{{NN}}}=2.76$TeV and 4.2 pb${}^{-1}$ of pp interactions at\n$\\sqrt{s}=2.76$ TeV with the ATLAS detector at the LHC are presented in a wide\ntransverse momentum ($0.5 < p_{\\mathrm{T}} < 150$ GeV) and pseudorapidity\n($|\\eta|<2$) range. For Pb+Pb collisions, the spectra are presented as a\nfunction of collision centrality, which is determined by the response of the\nforward calorimeter located on both sides of the interaction point. The nuclear\nmodification factors $R_{\\mathrm{AA}}$ and $R_{\\mathrm{CP}}$ are presented in\ndetail as function of centrality, $p_{\\mathrm{T}}$ and $\\eta$. They show a\ndistinct $p_{\\mathrm{T}}$-dependence with a pronounced minimum at about 7 GeV.\nAbove 60 GeV, $R_{\\mathrm{AA}}$ is consistent with a plateau at a\ncentrality-dependent value, within the uncertainties. The value is\n$0.55\\pm0.01(stat.)\\pm0.04(syst.)$ in the most central collisions. The\n$R_{\\mathrm{AA}}$ distribution is consistent with flat $|\\eta|$ dependence over\nthe whole transverse momentum range in all centrality classes.", "category": "hep-ex" }, { "text": "Measurement of the polarization amplitudes and triple product\n asymmetries in the B_s^0 -> phi phi decay: Using 1.0 fb^{-1} of pp collision data collected at a centre-of-mass energy\nof sqrt{s}=7 TeV with the LHCb detector, measurements of the polarization\namplitudes, strong phase difference and triple product asymmetries in the B_s^0\n-> phi phi decay mode are presented. The measured values are |A_0|^2 = 0.365 +-\n0.022 (stat) +- 0.012 (syst), |A_perp|^2 = 0.291 +- 0.024 (stat) +- 0.010\n(syst), cos(delta_parallel) = -0.844 +- 0.068 (stat) +- 0.029 (syst), A_U =\n-0.055 +- 0.036 (stat) +- 0.018 (syst), A_V = 0.010 +- 0.036 (stat) +- 0.018\n(syst) .", "category": "hep-ex" }, { "text": "Search for High-Mass States with Lepton Plus Missing Transverse Energy\n Using the ATLAS Detector at Center-of-Mass Energy of 7 TeV: The ATLAS detector has been used to search for high-mass states decaying into\na single high momentum lepton and missing transverse energy, such as new heavy\ncharged gauge bosons. The latest search results for a W Prime boson decaying to\nlepton plus neutrino in 1.04 fb^-1 of proton-proton collisions at a center of\nmass energy of 7 TeV produced at the Large Hadron Collider are presented.", "category": "hep-ex" }, { "text": "Measurements of $t$-channel single top-quark production cross sections\n at $\\sqrt{s} = 7$ TeV with the ATLAS detector: This article presents measurements of the $t$-channel single top-quark ($t$)\nand top-antiquark ($\\bar{t}$) total production cross sections $\\sigma(tq)$ and\n$\\sigma(\\bar{t}q)$, their ratio $R_t=\\sigma(tq)/\\sigma(\\bar{t}q)$. Differential\ncross sections for the $\\sigma(tq)$ and $\\sigma(\\bar{t}q)$ processes are\nmeasured as a function of the transverse momentum and the absolute value of the\nrapidity of ($t$) and ($\\bar{t}$), respectively. The analysed data set was\nrecorded with the ATLAS detector and corresponds to an integrated luminosity of\n4.59 fb$^{-1}$. The cross sections are measured by performing a binned\nmaximum-likelihood fit to the output distributions of neural networks. The\nresulting measurements are $\\sigma(tq)=46 \\pm 6$ pb, $\\sigma(\\bar{t}q)=23 \\pm\n4$ pb, $R_t=2.04 \\pm 0.18$, consistent with the Standard Model expectation.", "category": "hep-ex" }, { "text": "Observation of B_s0->D_s*- pi+, B_s0->D_s(*)- rho+ Decays and\n Measurement of B_s0->D_s*- rho+ Polarization: First observations of the B_s0->D_s*- pi+, B_s0->D_s- rho+ and B_s0->D_s*-\nrho+ decays are reported together with measurements of their branching\nfractions: B(B_s0->D_s*- pi+)=(2.4 +0.5-0.4(stat.) +-0.3(syst.)\n+-0.4(fs))x10^(-3), B(Bs->D_s- rho+)=(8.5 +1.3-1.2(stat.) +-1.1(syst.)\n+-1.3(fs))x10^(-3) and B(Bs->D_s*- rho+)=(11.8 +2.2-2.0(stat.) +-1.7(syst.)\n+-1.8(fs))x10^(-3) (f_s=N(B_s(*)B_s(*)-bar)/N(b b-bar)). From helicity-angle\ndistributions, we measured the longitudinal polarization fraction in\nB_s0->D_s*- rho+ decays to be f_L(Bs->D_s*- rho+)=1.05 +0.08-0.10(stat.)\n+0.03-0.04(syst.). These results are based on a 23.6 /fb data sample collected\nat the Y(5S) resonance with the Belle detector at the KEKB e+e- collider.", "category": "hep-ex" }, { "text": "Observation of a resonance X(1835) in J/\u03c8--> \u03b3\u03c0^+ \u03c0^-\n \u03b7^{\\prime}: The decay channel J/\\psi --> \\gamma \\pi^+ \\pi^- \\eta^{\\prime} is analyzed\nusing a sample of 5.8\\times 10^7 J\\psi events collected with the BESII\ndetector. A resonance, the X(1835), is observed in the \\pi^+ \\pi^-\n\\eta^{\\prime} invariant mass spectrum with a statistical significance of 7.7\n\\sigma. A fit with a Breit-Wigner function yields a mass M = 1833.7 \\pm\n6.1(stat) \\pm 2.7(syst) MeV/c^2, a width \\Gamma = 67.7 \\pm 20.3(stat) \\pm\n7.7(syst) MeV/c^2 and a product branching fraction B(J/\\psi --> \\gamma X) B(X\n--> \\pi^+ \\pi^- \\eta^{\\prime}) = (2.2 \\pm 0.4(stat) \\pm 0.4(syst)) \\times\n10^{-4}. The mass and width of the X(1835) are not compatible with any known\nmeson resonance. Its properties are consistent with expectations for the state\nthat produces the strong p\\bar{p} mass threshold enhancement observed in the\nJ\\psi -->\\gamma p \\bar{p} process at BESII.", "category": "hep-ex" }, { "text": "Study of the Reaction $np \\rightarrow np \u03c0^+ \u03c0^-$ at Intermediate\n Energies: The reaction $np \\rightarrow np \\pi^+ \\pi^-$ was studied at the various\nmomenta of incident neutrons. It was shown that the characteristics of the\nreaction at the momenta above 3 GeV/c could be described by the model of\nreggeized $\\pi$ exchange (OPER). At the momenta below 3 GeV/c, it was necessary\nto use additionally the mechanism of one baryon exchange (OBE).", "category": "hep-ex" }, { "text": "A Measurement of CP Asymmetry in b->sgamma using a Sum of Exclusive\n Final States: We perform a measurement of the CP asymmetry in b->sgamma decays using a\nsample of 383 BB events collected by the BABAR detector at the PEP-II\nasymmetric B factory. We reconstruct sixteen flavor-specific B decay modes\ncontaining a high-energy photon and a hadronic system (Xs) containing an s\nquark. We measure the \\CP asymmetry to be -0.011+/- 0.030(stat)+/-0.014(syst)\nfor a photon energy threshold at 1.6 GeV and the hadronic system mass between\n0.6 and 2.8 GeV/c2.", "category": "hep-ex" }, { "text": "Moriond 2012, QCD and High Energy Interactions: Baryonic B decays at\n BaBar: We report on the analyses of the baryonic B decays B0bar -> LambdaC+ p- p+ p-\nand B- -> SigmaC++ p- pi- pi-. The underlying data sample consists of 470 x\n10^6 BBbar pairs generated in the process e+e- -> Y(4S) and collected with the\nBaBar detector at the PEP-II storage ring at SLAC. We find BR(B0bar -> LambdaC+\np- p+ p-) x BR(LambdaC+ -> p+ K- pi+) / 5% < 6.2 x 10^(-6) @ CL=90% and BR(B-\n-> SigmaC++ p- pi- pi-) = [2.98 +/- 0.16(stat) +/- 0.15(syst) +/-\n0.77(LambdaC+)] x 10^(-4), where the last error is due to the uncertainty in\nBR(LambdaC+ -> p+ K- pi+). The data suggest the existence of resonant\nsubchannels B- -> LambdaC(2595)+ p- pi- and, possibly, B- -> SigmaC++\nanti-Delta-- pi-. We see unexplained structures in m(SigmaC++ pi- pi-) at 3.25\nGeV/c^2, 3.8 GeV/c^2, and 4.2 GeV/c^2.", "category": "hep-ex" }, { "text": "Unambiguously Resolving the Potential Neutrino Magnetic Moment Signal at\n Large Liquid Scintillator Detectors: Non-vanishing electromagnetic properties of the neutrinos have been predicted\nby many theories beyond the Standard Model, and an enhanced neutrino magnetic\nmoment can have profound implications for fundamental physics. The XENON1T\nexperiment recently detected an excess of electron recoil events in the 1-7 keV\nenergy range, which can be compatible with solar neutrino magnetic moment\ninteraction at a most probable value of $\\mu_{\\nu} = 2.1 \\times 10^{-11}\n\\mu_{\\text{B}}$. However, tritium backgrounds and solar axion interaction in\nthis energy window are equally plausible causes. Upcoming multi-tonne noble\nliquid detectors will test these scenarios more in depth, but will continue to\nface similar ambiguity. We report a unique capability of future large liquid\nscintillator detectors to help resolve the potential neutrino magnetic moment\nscenario. With a liquid scintillator exposure of $O$(100) kton$\\cdot$year, a\nsensitivity of $\\mu_{\\nu} < 10^{-11} \\mu_{\\text{B}}$ can be reached at an\nenergy threshold greater than 40 keV, where no tritium or solar axion events\nbut only neutrino magnetic moment signal is still present.", "category": "hep-ex" }, { "text": "Light Hadron Spectroscopy and Decay at BESIII: Light hadron spectroscopy plays an important role in understanding the decay\ndynamics of unconventional hadronic states, such as strangeonium and glueballs.\nBESIII provides an ideal avenue to search for these exotic states thanks to a\nhuge amount of data recorded at various energy points in the tau-charm mass\nregion including J/psi resonance. This report summarizes recent results of the\nBESIII experiment related to the glueballs and strangeonium-like states.", "category": "hep-ex" }, { "text": "Search for top squarks in final states with two top quarks and several\n light-flavor jets in proton-proton collisions at $\\sqrt{s} =$ 13 TeV: Many new physics models, including versions of supersymmetry characterized by\n$R$-parity violation (RPV), compressed mass spectra, long decay chains, or\nadditional hidden sectors, predict the production of events with top quarks,\nlow missing transverse momentum, and many additional quarks or gluons. The\nresults of a search for new physics in events with two top quarks and\nadditional jets are reported. The search is performed using events with at\nleast seven jets and exactly one electron or muon. No requirement on missing\ntransverse momentum is imposed. The study is based on a sample of proton-proton\ncollisions at $\\sqrt{s} =$ 13 TeV corresponding to 137 fb$^{-1}$ of integrated\nluminosity collected with the CMS detector at the LHC in 2016-2018. The data\nare used to determine best fit values and upper limits on the cross section for\npair production of top squarks in scenarios of RPV and stealth supersymmetry.\nTop squark masses up to 670 (870) GeV are excluded at 95% confidence level for\nthe RPV (stealth) scenario, and the maximum observed local signal significance\nis 2.8 standard deviations for the RPV scenario with top squark mass of 400\nGeV.", "category": "hep-ex" }, { "text": "Updated Combination of CDF and D0 Searches for Standard Model Higgs\n Boson Production with up to 10.0 fb-1 of Data: We combine results from the CDF and D0 Collaborations on direct searches for\nthe standard model (SM) Higgs boson (H) in ppbar collisions at the Fermilab\nTevatron at sqrt(s)=1.96 TeV. Compared to the previous Tevatron Higgs boson\nsearch combination, more data have been included, additional channels have been\nincorporated, and some previously used channels have been reanalyzed to gain\nsensitivity. Searches are carried out for hypothesized Higgs boson masses\nbetween 100 and 200 GeV/c^2. With up to 10 fb-1 of luminosity analyzed, the 95%\nC.L. median expected upper limits on Higgs boson production are factors of\n0.89, 1.08, and 0.48 times the values of the SM cross section for Higgs bosons\nof mass m_H=115 GeV/c^2, 125 GeV/c^2, and 165 GeV/c^2, respectively. In the\nabsence of signal, we expect to exclude the regions 1004l) for certain values of its mass.", "category": "hep-ex" }, { "text": "The LHCB Commissioning: The LHCb experiment is dedicated to precision measurements of CP violation\nand rare decays of B hadrons at the Large Hadron Collider (LHC) at CERN. The\nLHCb installation has been finished in spring 2008 and an intensive testing and\ncommissioning of the system has been started. An overview and the results from\nour commissioning activities are described.", "category": "hep-ex" }, { "text": "Measurement of Trilinear Gauge Boson Couplings WWV, (V = Z,gamma) in\n e+e- Collisions at 189 GeV: Measurements of the trilinear gauge boson couplings WWgamma and WWZ are\npresented using the data taken by DELPHI in 1998 at a centre-of-mass energy of\n189 GeV and combined with DELPHI data at 183 GeV. Values are determined for\nDelta(g_1^Z) and Delta(kappa_gamma), the differences of the WWZ charge coupling\nand of the WWgamma dipole coupling from their Standard Model values, and for\nlambda_gamma, the WWgamma quadrupole coupling. A measurement of the magnetic\ndipole and electric quadrupole moment of the W is extracted from the results\nfor Delta(kappa_gamma) and lambda_gamma. The study uses data from the final\nstates jjlv, jjjj, lX, jjX and gammaX, where j represents a quark jet, l an\nidentified lepton and X missing four-momentum. The observations are consistent\nwith the predictions of the Standard Model.", "category": "hep-ex" }, { "text": "Measurements of the reaction $\\bar{p}p \\to \u03c6\u03b7$ of antiproton\n annihilation at rest at three hydrogen target densities: The proton-antiproton annihilation at rest into the $\\phi\\eta$ final state\nwas measured for three different target densities: liquid hydrogen, gaseous\nhydrogen at NTP and at a low pressure of 5 mbar. The yield of this reaction in\nthe liquid hydrogen target is smaller than in the low-pressure gas target. The\nbranching ratios of the $\\phi\\eta$ channel were calculated on the basis of\nsimultaneous analysis of the three data samples. The branching ratio for\nannihilation into $\\phi\\eta$ from the $^3S_1$ protonium state turns out to be\nabout ten times smaller as compared to the one from the $^1P_1$ state.", "category": "hep-ex" }, { "text": "Evidence for new interference phenomena in the decay D+ to K- pi+ mu+ nu: Using a large sample of charm semileptonic decays collected by the FOCUS\nphotoproduction experiment at Fermilab, we present evidence for a small, even\nspin K- \\pi+ amplitude that interferes with the dominant K*0 component in the\nK-pi+ mu- nu final state. Although this interference significantly distorts the\ndecay angular distributions, the new amplitude creates only a very small\ndistortion to the observed kaon pion mass distribution when integrated over the\nother kinematic variables describing the decay. Our data can be described by\nK*0 interference with either a constant amplitude or broad spin zero resonance.", "category": "hep-ex" }, { "text": "New PVLAS results and limits on magnetically induced optical rotation\n and ellipticity in vacuum: IIn 2006 the PVLAS collaboration reported the observation of an optical\nrotation generated in vacuum by a magnetic field. To further check against\npossible instrumental artifacts several upgrades to the PVLAS apparatus have\nbeen made during the last year. Two data taking runs, at the wavelength of 1064\nnm, have been performed in the new configuration with magnetic field strengths\nof 2.3 T and 5 T. The 2.3 T field value was chosen in order to avoid stray\nfields. The new observations do not show the presence of a rotation signal down\nto the levels of $1.2\\cdot 10^{-8}$ rad at 5 T and $1.0\\cdot 10^{-8}$ rad at\n2.3 T (at 95% c.l.) with 45000 passes in the magnetic field zone. In the same\nconditions no ellipticity signal was detected down to $1.4\\cdot 10^{-8}$ at 2.3\nT (at 95% c.l.), whereas at 5 T a signal is still present. The physical nature\nof this ellipticity as due to an effect depending on $B^2$ can be excluded by\nthe measurement at 2.3 T. These new results completely exclude the previously\npublished magnetically induced vacuum dichroism results, indicating that they\nwere instrumental artifacts. These new results therefore also exclude the\nparticle interpretation of the previous PVLAS results as due to a spin zero\nboson. The background ellipticity at 2.3 T can be used to determine a new limit\non the total photon-photon scattering cross section of $\\sigma_{\\gamma\\gamma} <\n4.5 \\cdot10^{-34}$ barn at 95% c.l..", "category": "hep-ex" }, { "text": "Search for the Weak Decay of a Lightly Bound H Dibaryon: We present results of a search for a neutral, six-quark, dibaryon state\ncalled the \\h, a state predicted to exist in several theoretical models.\nObservation of such a state would signal the discovery of a new form of\nhadronic matter. Analyzing data collected by experiment E799-II, using the KTeV\ndetector at Fermilab, we searched for the decay $H^0 \\to \\Lambda p \\piminus$\nand found no candidate events. We exclude the region of lightly bound mass\nstates just below the $\\Lambda\\Lambda$ mass threshold, $2.194~\\gev < M_H <\n2.231$~\\gev, with lifetimes from $\\sim$$ 5 \\times 10^{-10}$~sec to $\\sim$$1\n\\times 10^{-3}$~sec.", "category": "hep-ex" }, { "text": "Precision Measurement of B(D+ -> mu+ nu) and the Pseudoscalar Decay\n Constant fD+: We measure the branching ratio of the purely leptonic decay of the D+ meson\nwith unprecedented precision as B(D+ -> mu+ nu) = (3.82 +/- 0.32 +/-\n0.09)x10^(-4), using 818/pb of data taken on the psi(3770) resonance with the\nCLEO-c detector at the CESR collider. We use this determination to derive a\nvalue for the pseudoscalar decay constant fD+, combining with measurements of\nthe D+ lifetime and assuming |Vcd| = |Vus|. We find fD+ = (205.8 +/- 8.5 +/-\n2.5) MeV. The decay rate asymmetry [B(D+ -> mu+ nu)-B(D- -> mu- nu)]/[B(D+ ->\nmu+ nu)+B(D- -> mu- nu)] = 0.08 +/- 0.08, consistent with no CP violation. We\nalso set 90% confidence level upper limits on B(D+ -> tau+ nu) < 1.2x10^(-3)\nand B(D+ -> e+ nu) < 8.8x10^(-6).", "category": "hep-ex" }, { "text": "Observation of two resonances in the $\u039b_b^0 \u03c0^\\pm$ systems and\n precise measurement of $\u03a3_b^\\pm$ and $\u03a3_b^{*\\pm}$ properties: The first observation of two structures consistent with resonances in the\nfinal states $\\Lambda_b^0 \\pi^-$ and $\\Lambda_b^0 \\pi^+$ is reported using\nsamples of $pp$ collision data collected by the LHCb experiment at $\\sqrt{s} =\n7$ and $8$ TeV, corresponding to an integrated luminosity of 3\n$\\mathrm{fb}^{-1}$. The ground states $\\Sigma_b^\\pm$ and $\\Sigma_b^{*\\pm}$ are\nalso confirmed and their masses and widths are precisely measured.", "category": "hep-ex" }, { "text": "Transverse Spin Studies with STAR at RHIC: STAR has observed sizable transverse single-spin asymmetries for inclusive\npi^0 production at forward rapidity in p+p collisions at sqrt{s}=200 GeV. These\nasymmetries may arise from either the Sivers or Collins effect. Studies are\nunderway during the current RHIC run to elucidate the dynamics that underlie\nthese single-spin asymmetries. Additional measurements are underway to search\nfor the Sivers effect in mid-rapidity di-jet production.", "category": "hep-ex" }, { "text": "Probing the BFKL dynamics at hadronic colliders: We describe different possibilities to probe the BFKL dynamics at hadronic\ncolliders, namely Mueller-Navelet jet, and jet gap jet events. We also discuss\nbriefly the jet veto measurement as performed by the ATLAS collaboration at the\nLHC.", "category": "hep-ex" }, { "text": "Measurements of top-quark pair to $Z$-boson cross-section ratios at\n $\\sqrt s = 13, 8, 7$TeV with the ATLAS detector: Ratios of top-quark pair to $Z$-boson cross sections measured from\nproton--proton collisions at the LHC centre-of-mass energies of $\\sqrt\ns=13$TeV, 8TeV, and 7TeV are presented by the ATLAS Collaboration. Single\nratios, at a given $\\sqrt s$ for the two processes and at different $\\sqrt s$\nfor each process, as well as double ratios of the two processes at different\n$\\sqrt s$, are evaluated. The ratios are constructed using previously published\nATLAS measurements of the $t\\overline{t}$ and $Z$-boson production cross\nsections, corrected to a common phase space where required, and a new analysis\nof $Z \\rightarrow \\ell^+ \\ell^-$ where $\\ell=e,\\mu$ at $\\sqrt s=13$TeV\nperformed with data collected in 2015 with an integrated luminosity of\n$3.2$fb$^{-1}$. Correlations of systematic uncertainties are taken into account\nwhen evaluating the uncertainties in the ratios. The correlation model is also\nused to evaluate the combined cross section of the $Z\\rightarrow e^+e^-$ and\nthe $Z\\rightarrow \\mu^+ \\mu^-$ channels for each $\\sqrt s$ value. The results\nare compared to calculations performed at next-to-next-to-leading-order\naccuracy using recent sets of parton distribution functions. The data\ndemonstrate significant power to constrain the gluon distribution function for\nthe Bjorken-$x$ values near 0.1 and the light-quark sea for $x<0.02$.", "category": "hep-ex" }, { "text": "The indication for $^{40}$K geo-antineutrino flux with Borexino\n phase-III data: We provide the indication of high flux of $^{40}$K geo-antineutrino and\ngeo-neutrino ($^{40}$K-geo-($\\bar{\\nu} + \\nu$)) with Borexino Phase III data.\nThis result was obtained by introducing a new source of single events, namely\n$^{40}$K-geo-($\\bar{\\nu} + \\nu$) scattering on electrons, in multivariate fit\nanalysis of Borexino Phase III data. Simultaneously we obtained the count rates\nof events from $^7$Be, $pep$ and CNO solar neutrinos. These count rates are\nconsistent with the prediction of the Low metallicity Sun model SSM B16-AGSS09.\nMC pseudo-experiments showed that the case of High metallicity Sun and absence\nof $^{40}$K-geo-($\\bar{\\nu} + \\nu$) can not imitate the result of multivariate\nfit analysis of Borexino Phase III data with introducing\n$^{40}$K-geo-($\\bar{\\nu} + \\nu$) events. We also provide arguments for the high\nabundance of potassium in the Earth.", "category": "hep-ex" }, { "text": "Observation of new baryons in the $\u039e_b^-\u03c0^+\u03c0^-$ and\n $\u039e_b^0\u03c0^+\u03c0^-$ systems: The first observation and study of two new baryonic structures in the final\nstate $\\Xi_b^0\\pi^+\\pi^-$ and the confirmation of the $\\Xi_b(6100)^-$ state in\nthe $\\Xi_b^-\\pi^+\\pi^-$ decay mode are reported using proton-proton collision\ndata collected by the LHCb experiment, corresponding to an integrated\nluminosity of 9$\\mathrm{fb}^{-1}$. In addition, the properties of the known\n$\\Xi_b^{*0}$, $\\Xi_b^{'-}$ and $\\Xi_b^{*-}$ resonances are measured with\nimproved precision. The new decay mode of the $\\Xi_b^0$ baryon to the\n$\\Xi_c^+\\pi^-\\pi^+\\pi^-$ final state is observed and exploited for the first\ntime in these measurements.", "category": "hep-ex" }, { "text": "Review of physics results from the Tevatron: QCD physics: We present a summary of results from studies of quantum chromodynamics at the\nFermilab Tevatron collider by the CDF and the D0 experiments. These include Run\nII results for the time period up to the end of Summer 2014. A brief\ndescription of Run I resultsis also given. This review covers a wide spectrum\nof topics, and includes measurements with jet and vector boson final states in\nthe hard (perturbative) energy regime, as well as studies of soft physics such\nas diffractive and elastic scatterings, underlying and minimum bias events,\nhadron fragmentation, and multiple parton interactions.", "category": "hep-ex" }, { "text": "Search for WH associated production at D\u00f8 Tevatron: The Higgs mechanism introduced in 1964 gives a satisfactory solution to a\nmajor problem of the standard model of elementary particles: the origin of the\nmass. It predicts the existence of the Higgs scalar boson, which has not been\ndiscovered experimentally yet. The Tevatron, a hadron accelerator based at\nFermi National Accelerator Laboratory near Chicago, has delivered data to its\ntwo multi-purpose detectors CDF and DZERO since 1983 up to september 2011.\nLeaving us about 11 fb-1 of data per experiment to analyze. Associated\nproduction of a Higgs boson and a vector gauge boson W or Z is the main search\nchannel for a light standard Higgs boson (i.e. below 135 GeV/c2). Using data\ncollected by DZERO, we are looking for this production mode taking advantage of\nsophisticated techniques to improve the signal sensitivity such as b-jet\nidentification and multivariate discriminants. In the end, a statistical\napproach allows us to set an upper limit on the ratio between the observed\n(resp. expected) Higgs production cross section and its theoretical cross\nsection. The latest result obtained in the WH channel using 8.5 f b-1 at DZERO\nis 4.6 (resp. 3.5) for a 115 GeV/c2 Higgs boson.", "category": "hep-ex" }, { "text": "Experimental results on $K_L$ decays: Recent measurements by the NA48 at CERN of selected $K_L$ decays are\npresented. These are the branching ratios and form factors for channels $K_L\\to\n\\pi^{\\pm}\\pi^0\\e^{\\mp}\\nu_e$ (final result), $K_L\\to\\pi^{\\pm}e^{\\mp}\\nu_e$ and\n$K_L\\to e^+e^-e^+e^-$ (preliminary results).", "category": "hep-ex" }, { "text": "Measurement of the production cross section for $Z/\u03b3^*$ in\n association with jets in pp collisions at $\\sqrt{s}$ = 7 TeV with the ATLAS\n Detector: We present results on the production of jets of particles in association with\na $Z/\\gamma^*$ boson, in proton-proton collisions at $\\sqrt{s} = 7$ TeV with\nthe ATLAS detector at the LHC. The analysis includes the full 2010 data set,\ncollected with a low rate of multiple proton-proton collisions in the\naccelerator, corresponding to an integrated luminosity of $36 \\rm pb^{-1}$.\nInclusive jet cross sections in $Z/\\gamma^*$ events, with $Z/\\gamma^*$ decaying\ninto electron or muon pairs, are measured for jets with transverse momentum\n$p_T >$ 30 GeV and jet rapidity $|y| < 4.4$. The measurements are compared to\nnext-to-leading-order perturbative QCD calculations, and to predictions from\ndifferent Monte Carlo generators implementing leading-order matrix elements\nsupplemented by parton showers.", "category": "hep-ex" }, { "text": "Future Polarised DIS Fixed Target Experiments: New experiments in polarised deep inelastic scattering will mainly\nconcentrate on the measurement of semi-inclusive asymmetries. Especially, the\nupgraded HERMES experiment at DESY and the newly build COMPASS experiment at\nCERN will investigate the gluon polarisation via open charm and high p_T hadron\npair production, study in detail the flavour decomposition of the quark\nhelicity distributions and measure the tranversity distributions with\ntranversely polarised targets.", "category": "hep-ex" }, { "text": "Search for a Charged Higgs Boson Produced in the Vector-boson Fusion\n Mode with Decay $H^\\pm \\to W^\\pm Z$ using $pp$ Collisions at $\\sqrt{s}=8$ TeV\n with the ATLAS Experiment: A search for a charged Higgs boson, $H^\\pm$, decaying to a $W^\\pm$ boson and\na $Z$ boson is presented. The search is based on 20.3 fb$^{-1}$ of\nproton-proton collision data at a center-of-mass energy of 8 TeV recorded with\nthe ATLAS detector at the LHC. The $H^\\pm$ boson is assumed to be produced via\nvector-boson fusion and the decays $W^\\pm \\to q\\bar{q^\\prime}$ and\n$Z\\rightarrow e^+e^-/\\mu^+\\mu^-$ are considered. The search is performed in a\nrange of charged Higgs boson masses from 200 to 1000 GeV. No evidence for the\nproduction of an $H^\\pm$ boson is observed. Upper limits of 31-1020 fb at 95%\nCL are placed on the cross section for vector-boson fusion production of an\n$H^\\pm$ boson times its branching fraction to $W^\\pm Z$. The limits are\ncompared with predictions from the Georgi-Machacek Higgs Triplet Model.", "category": "hep-ex" }, { "text": "First background-free limit from a directional dark matter experiment:\n results from a fully fiducialised DRIFT detector: The addition of O2 to gas mixtures in time projection chambers containing CS2\nhas recently been shown to produce multiple negative ions that travel at\nslightly different velocities. This allows a measurement of the absolute\nposition of ionising events in the z (drift) direction. In this work, we apply\nthe z-fiducialisation technique to a directional dark matter search. In\nparticular, we present results from a 46.3 live-day source-free exposure of the\nDRIFT-IId detector run in this completely new mode. With full-volume\nfiducialisation, we have achieved the first background-free operation of a\ndirectional detector. The resulting exclusion curve for spin-dependent\nWIMP-proton interactions reaches 1.1 pb at 100 GeV/c2, a factor of 2 better\nthan our previous work. We describe the automated analysis used here, and argue\nthat detector upgrades, implemented after the acquisition of these data, will\nbring an additional factor of >3 improvement in the near future.", "category": "hep-ex" }, { "text": "Search for a Higgs Boson Decaying into Two Photons at LEP: A Higgs particle produced in association with a Z boson and decaying into two\nphotons is searched for in the data collected by the L3 experiment at LEP. All\npossible decay modes of the Z boson are investigated. No signal is observed in\n447.5 pb^-1 of data recorded at centre-of-mass energies up to 209 GeV. Limits\non the branching fraction of the Higgs boson decay into two photons as a\nfunction of the Higgs mass are derived. A lower limit on the mass of a\nfermiophobic Higgs boson is set at 105.4 GeV at 95% confidence level.", "category": "hep-ex" }, { "text": "Evidence for the direct decay of the 125 GeV Higgs boson to fermions: The discovery of a new boson with a mass of approximately 125 GeV in 2012 at\nthe LHC has heralded a new era in understanding the nature of electroweak\nsymmetry breaking and possibly completing the standard model of particle\nphysics. Since the first observation in decays to gamma gamma, WW, and ZZ boson\npairs, an extensive set of measurements of the mass and couplings to W and Z\nbosons, as well as multiple tests of the spin-parity quantum numbers, have\nrevealed that the properties of the new boson are consistent with those of the\nlong-sought agent responsible for electroweak symmetry breaking. An important\nopen question is whether the new particle also couples to fermions, and in\nparticular to down-type fermions, since the current measurements mainly\nconstrain the couplings to the up-type top quark. Determination of the\ncouplings to down-type fermions requires direct measurement of the\ncorresponding Higgs boson decays, as recently reported by the CMS experiment in\nthe study of Higgs decays to bottom quarks and tau leptons. In this paper we\nreport the combination of these two channels which results, for the first time,\nin strong evidence for the direct coupling of the 125 GeV Higgs boson to\ndown-type fermions, with an observed significance of 3.8 standard deviations,\nwhen 4.4 are expected.", "category": "hep-ex" }, { "text": "Search for Leptoquarks in Electron-Photon Scattering at sqrt(s_ee) up to\n 209 GeV at LEP: Searches for first generation scalar and vector leptoquarks, and for squarks\nin R-parity violating SUSY models with the direct decay of the squark into\nStandard Model particles, have been performed using e+e- collisions collected\nwith the OPAL detector at LEP at e+e- centre-of-mass energies between 189 and\n209 GeV. No excess of events is found over the expectation from Standard Model\nbackground processes. Limits are computed on the leptoquark couplings for\ndifferent values of the branching ratio to electron-quark final states.", "category": "hep-ex" }, { "text": "Search for Electron Neutrino Appearance in a 250 km Long-baseline\n Experiment: We present a search for electron neutrino appearance from accelerator\nproduced muon neutrinos in the K2K long baseline neutrino experiment. One\ncandidate event is found in the data corresponding to an exposure of 4.8*10^19\nprotons on target. The expected background in the absence of neutrino\noscillations is estimated to be 2.4+-0.6 events and is dominated by\nmis-identification of events from neutral current pi^0 production. We exclude\nthe \\nu_\\mu to \\nu_e oscillations at 90% C.L. for the effective mixing angle in\n2-flavor approximation of sin^2(2theta_\\mu_e) (~= 1/2 sin^2 2 th_13) > 0.15 at\nDelta m^2_\\mu_e = 2.8*10^{-3} eV^2, the best fit value of the \\nu_\\mu\ndisappearance analysis in K2K. The most stringent limit of sin^2(2theta_\\mu_e)\n< 0.09 is obtained at Delta m^2_\\mu_e = 6*10^{-3} eV^2.", "category": "hep-ex" }, { "text": "Search for high-mass resonances in final states with a lepton and\n missing transverse momentum at $\\sqrt{s}=$ 13 TeV: A search for new high-mass resonances in proton-proton collisions having\nfinal states with an electron or muon and missing transverse momentum is\npresented. The analysis uses proton-proton collision data collected in 2016\nwith the CMS detector at the LHC at a center-of-mass energy of 13 TeV,\ncorresponding to an integrated luminosity of 35.9 fb$^{-1}$. The transverse\nmass distribution of the charged lepton-neutrino system is used as the\ndiscriminating variable. No significant deviation from the standard model\nprediction is found. The best limit, from the combination of electron and muon\nchannels, is 5.2 TeV at 95% confidence level for the mass of a W$'$ boson with\nthe same couplings as those of the standard model W boson. Exclusion limits of\n2.9 TeV are set on the inverse radius of the extra dimension in the framework\nof split universal extra dimensions. In addition, model-independent limits are\nset on the production cross section and coupling strength of W$'$ bosons\ndecaying into this final state. An interpretation is also made in the context\nof an R parity violating supersymmetric model with a slepton as a mediator and\nflavor violating decay.", "category": "hep-ex" }, { "text": "Measurement of the effective weak mixing angle at the CEPC: We present a study of the measurement of the effective weak mixing angle\nparameter ($\\sin^2\\theta^{\\ell}_\\text{eff}$) at the Circular Electron Positron\nCollider (CEPC). As a fundamental physics parameter,\n$\\sin^2\\theta^{\\ell}_\\text{eff}$ plays a key role not only in the global test\nof the standard model electroweak sector, but also in constraining the\npotential beyond standard model new physics at high energy frontier. CEPC\nproposes a two year running period around the Z boson mass pole at high\ninstataneous luminosity, providing a large data sample with $4\\times 10^{12}$\n$Z$ candidates generated in total. It allows a high precision measurement of\n$\\sin^2\\theta^{\\ell}_\\text{eff}$ both in the lepton and quark final states, of\nwhich the uncertainty can be one order of magnitude lower than any previous\nmeasurement at the LEP, SLC, Tevatron and LHC. It will not only improve the\noverall precision of the $\\sin^2\\theta^\\ell_\\text{eff}$ experimental\ndetermination to be comparable to the preicision of the theoretical calculation\nwith two-loop radiative corrections, but also provide direct comparisons\nbetween different final states. In this paper, we also study the measurement of\n$\\sin^2\\theta^{\\ell}_\\text{eff}$ at high mass region. With one month data\ntaken, the precision of $\\sin^2\\theta^{\\ell}_\\text{eff}$ measured at 130 GeV\nfrom $b$ quark final state is 0.00010, which will be an important experimental\nobservation on the energy-running effect of $\\sin^2\\theta^{\\ell}_\\text{eff}$.", "category": "hep-ex" }, { "text": "Total Cross Section in gamma gamma Collisions at LEP: The reaction e+e- -> e+e- gamma* gamma* -> e+e- hadrons for quasi-real\nphotons is studied using data from root(s) = 183 GeV up to 202 GeV.\n Results on the total cross sections sigma(e+e- -> e+e- hadrons) and sigma(+e-\ngamma* gamma* -> e+e- hadrons) are given for the two-photon centre-of-mass\nenergies 5 GeV < Wgammagamma < 185 GeV.\n The total cross section of two real photons is described by a Regge\nparametrisation. We observe a steeper rise with the two-photon centre-of-mass\nenergy as compared to the hadron-hadron and the photon-proton cross sections.\nThe data are also compared to the expectations of different theoretical models.", "category": "hep-ex" }, { "text": "Measurement of associated production of vector bosons and top\n quark-antiquark pairs at sqrt(s) = 7 TeV: The first measurement of vector-boson production associated with a top\nquark-antiquark pair in proton-proton collisions at sqrt(s) = 7 TeV is\npresented. The results are based on a data set corresponding to an integrated\nluminosity of 5.0 inverse femtobarms, recorded by the CMS detector at the LHC\nin 2011. The measurement is performed in two independent channels through a\ntrilepton analysis of t t-bar Z events and a same-sign dilepton analysis of t\nt-bar V (V = W or Z) events. In the trilepton channel a direct measurement of\nthe t t-bar Z cross section sigma(t t-bar Z) = 0.28 +0.14/-0.11 (stat)\n+0.06/-0.03 (syst) pb is obtained. In the dilepton channel a measurement of the\nt t-bar V cross section yields sigma(t t-bar V) = 0.43 +0.17/-0.15 (stat)\n+0.09/-0.07 (syst) pb. These measurements have a significance, respectively, of\n3.3 and 3.0 standard deviations from the background hypotheses and are\ncompatible, within uncertainties, with the corresponding next-to-leading order\npredictions of 0.137 +0.012/-0.016 and 0.306 +0.031/-0.053 pb.", "category": "hep-ex" }, { "text": "Evidence for $B^0 \\to \u03c7_{c1} \u03c0^0$ at Belle: We present a measurement of the branching fraction for the Cabibbo- and\ncolor-suppressed $B^0 \\to \\chi_{c1}\\pi^0$ decay based on a data sample of\n$657\\times 10^6$ $B\\bar B$ events collected at the $\\Upsilon(4S)$ resonance\nwith the Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider. We\nobserve a signal of $40\\pm9$ events with a significance of $4.7\\sigma$\nincluding systematic uncertainties. The measured branching fraction is\n$\\mathcal {B}(B^0 \\to \\chi_{c1} \\pi^0) = (1.12\\pm 0.25(\\rm {stat.})\\pm\n0.12({\\rm syst.}))\\times 10^{-5}$.", "category": "hep-ex" }, { "text": "The differential production cross section of the phi(1020) meson in\n sqrt(s)=7 TeV pp collisions measured with the ATLAS detector: A measurement is presented of the phi to K+K- production cross section at\nsqrt(s) = 7 TeV using pp collision data corresponding to an integrated\nluminosity of 383 mub-1, collected with the ATLAS experiment at the LHC.\nSelection of phi(1020) mesons is based on the identification of charged kaons\nby their energy loss in the pixel detector. The differential cross section is\nmeasured as a function of the transverse momentum, pTphi, and rapidity, |yphi|,\nof the phi(1020) meson in the fiducial region 500 < pTphi< 1200 MeV, |yphi| <\n0.8, kaon pTK> 230 MeV and kaon momentum pK< 800 MeV.The integrated\nphi(1020)-meson production cross section in this fiducial range is measured to\nbe s(phi K+K-) = 570 pm 8 (stat) pm 66 (syst) pm 20 (lumi) mub.", "category": "hep-ex" }, { "text": "New physics limits from kaon decays: Searches for lepton flavour violation and lepton number violation in kaon\ndecays by the NA62 and NA48/2 experiments at CERN are presented. A new\nmeasurement of the ratio of charged kaon leptonic decay rates\n$R_K=\\Gamma(K_{e2})/\\Gamma(K_{\\mu2})$ to sub-percent relative precision is\ndiscussed. An improved upper limit on the lepton number violating\n$K^\\pm\\rightarrow\\pi^\\mp\\mu^\\pm\\mu^\\pm$ decay rate is also reported. The future\n10% precision measurement of the branching ratio of the ultra-rare kaon decay\n$K^+\\rightarrow\\pi^+\\nu\\bar{\\nu}$ with the NA62 experiment is finally reviewed.", "category": "hep-ex" }, { "text": "Limits on Interactions between Weakly Interacting Massive Particles and\n Nucleons Obtained with NaI(Tl) crystal Detectors: Limits on the cross section for weakly interacting massive particles (WIMPs)\nscattering off nucleons in the NaI(Tl) detectors at the Yangyang Underground\nLaboratory are obtained with a 2967.4 kg*day data exposure. Nuclei recoiling\nare identified by the pulse shape of scintillating photon signals. Data are\nconsistent with no nuclear recoil hypothesis, and 90% confidence level upper\nlimits are set. These limits partially exclude the DAMA/LIBRA region of\nWIMP-sodium interaction with the same NaI(Tl) target detector. This 90%\nconfidence level upper limit on WIMP-nucleon spin-independent cross section is\n3.26*10^-4 pb for a WIMP mass at 10 GeV/c^2.", "category": "hep-ex" }, { "text": "A Combined $\u03bd_\u03bc\\to \u03bd_e$ and $\\bar\u03bd_\u03bc\\to \\bar\u03bd_e$\n Oscillation Analysis of the MiniBooNE Excesses: The MiniBooNE experiment at Fermilab reports results from an analysis of the\ncombined $\\nu_e$ and $\\bar \\nu_e$ appearance data from $6.46 \\times 10^{20}$\nprotons on target in neutrino mode and $11.27 \\times 10^{20}$ protons on target\nin antineutrino mode. A total excess of $240.3 \\pm 34.5 \\pm 52.6$ events ($3.8\n\\sigma$) is observed from combining the two data sets in the energy range\n$200 4.3 10^{31} years at 90% CL with no background subtraction.", "category": "hep-ex" }, { "text": "Proposal to Search for Heavy Neutral Leptons at the SPS: A new fixed-target experiment at the CERN SPS accelerator is proposed that\nwill use decays of charm mesons to search for Heavy Neutral Leptons (HNLs),\nwhich are right-handed partners of the Standard Model neutrinos. The existence\nof such particles is strongly motivated by theory, as they can simultaneously\nexplain the baryon asymmetry of the Universe, account for the pattern of\nneutrino masses and oscillations and provide a Dark Matter candidate.\n Cosmological constraints on the properties of HNLs now indicate that the\nmajority of the interesting parameter space for such particles was beyond the\nreach of the previous searches at the PS191, BEBC, CHARM, CCFR and NuTeV\nexperiments. For HNLs with mass below 2 GeV, the proposed experiment will\nimprove on the sensitivity of previous searches by four orders of magnitude and\nwill cover a major fraction of the parameter space favoured by theoretical\nmodels.\n The experiment requires a 400 GeV proton beam from the SPS with a total of\n2x10^20 protons on target, achievable within five years of data taking. The\nproposed detector will reconstruct exclusive HNL decays and measure the HNL\nmass. The apparatus is based on existing technologies and consists of a target,\na hadron absorber, a muon shield, a decay volume and two magnetic\nspectrometers, each of which has a 0.5 Tm magnet, a calorimeter and a muon\ndetector. The detector has a total length of about 100 m with a 5 m diameter.\nThe complete experimental set-up could be accommodated in CERN's North Area.\n The discovery of a HNL would have a great impact on our understanding of\nnature and open a new area for future research.", "category": "hep-ex" }, { "text": "Observation of 1^-0^- Final States from psi(2S) Decays and e^+e^-\n Annihilation: Using CLEO data collected from CESR e+e- collisions at the Psi(2S) resonance\nand nearby continuum at E_CM=3.67GeV, we report the first significantly\nnon-zero measurements of light vector-pseudoscalar hadron pair production\n(including RhoPi, OmegaPi, RhoEta, and K*0K0bar) and the Pi+Pi-Pi0 final state,\nboth from Psi(2S) decays and direct e+e- annihilation.", "category": "hep-ex" }, { "text": "IceCube Sterile Neutrino Searches: Anomalies in short baseline experiments have been interpreted as evidence for\nadditional neutrino mass states with large mass splittings from the known,\nactive flavors. This explanation mandates a corresponding signature in the muon\nneutrino disappearance channel, which has yet to be observed. Searches for muon\nneutrino disappearance at the IceCube neutrino telescope presently provide the\nstrongest limits in the space of mixing angles for eV-scale sterile neutrinos.\nThis proceeding for the Very Large Volume Neutrino Telescopes (VLVnT) Workshop\nsummarizes the IceCube analyses that have searched for sterile neutrinos and\ndescribes ongoing work toward enhanced, high-statistics sterile neutrino\nsearches.", "category": "hep-ex" }, { "text": "Search for the Decay $B_s^0 \\rightarrow \u03b7^\\prime \u03b7$: We report the results of the first search for the decay $B_s^0 \\rightarrow\n\\eta^\\prime \\eta$ using $121.4~\\textrm{fb}^{-1}$ of data collected at the\n$\\Upsilon(5S)$ resonance with the Belle detector at the KEKB asymmetric-energy\n$e^+e^-$ collider. We observe no significant signal and set a 90\\%\nconfidence-level upper limit of %$7.1 \\times 10^{-5}$ $6.5 \\times 10^{-5}$ on\nthe branching fraction of this decay.", "category": "hep-ex" }, { "text": "b-Jet Identification in the D0 Experiment: Algorithms distinguishing jets originating from b quarks from other jet\nflavors are important tools in the physics program of the D0 experiment at the\nFermilab Tevatron p-pbar collider. This article describes the methods that have\nbeen used to identify b-quark jets, exploiting in particular the long lifetimes\nof b-flavored hadrons, and the calibration of the performance of these\nalgorithms based on collider data.", "category": "hep-ex" }, { "text": "Search for multi-messenger signals in NOvA coincident with LIGO/Virgo\n detections: Using the NOvA neutrino detectors, a broad search has been performed for any\nsignal coincident with 28 gravitational wave events detected by the LIGO/Virgo\nCollaboration between September 2015 and July 2019. For all of these events,\nNOvA is sensitive to possible arrival of neutrinos and cosmic rays of GeV and\nhigher energies. For five (seven) events in the NOvA Far (Near) Detector,\ntimely public alerts from the LIGO/Virgo Collaboration allowed recording of\nMeV-scale events. No signal candidates were found.", "category": "hep-ex" }, { "text": "Search for single production of vector-like quarks decaying into $Wb$ in\n $pp$ collisions at $\\sqrt{s} =$ 8 TeV with the ATLAS detector: A search for singly produced vector-like $Q$ quarks, where $Q$ can be either\na $T$ quark with charge $+2/3$ or a $Y$ quark with charge $-4/3$, is performed\nin proton-proton collisions recorded with the ATLAS detector at the LHC. The\ndataset corresponds to an integrated luminosity of 20.3 fb$^{-1}$ and was\nproduced with a centre-of-mass energy of $\\sqrt{s}=8$ TeV. This analysis\ntargets $Q \\to Wb$ decays where the $W$ boson decays leptonically. A veto on\nmassive large-radius jets is used to reject the dominant $t\\bar{t}$ background.\nThe reconstructed $Q$-candidate mass, ranging from 0.4 to 1.2 TeV, is used in\nthe search to discriminate signal from background processes. No significant\ndeviation from the Standard Model expectation is observed, and limits are set\non the $Q \\to Wb$ cross-section times branching ratio. The results are also\ninterpreted as limits on the $QWb$ coupling and the mixing with the Standard\nModel sector for a singlet $T$ quark or a $Y$ quark from a doublet. $T$ quarks\nwith masses below 0.95 TeV are excluded at 95% confidence level, assuming a\nunit coupling and a BR$(T\\rightarrow Wb) = 0.5$, whereas the expected limit is\n1.10 TeV.", "category": "hep-ex" }, { "text": "Re-discovery of the top quark at the LHC and first measurements: This paper describes the top quark physics measurements that can be performed\nwith the first LHC data in the ATLAS and CMS experiments.", "category": "hep-ex" }, { "text": "Amplitude analysis and branching-fraction measurement of $D_{s}^{+} \\to\n \u03c0^{+}\u03c0^{0}\u03b7^{\\prime}$: Using data collected with the BESIII detector in $e^+e^-$ collisions at\ncenter-of-mass energies between 4.178 and 4.226 GeV and corresponding to\n6.32~fb$^{-1}$ of integrated luminosity, we report the amplitude analysis and\nbranching-fraction measurement of the $D^+_s \\to \\pi^+ \\pi^0 \\eta^{\\prime}$\ndecay. We find that the dominant intermediate process is $D^+_s \\to\\rho^+\n\\eta^{\\prime}$ and the significances of other resonant and nonresonant\nprocesses are all less than $3\\sigma$. The upper limits on the branching\nfractions of $S$-wave and $P$-wave nonresonant components are set to $0.10\\%$\nand $0.74\\%$ at the $90\\%$ confidence level, respectively. In addition, the\nbranching fraction of the $D^+_s \\to \\pi^+ \\pi^0 \\eta^{\\prime}$ decay is\nmeasured to be $(6.15\\pm0.25(\\rm stat.)\\pm0.18(\\rm syst.))\\%$, which receives\nsignificant contribution only from $D_s^+\\to \\rho^+\\eta^{\\prime}$ according to\nthe amplitude analysis.", "category": "hep-ex" }, { "text": "Learning New Physics from Data -- a Symmetrized Approach: Thousands of person-years have been invested in searches for New Physics\n(NP), the majority of them motivated by theoretical considerations. Yet, no\nevidence of beyond the Standard Model (BSM) physics has been found. This\nsuggests that model-agnostic searches might be an important key to explore NP,\nand help discover unexpected phenomena which can inspire future theoretical\ndevelopments. A possible strategy for such searches is identifying asymmetries\nbetween data samples that are expected to be symmetric within the Standard\nModel (SM). We propose exploiting neural networks (NNs) to quickly fit and\nstatistically test the differences between two samples. Our method is based on\nan earlier work, originally designed for inferring the deviations of an\nobserved dataset from that of a much larger reference dataset. We present a\nsymmetric formalism, generalizing the original one; avoiding fine-tuning of the\nNN parameters and any constraints on the relative sizes of the samples. Our\nformalism could be used to detect small symmetry violations, extending the\ndiscovery potential of current and future particle physics experiments.", "category": "hep-ex" }, { "text": "Diffractive Structure Functions from the H1 and ZEUS Experiments at HERA: The cross section of inclusive diffractive process ep -> eXp was measured\nwithin a wide kinematic range in the H1 and ZEUS experiments at HERA. Results\nobtained by different experiments and methods are compatible within measurement\nuncertainties. The measurements were subjected to DGLAP next-to-leading order\nQCD global fits and the diffractive parton distribution functions (DPDFs) of\nthe proton were determined with noticeably reduced uncertainties due to very\nhigh precision of the data. The gluon density precision was much improved in\nfits which also included data on dijet production in diffractive DIS.\nPredictions based on the determined DPDFs are in agreement with the measured\ninclusive cross-section of diffractive dijet photoproduction and charm\nproduction in diffractive DIS at HERA. The longitudinal diffractive structure\nfunction $F^D_L$ was measured directly for the first time.", "category": "hep-ex" }, { "text": "Measurement Of Continuum Dimuon Production In 800-GeV/C Proton-Nucleon\n Collisions: Fermilab Experiment 866 has performed an absolute measurement of continuum\ndimuon (Drell-Yan) cross sections in 800-GeV/c $pp$ and $pd$ interactions.\nResults differential in the mass, Feynman-$x$ ($x_F$) and transverse momenta\n($p_T$) of the dimuon pairs are reported. These results represent the most\nextensive study of the Drell-Yan process to date, based on a data sample of\n175,000 dimuon events covering the widest range in kinematics yet achieved\n($4.2 \\leq M \\leq 16.85$ GeV and $-0.05 \\leq x_F \\leq 0.8$) with this level of\nprecision. The cross sections are primarily sensitive to the magnitude and\nshape of the light antiquark distributions ($\\bar{d}(x)$ and $\\bar{u}(x)$) in\nthe nucleon, but also provide important information on the valence quarks as\nwell as the gluons. They are in good agreement with other existing\nproton-induced Drell-Yan experiments. There is also general agreement between\nthe data and next-to-leading-order calculations based on various sets of parton\ndistribution functions. Differences between data and theory are examined, and\nthe potential impact of these data on future parameterizations of the parton\ndistributions are discussed.", "category": "hep-ex" }, { "text": "Search for magnetic monopoles and stable particles with high electric\n charges in 8 TeV $pp$ collisions with the ATLAS detector: A search for highly ionizing particles produced in proton-proton collisions\nat 8 TeV center-of-mass energy is performed by the ATLAS collaboration at the\nCERN Large Hadron Collider. The dataset used corresponds to an integrated\nluminosity of 7.0 fb$^{-1}$. A customized trigger significantly increases the\nsensitivity, permitting a search for such particles with charges and energies\nbeyond what was previously accessible. No events were found in the signal\nregion, leading to production cross section upper limits in the mass range\n200--2500 GeV for magnetic monopoles with magnetic charge in the range\n$0.5g_{D}<|g|<2.0g_{D}$, where $g_{D}$ is the Dirac charge, and for stable\nparticles with electric charge in the range $10<|z|<60$. Model-dependent limits\nare presented in given pair-production scenarios, and model-independent limits\nare presented in fiducial regions of particle energy and pseudorapidity.", "category": "hep-ex" }, { "text": "Measurement of the energy dependence of hadronic jet rates and the\n strong coupling alpha_s from the four-jet rate with the DELPHI detector at\n LEP: Hadronic events from the data collected with the DELPHI detector at LEP\nwithin the energy range from 89 GeV to 209 GeV are selected, their jet rates\nare determined and compared to predictions of four different event generators.\nOne of them is the recently developed APACIC++ generator which performs a\nmassive matrix element calculation matched to a parton shower followed by\nstring fragmentation. The four-jet rate is used to measure alpha_s in the\nnext-to-leading-order approximation yielding alpha_s(M_Z^2) = 0.1175 +/-\n0.0030. The running of alpha_s determined by using four-jet events has been\ntested. The logarithmic energy slope is measured to be d\\alpha_s^{-1} / d\\log\nE_{cm} = 1.14 +/- 0.36. Since the analysis is based on four-jet final states it\nrepresents an alternative approach to previous DELPHI alpha_s measurements\nusing event shape distributions.", "category": "hep-ex" }, { "text": "Top Quark Mass Measurement in the Lepton + Jets Channel Using a Matrix\n Element Method and in situ Jet Energy Calibration: A precision measurement of the top quark mass m_t is obtained using a sample\nof ttbar events from ppbar collisions at the Fermilab Tevatron with the CDF II\ndetector. Selected events require an electron or muon, large missing transverse\nenergy, and exactly four high-energy jets, at least one of which is tagged as\ncoming from a b quark. A likelihood is calculated using a matrix element method\nwith quasi-Monte Carlo integration taking into account finite detector\nresolution and jet mass effects. The event likelihood is a function of m_t and\na parameter DJES to calibrate the jet energy scale /in situ/. Using a total of\n1087 events, a value of m_t = 173.0 +/- 1.2 GeV/c^2 is measured.", "category": "hep-ex" }, { "text": "A Microsoft Word Font for Anti-Matter: One often wishes to quickly add a few overlined characters such as anti-B0 or\nanti-neutrino to a Microsoft Word document. Underlined characters are\nstraightforward but overlined characters require equation editor which makes\nsmall picture files. The font here allows one to directly add overlined English\nand the most used overlined Greek characters to Microsoft Word documents on\nApple Macintosh computers.", "category": "hep-ex" }, { "text": "Precise Branching Ratio Measurements of the Decays D0-->pi- pi+ pi0 and\n D0-->K- K+ pi0: Using 232 fb-1 of e+e- collision data recorded by the BaBar experiment, we\nmeasure the ratios of three-body Cabibbo-suppressed decay rates of the D^0\nmeson relative to that of the Cabibbo-favored decay:\n B(D0 --> pi- pi+ pi0)/ B(D0 --> K- pi+ pi0) = (10.59 +/- 0.06 +/-\n0.13).10^{-2} and B(D0 --> K- K+ pi0)/ B(D0 --> K- pi+ pi0) = (2.37 +/- 0.03\n+/- 0.04). 10^{-2}, where the errors are statistical and systematic\nrespectively. The precisions of these measurements are significantly better\nthan those of the current world average values.We note that the second result\ndiffers significantly from the current world average value. Using the PDG-2006\nvalue for D0 --> K- pi+ pi0 branching fraction, we obtain, B(D0 --> pi- pi+\npi0) = (1.493 +/- 0.008 +/- 0.018 +/- 0.053). 10^{-2}, B(D0 --> K- K+ pi0) =\n(0.334 +/- 0.004 +/- 0.006 +/- 0.012). 10^{-2}, where the errors are\nstatistical, systematic, and due to the uncertainty of B(D0 --> K- pi+ pi0).\nThe average squared matrix elements for both of the singly Cabibbo-suppressed\ndecays are roughly a factor of sin^2 \\theta_C smaller than that for the\nCabibbo-favored decay and are therefore, in contrast to the corresponding\ntwo-body modes, consistent with the naive expectations.", "category": "hep-ex" }, { "text": "Sleuth: A Quasi-Model-Independent Search Strategy for New Physics: How can we search for new physics when we only vaguely know what it should\nlook like? How can we perform an unbiased yet data-driven search? If we see\napparently anomalous events in our data, how can we quantify their\n\"interestingness\" a posteriori? We present an analysis strategy (Sleuth) that\nsimultaneously addresses each of these questions, and we demonstrate its\napplication to over thirty exclusive final states in data collected by D0 in\nRun I of the Fermilab Tevatron.", "category": "hep-ex" }, { "text": "Numerical Implementation of lepton-nucleus interactions and its effect\n on neutrino oscillation analysis: We discuss the implementation of the nuclear model based on realistic nuclear\nspectral functions in the GENIE neutrino interaction generator. Besides\nimproving on the Fermi gas description of the nuclear ground state, our scheme\ninvolves a new prescription for $Q^2$ selection, meant to efficiently enforce\nenergy momentum conservation. The results of our simulations, validated through\ncomparison to electron scattering data, have been obtained for a variety of\ntarget nuclei, ranging from carbon to argon, and cover the kinematical region\nin which quasi elastic scattering is the dominant reaction mechanism. We also\nanalyse the influence of the adopted nuclear model on the determination of\nneutrino oscillation parameters.", "category": "hep-ex" }, { "text": "Observation of $D^0\\to \u03c1^0\u03b3$ and search for $CP$ violation in\n radiative charm decays: We report the first observation of the radiative charm decay $D^0 \\to \\rho^0\n\\gamma$ and the first search for $CP$ violation in decays $D^0 \\to \\rho^0\n\\gamma$, $\\phi\\gamma$, and $\\overline{K}{}^{*0} \\gamma$, using a data sample of\n943 fb$^{-1}$ collected with the Belle detector at the KEKB asymmetric-energy\n$e^+e^-$ collider. The branching fraction is measured to be $\\mathcal{B}(D^0\n\\to \\rho^0 \\gamma)=(1.77 \\pm 0.30 \\pm 0.07) \\times 10^{-5}$, where the first\nuncertainty is statistical and the second is systematic. The obtained $CP$\nasymmetries, $\\mathcal{A}_{CP}(D^0 \\to \\rho^0 \\gamma)=+0.056 \\pm 0.152 \\pm\n0.006$, $\\mathcal{A}_{CP}(D^0 \\to \\phi \\gamma)=-0.094 \\pm 0.066 \\pm 0.001$, and\n$\\mathcal{A}_{CP}(D^0 \\to \\overline{K}{}^{*0} \\gamma)=-0.003 \\pm 0.020 \\pm\n0.000$, are consistent with no $CP$ violation. We also present an improved\nmeasurement of the branching fractions $\\mathcal{B}(D^0 \\to \\phi \\gamma)=(2.76\n\\pm 0.19 \\pm 0.10) \\times 10^{-5}$ and $\\mathcal{B}(D^0 \\to \\overline{K}{}^{*0}\n\\gamma)=(4.66 \\pm 0.21 \\pm 0.21) \\times 10^{-4}$.", "category": "hep-ex" }, { "text": "Future Atmospheric Neutrino Detectors: Future experiments focusing on atmospheric neutrino detection are reviewed.\nOne of the main goals of these experiments is the detection of an unambiguous\noscillation pattern (nu_mu reappearance) to prove the oscillation hypothesis.\nFurther goals include the discrimination of nu_mu - nu_tau and nu_mu -\nnu_sterile oscillations, and the detection of a potential small nu_mu - nu_e\ncontribution. The search for matter effects in three or more flavour\noscillations can be used to constrain hybrid oscillation models and potentially\nmeasure the sign of delta m^2. The detectors and measurement techniques\nproposed to achieve these goals are described, and their physics reach is\ndiscussed.", "category": "hep-ex" }, { "text": "Higgs Searches at LEP and at the Tevatron: After years of efforts to push the LEP performance to, and indeed beyond, the\nlimits of what had been believed possible, hints of signal of a Higgs boson at\n115GeV/c2 appeared in June 2000, were confirmed in September, and confirmed\nagain in November. Spending an additional six-month period with LEP would have\ngiven the unambiguous opportunity of a fundamental discovery. Instead, this\npossibilty was handed over to the Tevatron, for which at least si more years\nwill be needed to confirm the existence of a Higgs boson around 115GeV/c2. The\nupgrades performed at LEP and needed at the Tevatron, together with the physics\noutcomes, are briefly mentioned in turn.", "category": "hep-ex" }, { "text": "Limits on Interactions between Weakly Interacting Massive Particles and\n Nucleons Obtained with NaI(Tl) crystal Detectors: Limits on the cross section for weakly interacting massive particles (WIMPs)\nscattering off nucleons in the NaI(Tl) detectors at the Yangyang Underground\nLaboratory are obtained with a 2967.4 kg*day data exposure. Nuclei recoiling\nare identified by the pulse shape of scintillating photon signals. Data are\nconsistent with no nuclear recoil hypothesis, and 90% confidence level upper\nlimits are set. These limits partially exclude the DAMA/LIBRA region of\nWIMP-sodium interaction with the same NaI(Tl) target detector. This 90%\nconfidence level upper limit on WIMP-nucleon spin-independent cross section is\n3.26*10^-4 pb for a WIMP mass at 10 GeV/c^2.", "category": "hep-ex" }, { "text": "Measurements of the top quark mass and decay width with the D0 detector: The top quark discovery in 1995 at Fermilab is one of the major proofs of the\nstandard model (SM). Due to its unique place in SM, the top quark is an\nimportant particle for testing the theory and probing for new physics. This\narticle presents most recent measurements of top quark properties from the D0\ndetector. In particular, the measurement of the top quark mass, the top antitop\nmass difference and the top quark decay width.", "category": "hep-ex" }, { "text": "Taiwan Axion Search Experiment with Haloscope: CD102 Analysis Details: This paper presents the analysis of the data acquired during the first\nphysics run of the Taiwan Axion Search Experiment with Haloscope (TASEH), a\nsearch for axions using a microwave cavity at frequencies between 4.70750 and\n4.79815 GHz. The data were collected from October 13, 2021 to November 15,\n2021, and are referred to as the CD102 data. The analysis of the TASEH CD102\ndata excludes models with the axion-two-photon coupling $|g_{a\\gamma\\gamma}|\n\\gtrsim 8.2\\times 10^{-14}$ GeV$^{-1}$, a factor of eleven above the benchmark\nKSVZ model for the mass range 19.4687 < ma < 19.8436 $\\mu$eV.", "category": "hep-ex" }, { "text": "Observation of Single Top Quark Production at D0: This paper presents the observation of the electroweak production of single\ntop quarks in the D0 detector at the Fermilab Tevatron Collider at a\ncenter-of-mass energy of 1.96 TeV. Events containing an isolated electron or\nmuon and missing transverse energy, together with jets originating from the\nfragmentation of b quarks are used to measure a cross section for single top\nquark production of sigma(ppbar -> tb + X, tqb + X) = 3.94 +- 0.88 pb. The\nprobability to measure a cross section at this value or higher in the absence\nof signal is 2.5X10^-7, corresponding to a 5.0 standard deviation significance.", "category": "hep-ex" }, { "text": "Search for the rare decays $J/\u03c8\\to D_s^-\u03c1^+$ and $J/\u03c8\\to\n \\overline{D}{}^0\\overline{K}{}^{\\ast0}$: A search for the rare decays of $J/\\psi \\to D_s^-\\rho^+ + c.c.$ and $J/\\psi\n\\to \\overline{D}{}^0\\overline{K}{}^{\\ast0} + c.c.$ is performed with a data\nsample of 225.3 million $J/\\psi$ events collected with the BESIII detector. No\nevident signal is observed. Upper limits on the branching fractions are\ndetermined to be $\\mathcal{B}(J/\\psi \\to D_s^-\\rho^+ + c.c.) < 1.3 \\times\n10^{-5}$ and $\\mathcal{B}(J/\\psi \\to \\overline{D}{}^0\\overline{K}{}^{\\ast0} +\nc.c.) < 2.5 \\times 10^{-6}$ at the $90\\%$ confidence level.", "category": "hep-ex" }, { "text": "The onset of the anomalous J/psi suppression in Pb-Pb collisions at the\n CERN SPS: The J/psi suppression observed by the NA50 experiment is one of the most\nstriking signatures for quark gluon plasma formation in Pb-Pb collisions at 158\nAGeV. The J/psi production has been studied as a function of the centrality of\nthe collision estimated via the forward energy EZDC released in a zero degree\ncalorimeter (ZDC). The study of the correlation between the number of\nparticipant nucleons in the collisions, Npart, and EZDC allows to check whether\nthe J/psi suppression pattern vs. EZDC is compatible with a sudden J/psi\nsuppression mechanism expressed as a function of Npart.", "category": "hep-ex" }, { "text": "RFQD - a Decelerating Radio Frequency Quadrupole for the CERN Antiproton\n Facility: The RFQD is designed to decelerate antiprotons of momentum 100 MeV/c (kinetic\nenergy 5.33MeV)down to a kinetic energy variable between ~10 keV and 120 keV.\nInside the RFQ body, at ground potential, the rf structure of the four-rod type\nis mounted on insulating supports. It can be biased between plus/minus 60 kV dc\nto achieve the continuous adjustment of output energy required by the ASACUSA\nexperiment at the CERN Antiproton Decelerator AD. The different parts of the\nsystem are described and the present status reported.", "category": "hep-ex" }, { "text": "Evidence for Narrow S=+1 Baryon Resonance in Photo-production from\n Neutron: The gamma n -> K+ K- n reaction on 12C has been studied by measuring both K+\nand K- at forward angles. A sharp baryon resonance peak was observed at 1.54 +-\n0.01 GeV with a width smaller than 25 MeV and a Gaussian significance of 4.6\nsigma. The strangeness quantum number (S) of the baryon resonance is +1. It can\nbe interpreted as a molecular meson-baryon resonance or alternatively as an\nexotic 5-quark state (uudd{s_bar}) that decays into a K+ and a neutron. The\nresonance is consistent with the lowest member of an anti-decuplet of baryons\npredicted by the chiral soliton model.", "category": "hep-ex" }, { "text": "Study of the rare $B_s^0$ and $B^0$ decays into the\n $\u03c0^+\u03c0^-\u03bc^+\u03bc^-$ final state: A search for the rare decays $B_s^0 \\to \\pi^+\\pi^-\\mu^+\\mu^-$ and $B^0 \\to\n\\pi^+\\pi^-\\mu^+\\mu^-$ is performed in a data set corresponding to an integrated\nluminosity of 3.0 fb$^{-1}$ collected by the LHCb detector in proton-proton\ncollisions at centre-of-mass energies of 7 and 8 TeV. Decay candidates with\npion pairs that have invariant mass in the range 0.5-1.3 GeV/$c^2$ and with\nmuon pairs that do not originate from a resonance are considered. The first\nobservation of the decay $B_s^0 \\to \\pi^+\\pi^-\\mu^+\\mu^-$ and the first\nevidence of the decay $B^0 \\to \\pi^+\\pi^-\\mu^+\\mu^-$ are obtained and the\nbranching fractions, restricted to the dipion-mass range considered, are\nmeasured to be $\\mathcal{B}(B_s^0 \\to \\pi^+\\pi^-\\mu^+\\mu^-)=(8.6\\pm 1.5\\,({\\rm\nstat}) \\pm 0.7\\,({\\rm syst})\\pm 0.7\\,({\\rm norm}))\\times 10^{-8}$ and\n$\\mathcal{B}(B^0 \\to \\pi^+\\pi^-\\mu^+\\mu^-)=(2.11\\pm 0.51\\,({\\rm stat}) \\pm\n0.15\\,({\\rm syst})\\pm 0.16\\,({\\rm norm}) )\\times 10^{-8}$, where the third\nuncertainty is due to the branching fraction of the decay $B^0\\to J/\\psi(\\to\n\\mu^+\\mu^-)K^*(890)^0(\\to K^+\\pi^-)$, used as a normalisation.", "category": "hep-ex" }, { "text": "Particle Physics Aspects of Antihydrogen Studies with ALPHA at CERN: We discuss aspects of antihydrogen studies, that relate to particle physics\nideas and techniques, within the context of the ALPHA experiment at CERN's\nAntiproton Decelerator facility. We review the fundamental physics motivations\nfor antihydrogen studies, and their potential physics reach. We argue that\ninitial spectroscopy measurements, once antihydrogen is trapped, could provide\ncompetitive tests of CPT, possibly probing physics at the Planck Scale. We\ndiscuss some of the particle detection techniques used in ALPHA. Preliminary\nresults from commissioning studies of a partial system of the ALPHA Si vertex\ndetector are presented, the results of which highlight the power of\nannihilation vertex detection capability in antihydrogen studies.", "category": "hep-ex" }, { "text": "N* and Meson Resonances in J/psi decays: Over sixty million J/psi events have been collected by the BES Collaboration\nat the Beijing Electron-Positron Collider (BEPC). J/psi decays provide an\nexcellent place for studying excited nucleons and hyperons -- N*, $\\Lambda^*$,\n$\\Sigma^*$ and $\\Xi^*$ resonances, as well as meson resonances, including\npossible glueballs and hybrids. Physics objectives, recent results and future\nprospects of light hadron spectroscopy at BEPC are presented.", "category": "hep-ex" }, { "text": "Search for b --> u Transitions in B^{+-} --> [K^{-+} pi^{+-} pi0]_D\n K^{+-} Decays: We present a study of the decays B^{+-} --> D K^{+-} with D mesons\nreconstructed in the K+pi-pi0 or K-pi+pi0 final states, where D indicates a D0\nor a anti-D0 meson. Using a sample of 474 million BBbar pairs collected with\nthe BaBar detector at the PEP-II asymmetric-energy e+e- collider at SLAC we\nobtain R^{+} = (5^{+12}_{-10}(stat) ^{+2}_{-4}(syst))\\times10^{-3} and R^{-} =\n(12^{+12}_{-10}(stat) ^{+3}_{-5}(syst))\\times10^{-3}, from which we extract the\nupper limits at 90% probability: R^+<23\\times10^{-3} and R^-<29\\times10^{-3}.\nUsing these measurements, we obtain an upper limit for the ratio rB of the\nmagnitudes of the b --> u and b --> c amplitudes r_B<0.13 at 90% probability.", "category": "hep-ex" }, { "text": "First measurement of the cross section for $\u03bd_\u03bc$ and $\\bar\u03bd_\u03bc$\n induced single charged pion production on argon using ArgoNeuT: We report on the first cross section measurement of charged-current single\ncharged pion production by neutrinos and antineutrinos on argon. This analysis\nwas performed using the ArgoNeuT detector exposed to the NuMI beam at Fermilab.\nThe measurements are presented as functions of muon momentum, muon angle, pion\nangle, and angle between muon and pion. The flux-averaged cross sections are\nmeasured to be $2.7\\pm0.5(stat)\\pm0.5(syst) \\times 10^{-37}\n\\textrm{cm}^{2}/\\textrm{Ar}$ for neutrinos at a mean energy of 9.6 GeV and\n$8.4\\pm0.9(stat)^{+1.0}_{-0.8}(syst) \\times 10^{-38}\n\\textrm{cm}^{2}/\\textrm{Ar}$ for antineutrinos at a mean energy of 3.6 GeV with\nthe charged pion momentum above 100 MeV/$c$. The results are compared with\nseveral model predictions.", "category": "hep-ex" }, { "text": "Short-Range and Long-Range Correlations in DIS at HERA: Correlations in deep-inelastic scattering at HERA are investigated in order\nto test perturbative QCD and quark fragmentation universality. Two-particle\ncorrelations at small angular separations are measured in the Breit frame and\ncompared to e+e- collisions. Also presented are the correlations between the\ncurrent and target regions of the Breit frame.", "category": "hep-ex" }, { "text": "The Double Chooz reactor neutrino experiment: The Double Chooz reactor neutrino experiment will be the next detector to\nsearch for a non vanishing theta13 mixing angle with unprecedented sensitivity,\nwhich might open the way to unveiling CP violation in the leptonic sector. The\nmeasurement of this angle will be based in a precise comparison of the\nantineutrino spectrum at two identical detectors located at different distances\nfrom the Chooz nuclear reactor cores in France. Double Chooz is particularly\nattractive because of its capability to measure sin2(2theta13) to 3 sigmas if\nsin2(2theta13) > 0.05 or to exclude sin2(2theta13) down to 0.03 at 90% C.L. for\nDm2 = 2.5 x 10-3 eV2 in three years of data taking with both detectors. The\nconstruction of the far detector starts in 2008 and the first neutrino results\nare expected in 2009. The current status of the experiment, its physics\npotential and design and expected performance of the detector are reviewed.", "category": "hep-ex" }, { "text": "Search for new phenomena with the monojet and missing transverse\n momentum signature using the ATLAS detector in sqrt(s) = 7 TeV proton-proton\n collisions: A search for new phenomena in events featuring a high energy jet and large\nmissing transverse momentum in proton-proton collisions at sqrt(s) = 7 TeV is\npresented using a dataset corresponding to an integrated luminosity of 33 pb^-1\nrecorded with the ATLAS detector at the Large Hadron Collider. The number of\nobserved events is consistent with the Standard Model prediction and this\nresult is interpreted in terms of limits on a model of Large Extra Dimensions.", "category": "hep-ex" }, { "text": "Observation of B- to pbar Lambda D0 at Belle: We study B- meson decays to pbar Lambda D(*)0 final states using a sample of\n657 * 10^6 B Bbar events collected at the Upsilon(4S) resonance with the Belle\ndetector at the KEKB asymmetric-energy e+ e- collider. The observed branching\nfraction for B- to pbar Lambda D0 is (1.43^ +0.28_-0.25 +- 0.18)*10^-5. with a\nsignificance of 8.1 standard deviations, where the uncertainties are\nstatistical and systematic, respectively. Most of the signal events have the\npbarLambda mass peaking near threshold. No significant signal is observed for\nB- to pbar Lambda D*0 and the corresponding upper limit on the branching\nfraction is 4.8 * 10^-5 at the 90% confidence level.", "category": "hep-ex" }, { "text": "Key4hep: Progress Report on Integrations: Detector studies for future experiments rely on advanced software tools to\nestimate performance and optimize their design and technology choices. The\nKey4hep project provides a flexible turnkey solution for the full experiment\nlife-cycle based on established community tools such as ROOT, Geant4, DD4hep,\nGaudi, podio and spack. Members of the CEPC, CLIC, EIC, FCC, and ILC\ncommunities have joined to develop this framework and have merged, or are in\nthe progress of merging, their respective software environments into the\nKey4hep stack. These proceedings will give an overview over the recent progress\nin the Key4hep project: covering the developments towards adaptation of\nstate-of-the-art tools for simulation (DD4hep, Gaussino), track and calorimeter\nreconstruction (ACTS, CLUE), particle flow (PandoraPFA), analysis via\nRDataFrame, and visualization with Phoenix, as well as tools for testing and\nvalidation.", "category": "hep-ex" }, { "text": "On the possibility to use ATLAS and CMS detectors for neutrino physics: Energetic primary cosmic rays entering the Earth's atmosphere generate flux\nof secondary particles including neutrinos. Muon neutrinos passed through the\nEarth and produced muons via the charged current reaction can be registered by\nexperimental setups intended for the measurements with colliding beams. Due to\nlarge geometrical size and advanced muon detecting system such detectors as\nATLAS and CMS on LHC have chance to contribute also into the neutrino physics.\nThe estimation of possible rates of up-going muons produced by neutrinos is\ngiven.", "category": "hep-ex" }, { "text": "Observation of single top quark production in association with a Z boson\n in proton-proton collisions at $\\sqrt{s} =$ 13 TeV: The observation of single top quark production in association with a Z boson\nand a quark (tZq) is reported. Events from proton-proton collisions at a\ncenter-of-mass energy of 13 TeV containing three charged leptons (either\nelectrons or muons) and at least two jets are analyzed. The data were collected\nwith the CMS detector in 2016 and 2017, and correspond to an integrated\nluminosity of 77.4 fb$^{-1}$. The increased integrated luminosity, a\nmultivariate lepton identification, and a redesigned analysis strategy improve\nsignificantly the sensitivity of the analysis compared to previous searches for\ntZq production. The tZq signal is observed with a significance well over five\nstandard deviations. The measured tZq production cross section is $\\sigma$(pp\n$\\to$ tZq $\\to$ t$\\ell^{+} \\ell^{-}$q) = 111 $\\pm$ 13 (stat) $ _{-9}^{+11}$\n(syst) fb, for dilepton invariant masses above 30 GeV, in agreement with the\nstandard model expectation.", "category": "hep-ex" }, { "text": "Search for B+ -> l+ nu gamma decays with hadronic tagging using the full\n Belle data sample: We search for the decay B+ -> l+ nu gamma with l+ = e+ or mu+ using the full\nBelle data set of 772 x 10^6 BBbar pairs, collected at the Y(4S) resonance with\nthe Belle detector at the KEKB asymmetric-energy e+e- collider. We reconstruct\none B meson in a hadronic decay mode and search for the B+ -> l+ nu gamma decay\nin the remainder of the event. We observe no significant signal within the\nphase space of E_gamma^sig > 1 GeV and obtain upper limits of BR(B+ -> e+ nu\ngamma) < 6.1 x 10^-6, BR(B+ -> mu+ nu gamma) < 3.4 x 10^-6, and BR(B+ -> l+ nu\ngamma) < 3.5 x 10^-6 at 90 % credibility level.", "category": "hep-ex" }, { "text": "Standard Model Physics Results from LEP2: At LEP2 many Standard Model predictions are tested up to centre-of-mass\nenergies of 209 GeV. Fermion pair production cross sections and asymmetries\nagree well with the theoretical expectation over the entire energy range. The\nmeasurements are used to determine the gamma/Z interference and to search for\ncontact interactions up to 20 TeV. The cross sections for single-W, ZZ and W+W-\nproduction agree well with the expectations. The branching fractions of the W\nboson into hadrons and leptons are determined as well as the CKM matrix element\n|V_{cs}|. Precise measurements of the W mass and width are presented yielding\nMW=80.427+-0.046 GeV and GammaW=2.12=_0.11 GeV. All electroweak data are very\nconsistent with the Standard Model predictions. In a combined fit using the\nrecent value of Delta alpha_{had}^(5)(s) the mass of the Higgs boson is\nconstrained to MH=88^{+60}_{-37} GeV.", "category": "hep-ex" }, { "text": "Transition to the region of central collisions and critical phenomena: The experimental results on the relation between the processes of total\ndisintegration of nuclei (or the cases with central collisions) and the\ncritical phenomena which can occur in the region of high degree of nuclear\ndisintegration or of collision centrality are discussed.", "category": "hep-ex" }, { "text": "Enhanced NeUtrino BEams from kaon Tagging (ENUBET): ENUBET aims at demonstrating the feasibility of a \"monitored\" neutrino beam,\nin which the absolute normalization of the neutrino flux can be constrained at\nthe 1% level. The $\\nu_e$ flux is determined by monitoring large-angle $e^+$\nfrom $K_{e3}$ decays in a 40 m long instrumented decay tunnel. The $\\nu_\\mu$\nflux is provided by muons produced by decays of $K$ and $\\pi$. Being a narrow\nband beam ($p=8.5$ GeV/$c$ $\\pm$ 10%), the transverse position of the\ninteraction at the detector can be exploited to determine a priori the neutrino\nenergy spectrum without relying on the final state reconstruction (\"narrow band\noff-axis technique\"). Lepton monitoring and narrow band off-axis energy\nreconstruction can be implemented in a single facility based on standard\naccelerator technologies for a new generation of high precision $\\nu_e$ and\n$\\nu_\\mu$ cross section measurements at the GeV scale and for precision\nsearches of physics beyond the standard 3$\\nu$ paradigm. In 2019-2022 ENUBET\nhas devised the first end-to-end simulation of the facility and demonstrated\nthat the precision goals can be achieved in $\\sim$ 3 years of data taking\nemploying neutrino detectors of moderate mass (ICARUS at FNAL, ProtoDUNE at\nCERN). The technology of a monitored beam has been proven to be feasible and\ncost-effective, and the complexity does not exceed significantly the one of a\nconventional short-baseline beam. The Snowmass 2021 DPF Community Planning\nExercise is thus timely for the consideration of monitored neutrino beams\nhosting the next generation of cross section experiments. The ENUBET results\nwill play an important role in the systematic reduction programme of future\nlong baseline experiments, thus enhancing the physics reach of DUNE and\nHyper-Kamiokande. In this document, we summarize the ENUBET design, physics\nperformance and opportunities for its implementation in a timescale comparable\nwith DUNE.", "category": "hep-ex" }, { "text": "Rare decay searches at CDF: In the last decade the CDF experiment at the Tevatron clearly demonstrated\nthat it is possible to study extensively heavy flavour physics in hadron\ncollisions and achieve remarkable results, competitive and complementary to\n$B$-factories. In this paper we report on the indirect searches for physics\nbeyond the standard model via measurements of rare $b$-hadron decays. The final\nlimits, based on the analysis of the full CDF data set, on the branching\nfraction of the $B^0_{(s)}$ decay into a pair of muons are presented and\ndiscussed. Moreover we review the latest measurements, with 6.8 fb$^{-1}$ of\ncollected data, of the total and differential branching fractions and angular\nobservables of rare $b$-hadron decays proceeding via the flavour-changing\nneutral-current process $b \\rightarrow s \\mu^+ \\mu^-$. PACS numbers: 13.20.He,\n13.30.-a, 12.15.Mn", "category": "hep-ex" }, { "text": "Search for neutral Higgs bosons in multi-$b$-jet events in $p\\bar{p}$\n collisions at $\\sqrt{s} = 1.96$ TeV: Data recorded by the D0 experiment at the Fermilab Tevatron Collider are\nanalyzed to search for neutral Higgs bosons produced in association with $b$\nquarks. This production mode can be enhanced in the minimal supersymmetric\nstandard model (MSSM). The search is performed in the three $b$ quark channel\nusing multijet triggered events corresponding to an integrated luminosity of $1\n\\mathrm{fb}^{-1}$. No statistically significant excess of events with respect\nto the predicted background is observed and limits are set in the MSSM\nparameter space.", "category": "hep-ex" }, { "text": "Single Phonon Detection for Dark Matter via Quantum Evaporation and\n Sensing of $^3$Helium: Dark matter is five times more abundant than ordinary visible matter in our\nUniverse. While laboratory searches hunting for dark matter have traditionally\nfocused on the electroweak scale, theories of low mass hidden sectors motivate\nnew detection techniques. Extending these searches to lower mass ranges, well\nbelow 1 GeV/c$^2$, poses new challenges as rare interactions with standard\nmodel matter transfer progressively less energy to electrons and nuclei in\ndetectors. Here, we propose an approach based on phonon-assisted quantum\nevaporation combined with quantum sensors for detection of desorption events\nvia tracking of spin coherence. The intent of our proposed dark matter sensors\nis to extend the parameter space to energy transfers in rare interactions to as\nlow as a few meV for detection of dark matter particles in the keV/c$^2$ mass\nrange.", "category": "hep-ex" }, { "text": "Measurements of differential $t\\bar{t}$ production cross sections at CMS: An overview of recent measurements of differential top quark pair production\ncross sections performed by the CMS experiment at the LHC is presented.\nMeasurements at different proton-proton center-of-mass energies are available\nusing the dilepton, lepton+jets, and all-jets decay channels of the top quark.\nIn addition to the measurements of parton-level top quarks, many measurements\nat particle level in an experimental accessible phase space are now available.\nFor these results the dependence on theoretical extrapolations is reduced. A\ncommon observation of all measurements is a softer transverse momentum of the\ntop quark than predicted by state of the art standard model calculations.\nHowever, new calculations with NNLO QCD and NLO electro-weak precision show an\nimproved agreement.", "category": "hep-ex" }, { "text": "Measurement of the high-energy all-flavor neutrino-nucleon cross section\n with IceCube: The flux of high-energy neutrinos passing through the Earth is attenuated due\nto their interactions with matter. The interaction rate is modulated by the\nneutrino interaction cross section and affects the flux arriving at the IceCube\nNeutrino Observatory, a cubic-kilometer neutrino detector embedded in the\nAntarctic ice sheet. We present a measurement of the neutrino cross section\nbetween 60 TeV and 10 PeV using the high-energy starting events (HESE) sample\nfrom IceCube with 7.5 years of data. The result is binned in neutrino energy\nand obtained using both Bayesian and frequentist statistics. We find it\ncompatible with predictions from the Standard Model. Flavor information is\nexplicitly included through updated morphology classifiers, proxies for the the\nthree neutrino flavors. This is the first such measurement to use the three\nmorphologies as observables and the first to account for neutrinos from tau\ndecay.", "category": "hep-ex" }, { "text": "Heavy Quark Production and Decay: t, b, and onia: This paper summarizes a variety of recent results on heavy quark production\nand decay. Considerable progress has been made by CDF and D0 in measuring top\nquark production and decay properties. The top quark mass been measured with an\nuncertainty that is less than 3%, a relative precision that is better than has\nbeen achieved for other quarks. Measurements of the top production and decay\nproperties are consistent with the Standard Model predictions, but are\ngenerally limited in precision by the small number of top quark events in the\npresent data samples. ALEPH and CLEO have measured the branching ratio for the\nflavor changing neutral current decay b->s gamma and find good agreement with\nthe Standard Model. Measurements of b-quark production cross sections in ppbar\ncollisions by CDF and D0 and in ep collisions by H1 continue to show\ndiscrepancies between theory and experiment. CDF and DELPHI have measured the\nb-quark fragmentation fractions with better accuracy than previous\nmeasurements. Finally, measurements of charmonium production by D0, E771, and\nL3 are consistent with predictions of the color octet model.", "category": "hep-ex" }, { "text": "Search for pair production of heavy vector-like quarks decaying into\n high-$p_T$ $W$ bosons and top quarks in the lepton-plus-jets final state in\n $pp$ collisions at $\\sqrt{s}$=13 TeV with the ATLAS detector: A search is presented for the pair production of heavy vector-like $B$\nquarks, primarily targeting $B$ quark decays into a $W$ boson and a top quark.\nThe search is based on $36.1$ $fb^{-1}$ of $pp$ collisions at $\\sqrt{s}$ = 13\nTeV recorded in 2015 and 2016 with the ATLAS detector at the CERN Large Hadron\nCollider. Data are analysed in the lepton-plus-jets final state, characterised\nby a high-transverse-momentum isolated electron or muon, large missing\ntransverse momentum, and multiple jets, of which at least one is $b$-tagged. No\nsignificant deviation from the Standard Model expectation is observed. The 95%\nconfidence level lower limit on the $B$ mass is 1350 GeV assuming a 100%\nbranching ratio to $Wt$. In the SU(2) singlet scenario, the lower mass limit is\n1170 GeV. This search is also sensitive to a heavy vector-like $B$ quark\ndecaying into other final states ($Zb$ and $Hb$) and thus mass limits on $B$\nproduction are set as a function of the decay branching ratios. The 100%\nbranching ratio limits are found to be also applicable to heavy vector-like $X$\nproduction, with charge $+$5/3, that decay into $Wt$.", "category": "hep-ex" }, { "text": "Rare decay searches at CDF: In the last decade the CDF experiment at the Tevatron clearly demonstrated\nthat it is possible to study extensively heavy flavour physics in hadron\ncollisions and achieve remarkable results, competitive and complementary to\n$B$-factories. In this paper we report on the indirect searches for physics\nbeyond the standard model via measurements of rare $b$-hadron decays. The final\nlimits, based on the analysis of the full CDF data set, on the branching\nfraction of the $B^0_{(s)}$ decay into a pair of muons are presented and\ndiscussed. Moreover we review the latest measurements, with 6.8 fb$^{-1}$ of\ncollected data, of the total and differential branching fractions and angular\nobservables of rare $b$-hadron decays proceeding via the flavour-changing\nneutral-current process $b \\rightarrow s \\mu^+ \\mu^-$. PACS numbers: 13.20.He,\n13.30.-a, 12.15.Mn", "category": "hep-ex" }, { "text": "Confirmation of a charged charmoniumlike state $Z_c(3885)^{\\mp}$ in\n $e^+e^-\\to\u03c0^{\\pm}(D\\bar{D}^*)^\\mp$ with double $D$ tag: We present a study of the process $e^+e^-\\to\\pi^{\\pm}(D\\bar{D}^*)^{\\mp}$\nusing data samples of 1092~pb$^{-1}$ at $\\sqrt{s}=4.23$~GeV and 826~pb$^{-1}$\nat $\\sqrt{s}=4.26$~GeV collected with the BESIII detector at the BEPCII storage\nring. With full reconstruction of the $D$ meson pair and the bachelor\n$\\pi^{\\pm}$ in the final state, we confirm the existence of the charged\nstructure $Z_c(3885)^{\\mp}$ in the $(D\\bar{D}^*)^{\\mp}$ system in the two\nisospin processes $e^+e^-\\to\\pi^+D^0D^{*-}$ and $e^+e^-\\to\\pi^+D^-D^{*0}$. By\nperforming a simultaneous fit, the statistical significance of $Zc(3885)^{\\mp}$\nsignal is determined to be greater than 10$\\sigma$, and its pole mass and width\nare measured to be\n$M_{\\rm{pole}}$=(3881.7$\\pm$1.6(stat.)$\\pm$1.6(syst.))~MeV/$c^2$ and\n$\\Gamma_{\\rm{pole}}$=(26.6$\\pm$2.0(stat.)$\\pm$2.1(syst.))~MeV, respectively.\nThe Born cross section times the $(D\\bar{D}^*)^{\\mp}$ branching fraction\n($\\sigma(e^+e^-\\to\\pi^{\\pm}Z_{c}(3885)^{\\mp}) \\times\nBr(Z_{c}(3885)^{\\mp}\\to(D\\bar{D}^*)^{\\mp})$) is measured to be\n$(141.6\\pm7.9(\\text{stat.})\\pm12.3(\\text{syst.}))~\\text{pb}$ at\n$\\sqrt{s}=4.23$~GeV and\n$(108.4\\pm6.9(\\text{stat.})\\pm8.8(\\text{syst.}))~\\text{pb}$ at\n$\\sqrt{s}=4.26$~GeV. The polar angular distribution of the\n$\\pi^{\\pm}$-$Z_c(3885)^{\\mp}$ system is consistent with the expectation of a\nquantum number assignment of $J^P=1^+$ for $Z_c(3885)^{\\mp}$.", "category": "hep-ex" }, { "text": "Probing the quantum interference between singly and doubly resonant\n top-quark production in $pp$ collisions at $\\sqrt{s}=13$ TeV with the ATLAS\n detector: This Letter presents a normalized differential cross-section measurement in a\nfiducial phase-space region where interference effects between top-quark pair\nproduction and associated production of a single top quark with a $W$ boson and\na $b$-quark are significant. Events with exactly two leptons ($ee$, $\\mu\\mu$,\nor $e\\mu$) and two $b$-tagged jets that satisfy a multi-particle invariant mass\nrequirement are selected from $36.1$ fb$^{-1}$ of proton-proton collision data\ntaken at $\\sqrt{s}=13$ TeV with the ATLAS detector at the LHC in 2015 and 2016.\nThe results are compared with predictions from simulations using various\nstrategies for the interference. The standard prescriptions for interference\nmodeling are significantly different from each other but are within $2\\sigma$\nof the data. State-of-the-art predictions that naturally incorporate\ninterference effects provide the best description of the data in the measured\nregion of phase space most sensitive to these effects. These results provide an\nimportant constraint on interference models and will guide future model\ndevelopment and tuning.", "category": "hep-ex" }, { "text": "Measurement of the top pair invariant mass distribution at 7 TeV and\n search for new physics: An overview of searches for new physics in the ttbar sample from the CMS\nCollaboration is presented with data collected at the Large Hadron Collider at\nsqrt(s) = 7 TeV. There are several searches presented, including same-sign\ndilepton signatures, semileptonic signatures, and all-hadronic signatures, the\nlatter of which uses advanced jet reconstruction techniques.", "category": "hep-ex" }, { "text": "Observation of the phi to pi+pi-pi+pi- Decay: Using 11.6 pb^{-1} of data collected in the energy range 0.984--1.06 GeV by\nCMD-2 at VEPP-2M, the cross section of the reaction e+e- to pi+pi-pi+pi- has\nbeen studied. For the first time an interference pattern was observed in the\nenergy dependence of the cross section near the phi meson. The branching ratio\nof the phi to pi+pi-pi+pi- decay double suppressed by the G-parity and OZI rule\nis measured Br(phi to pi+pi-pi+pi-) = (3.93 +- 1.74 +- 2.14) \\cdot 10^{-6}. The\nupper limits have been placed for the decays phi to pi+pi-pi+pi-pi0 and phi to\neta pi+pi-\n Br(phi to pi+pi-pi+pi-pi0) < 4.6 \\cdot 10^{-6} 90% CL,\n Br(phi to eta pi+pi-) < 1.8 \\cdot 10^{-5} 90% CL.", "category": "hep-ex" }, { "text": "Detection of Cascades induced by Atmospheric Neutrinos in the 79-string\n IceCube Detector: Neutrino production and oscillation physics can be studied by utilizing the\nvery high flux of atmospheric neutrinos observed with IceCube. In a Cherenkov\nmedium such as ice, atmospheric muon neutrino interactions create tracks while\ncascades (showers) are produced by atmospheric electron neutrinos and by\nneutral current interactions of all flavors. We present the first detection of\natmospheric neutrino-induced cascades at energies between 30 GeV and 10 TeV\nusing the DeepCore array of the IceCube detector. Using 281 days of data, 1029\nevents are observed with 59% predicted to be cascades.", "category": "hep-ex" }, { "text": "Search for supersymmetry, extra dimensions and exotic phenomena at LEP: The latest results on searches for supersymmetry, extra dimensions and exotic\nphenomena from the LEP collaborations are presented. No significant signal-like\nexcess is observed in the data. The results are interpreted in various models\nand robust constraints are placed.", "category": "hep-ex" }, { "text": "Rapidity-Rank Structure of p pbar Pairs in Hadronic Z0 Decays: The rapidity-rank structure of p pbar pairs is used to analyze the mechanism\nof baryon production in hadronic Z0 decay. The relative occurrence of the\nrapidity-ordered configuration p M pbar, where M is a meson, and that of p pbar\nadjacent pairs is compared. The data are found to be consistent with\npredictions from a mechanism producing adjacent-rank p pbar pairs, without\nrequiring `string-ordered' p M pbar configurations. An upper limit of 15% at\n90% confidence is determined for the p M pbar contribution.", "category": "hep-ex" }, { "text": "Search for dark matter-nucleon interactions via Migdal effect with\n DarkSide-50: Dark matter elastic scattering off nuclei can result in the excitation and\nionization of the recoiling atom through the so-called Migdal effect. The\nenergy deposition from the ionization electron adds to the energy deposited by\nthe recoiling nuclear system and allows for the detection of interactions of\nsub-GeV/c$^2$ mass dark matter. We present new constraints for sub-GeV/c$^2$\ndark matter using the dual-phase liquid argon time projection chamber of the\nDarkSide-50 experiment with an exposure of (12306 $\\pm$ 184) kg d. The analysis\nis based on the ionization signal alone and significantly enhances the\nsensitivity of DarkSide-50, enabling sensitivity to dark matter with masses\ndown to 40 MeV/c$^2$. Furthermore, it sets the most stringent upper limit on\nthe spin independent dark matter nucleon cross section for masses below $3.6$\nGeV/c$^2$.", "category": "hep-ex" }, { "text": "A New Measurement of eta_b(1S) From Upsilon(3S) Radiative Decay at CLEO: Using CLEO data, we report on the confirmation of the eta_b(1S0) ground state\nof bottomonium in the radiative decay Upsilon(3S) -> gamma eta_b. We determine\nits mass to be M(eta_b) = 9391.8 +- 6.6 +- 2.1 MeV, which corresponds to the\nhyperfine splitting Delta M_hf(1S) = 68.5 +- 6.6 +- 2.0 MeV, and the branching\nfraction B(Upsilon(3S) -> gamma eta_b) = (7.1 +- 1.8 +- 1.1) x 10^-4. These\nresults agree with those previously reported by BaBar.", "category": "hep-ex" }, { "text": "Supersymmetry searches at the Tevatron: CDF and D0 collaborations analyzed up to 200 pb-1 of the delivered data in\nsearch for different supersymmetry signatures, so far with negative results. We\npresent results on searches for chargino and neutralino associated production,\nsquarks and gluinos, sbottom quarks, gauge mediated SUSY breaking and long\nlived heavy particles.", "category": "hep-ex" }, { "text": "Precise Neutron Lifetime Measurement Using Pulsed Neutron Beams at\n J-PARC: A neutron decays into a proton, an electron, and an anti-neutrino through the\nbeta-decay process. The decay lifetime ($\\sim$880 s) is an important parameter\nin the weak interaction. For example, the neutron lifetime is a parameter used\nto determine the |$V_{\\rm ud}$| parameter of the CKM quark mixing matrix. The\nlifetime is also one of the input parameters for the Big Bang Nucleosynthesis,\nwhich predicts light element synthesis in the early universe. However,\nexperimental measurements of the neutron lifetime today are significantly\ndifferent (8.4 s or 4.0$\\sigma$) depending on the methods. One is a bottle\nmethod measuring surviving neutron in the neutron storage bottle. The other is\na beam method measuring neutron beam flux and neutron decay rate in the\ndetector. There is a discussion that the discrepancy comes from unconsidered\nsystematic error or undetectable decay mode, such as dark decay. A new type of\nbeam experiment is performed at the BL05 MLF J-PARC. This experiment measured\nneutron flux and decay rate simultaneously with a time projection chamber using\na pulsed neutron beam. We will present the world situation of neutron lifetime\nand the latest results at J-PARC.", "category": "hep-ex" }, { "text": "Higgs and top physics reconstruction challenges and opportunities at\n FCC-ee: The Higgs bosons and the top quark decay into rich and diverse final states,\ncontaining both light and heavy quarks, gluons, photons as well as W and Z\nbosons. This article reviews the challenges involved in reconstructing Higgs\nand top events at the FCC-ee and identifies the areas where novel developments\nare needed. The precise identification and reconstruction of these final states\nat the FCC-ee rely on the capability of the detector to provide excellent\nflavour tagging, jet energy and angular resolution, and global kinematic event\nreconstruction. Excellent flavour tagging performance requires low-material\nvertex and tracking detectors, and advanced machine learning techniques as\nsuccessfully employed in LHC experiments. In addition, the Z pole run will\nprovide abundant samples of heavy flavour partons that can be used for\ncalibration of the tagging algorithms. For the reconstruction of jets, leptons,\nand missing energy, particle-flow algorithms are crucial to explore the full\npotential of the highly granular tracking and calorimeter systems, and give\naccess to excellent energy-momentum resolution and precise identification of\nheavy bosons in their hadronic decays. This enables, among many other key\nelements, the reconstruction of Higgsstrahlung processes with leptonically and\nhadronically decaying Z bosons, and an almost background-free identification of\ntop quark pair events. Exploiting the full available kinematic constraints\ntogether with exclusive jet clustering algorithms will allow for the\noptimisation of global event reconstruction with kinematic fitting techniques.", "category": "hep-ex" }, { "text": "Overview of the T2K long baseline neutrino oscillation experiment: Neutrino oscillations were discovered by atmospheric and solar neutrino\nexperiments, and have been confirmed by experiments using neutrinos from\naccelerators and nuclear reactors. It has been found that there are large\nmixing angles in the $\\nu_e \\to \\nu_\\mu$ and $\\nu_\\mu \\to \\nu_\\tau$\noscillations. The third mixing angle $\\theta_{13}$, which parameterizes the\nmixing between the first and the third generation, is constrainted to be small\nby the CHOOZ experiment result. The T2K experiment is a long baseline neutrino\noscillation experiment that uses intense neutrino beam produced at J-PARC and\nSuper-Kamiokande detector at 295 km as the far detector to measure\n$\\theta_{13}$ using $\\nu_e$ appearance. In this talk, we will give an overview\nof the experiment.", "category": "hep-ex" }, { "text": "Measurement of $b$-hadron pair production with the ATLAS detector in\n proton-proton collisions at $\\sqrt{s}=8$ TeV: A measurement of $b$-hadron pair production is presented, based on a data set\ncorresponding to an integrated luminosity of 11.4 fb$^{-1}$ of proton--proton\ncollisions recorded at $\\sqrt{s}=8$ TeV with the ATLAS detector at the LHC.\nEvents are selected in which a $b$-hadron is reconstructed in a decay channel\ncontaining $J/\\psi \\rightarrow \\mu\\mu$, and a second $b$-hadron is\nreconstructed in a decay channel containing a muon. Results are presented in a\nfiducial volume defined by kinematic requirements on three muons based on those\nused in the analysis. The fiducial cross section is measured to be $17.7 \\pm\n0.1 ($stat.$) \\pm 2.0 ($syst.$)$ nb. A number of normalised differential cross\nsections are also measured, and compared to predictions from the Pythia8,\nHerwig++, MadGraph5\\_aMC@NLO+Pythia8 and Sherpa event generators, providing new\nconstraints on heavy flavour production.", "category": "hep-ex" }, { "text": "W$^+$W$^-$ boson pair production in proton-proton collisions at\n $\\sqrt{s} =$ 13 TeV: A measurement of the W$^+$W$^-$ boson pair production cross section in\nproton-proton collisions at $\\sqrt{s} =$ 13 TeV is presented. The data used in\nthis study are collected with the CMS detector at the CERN LHC and correspond\nto an integrated luminosity of 35.9 fb$^{-1}$. The W$^+$W$^-$ candidate events\nare selected by requiring two oppositely charged leptons (electrons or muons).\nTwo methods for reducing background contributions are employed. In the first\none, a sequence of requirements on kinematic quantities is applied allowing a\nmeasurement of the total production cross section: 117.6 $\\pm$ 6.8 pb, which\nagrees well with the theoretical prediction. Fiducial cross sections are also\nreported for events with zero or one jet, and the change in the zero-jet\nfiducial cross section with the jet transverse momentum threshold is measured.\nNormalized differential cross sections are reported within the fiducial region.\nA second method for suppressing background contributions employs two random\nforest classifiers. The analysis based on this method includes a measurement of\nthe total production cross section and also a measurement of the normalized jet\nmultiplicity distribution in W$^+$W$^-$ events. Finally, a dilepton invariant\nmass distribution is used to probe for physics beyond the standard model in the\ncontext of an effective field theory, and constraints on the presence of\ndimension-6 operators are derived.", "category": "hep-ex" }, { "text": "Prospects for SUSY searches in CMS and ATLAS: We discuss how the CMS and ATLAS experiments are preparing for the analysis\nof first LHC data with emphasis on the search for supersymmetry. We will show\nthe importance of the understanding of detector, trigger, reconstruction and\nbackgrounds, and we will present realistic estimates of the reach of CMS and\nATLAS.", "category": "hep-ex" }, { "text": "Search for squarks and gluinos in final states with jets and missing\n transverse momentum at $\\sqrt{s}=$ 13 TeV with the ATLAS detector: A search for squarks and gluinos in final states containing hadronic jets,\nmissing transverse momentum but no electrons or muons is presented. The data\nwere recorded in 2015 by the ATLAS experiment in $\\sqrt{s}=$ 13 TeV\nproton--proton collisions at the Large Hadron Collider. No excess above the\nStandard Model background expectation was observed in 3.2 fb$^{-1}$ of analyzed\ndata. Results are interpreted within simplified models that assume R-parity is\nconserved and the neutralino is the lightest supersymmetric particle. An\nexclusion limit at the 95% confidence level on the mass of the gluino is set at\n1.51 TeV for a simplified model incorporating only a gluino octet and the\nlightest neutralino, assuming the lightest neutralino is massless. For a\nsimplified model involving the strong production of mass-degenerate first- and\nsecond-generation squarks, squark masses below 1.03 TeV are excluded for a\nmassless lightest neutralino. These limits substantially extend the region of\nsupersymmetric parameter space excluded by previous measurements with the ATLAS\ndetector.", "category": "hep-ex" }, { "text": "Measurement of the inelastic proton-proton cross section at sqrt(s) = 7\n TeV: A measurement is presented of the inelastic proton-proton cross section at a\ncentre-of-mass energy of sqrt(s) = 7 TeV. Using the CMS detector at the LHC,\nthe inelastic cross section is measured through two independent methods based\non information from (i) forward calorimetry (for pseudorapidity 3 < abs(eta) <\n5), in collisions where at least one proton loses more than 5E-6 of its\nlongitudinal momentum, and (ii) the central tracker (abs(eta) < 2.4), in\ncollisions containing an interaction vertex with more than 1, 2, or 3 tracks\nwith transverse momenta pT > 200 MeV. The measurements cover a large fraction\nof the inelastic cross section for particle production over about 9 units of\npseudorapidity and down to small transverse momenta. The results are compared\nwith those of other experiments, and with models used to describe high-energy\nhadronic interactions.", "category": "hep-ex" }, { "text": "First Direct Bound on the Total Width of the Top Quark in ppbar\n Collisions at sqrt(s) = 1.96 TeV: We present the first direct experimental bound on the total decay width of\nthe top quark using 955pb^-1 of the Tevatron's ppbar collisions recorded by the\nCollider Detector at Fermilab. We identify 253 top-antitop pair candidate\nevents. The distribution of reconstructed top quark mass from these events is\nfitted to templates representing different values of the top quark width. Using\na confidence interval based on likelihood ratio ordering, we extract an upper\nlimit at 95% C.L. of Gamma_t <13.1 GeV for an assumed top quark mass of 175\nGeV/c^2.", "category": "hep-ex" }, { "text": "Neutrino Factory and Muon Collider R&D: European, Japanese, and US Neutrino Factory designs are presented. The main\nR&D issues and associated R&D programs, future prospects, and the additional\nissues that must be addressed to produce a viable Muon Collider design, are\ndiscussed.", "category": "hep-ex" }, { "text": "Search for Theta(1540)^+ in exclusive proton-induced reaction p+C(N) \\to\n Theta^+ \\bar{K}^0 + C(N) at the energy of 70 GeV: A search for narrow Theta(1540)^+, a candidate for pentaquark baryon with\npositive strangeness, has been performed in an exclusive proton-induced\nreaction p+C(N) \\to Theta^+ \\bar{K}^0 + C(N) on carbon nuclei or quasifree\nnucleons at E_{beam}=70 GeV (sqrt{s} = 11.5 GeV) studying nK^+, pK_S and pK_L\ndecay channels of Theta(1540)^+ in four different final states of the Theta^+\n\\bar{K}^0 system. In order to assess the quality of the identification of the\nfinal states with neutron or K_L we reconstructed Lambda(1520)\\to nK_S and\nphi\\to K_LK_S decays in the calibration reactions p+C(N)\\to Lambda(1520)K^+ +\nC(N) and p+C(N)\\to p\\phi + C(N). We found no evidence for narrow pentaquark\npeak in any of the studied final states and decay channels. Assuming that the\nproduction characteristics of the Theta^+ \\bar{K^0} system are not drastically\ndifferent from those of the Lambda(1520)K^+ and p\\phi systems, we established\nupper limits on the cross section ratios\nsigma(Theta^+\\bar{K}^0)/sigma(Lambda(1520)K^+) < 0.02 and\nsigma(Theta^+\\bar{K}^0)/sigma(p\\phi) < 0.15 at 90% CL and a preliminary upper\nlimit for the forward hemisphere cross section sigma(Theta^+\\bar{K}^0) < 30\nnb/nucleon.", "category": "hep-ex" }, { "text": "Jet energy spectrum and substructure in $e^+e^-$ collisions at 91.2 GeV\n with ALEPH Archived Data: The first measurements of energy spectra and substructure of anti-$k_{T}$\njets in hadronic $Z^0$ decays in $e^+e^-$ collisions are presented. The\narchived $e^+e^-$ annihilation data at a center-of-mass energy of 91.2 GeV were\ncollected with the ALEPH detector at LEP in 1994. In addition to inclusive jet\nand leading dijet energy spectra, various jet substructure observables are\nanalyzed as a function of jet energy which includes groomed and ungroomed jet\nmass to jet energy ratios, groomed momentum sharing, and groomed jet radius.\nThe results are compared with perturbative QCD calculations and predictions\nfrom the SHERPA, HERWIG v7.1.5, PYTHIA 6, PYTHIA 8, and PYQUEN event\ngenerators. The jet energy spectra agree with perturbative QCD calculations\nwhich include the treatment of logarithms of the jet radius and threshold\nlogarithms. None of the event generators give a fully satisfactory description\nof the data.", "category": "hep-ex" }, { "text": "Perspectives for the detection and measurement of Supersymmetry in the\n focus point region of mSUGRA models with the ATLAS detector at LHC: This paper discusses the ATLAS potential to study Supersymmetry for the\n\"Focus-Point\" region of the parameter space of mSUGRA models. The potential to\ndiscovery a deviation from Standard Model expectations with the first few\n${fb}^{-1}$ of LHC data was studied using the parametrized simulation of the\nATLAS detector. Several signatures were considered, involving hard jets, large\nmissing energy, and either $b$-tagged jets, opposite-sign isolated electron or\nmuon pairs, or top quarks reconstructed exploiting their fully hadronic decays.\nWith only 1 ${fb}^{-1}$ of data each of these signatures may allow to observe\nan excess of events over Standard Model expectation with a statistical\nsignificance exceeding 5 standard deviations. An analytical expression was\nderived for the shape of the distribution of the dilepton invariant mass\narising from the three-body leptonic decay of the neutralinos under the\nhypothesis of heavy scalars, which is appropriate for the focus-point scenario.\nThe resulting function was used to fit the distribution of the dilepton\ninvariant mass obtained with simulated LHC data, and to extract the value of\ntwo kinematic endpoints measuring the $\\tilde \\chi^0_2 - \\tilde \\chi^0_1$ and\nthe $\\tilde \\chi^0_3 - \\tilde \\chi^0_1$ mass differences. This information was\nused to constrain the MSSM parameter space compatible with the data.", "category": "hep-ex" }, { "text": "Search for heavy Majorana neutrinos in e+/- e+/- plus jets and e+/-\n mu+/- plus jets events in proton-proton collisions at sqrt(s) = 8 TeV: A search is performed for heavy Majorana neutrinos (N) decaying into a W\nboson and a lepton using the CMS detector at the Large Hadron Collider. A\nsignature of two jets and either two same sign electrons or a same sign\nelectron-muon pair is searched for using 19.7 inverse femtobarns of data\ncollected during 2012 in proton-proton collisions at a centre-of-mass energy of\n8 TeV. The data are found to be consistent with the expected standard model\n(SM) background and, in the context of a Type-1 seesaw mechanism, upper limits\nare set on the cross section times branching fraction for production of heavy\nMajorana neutrinos in the mass range between 40 and 500 GeV. The results are\nadditionally interpreted as limits on the mixing between the heavy Majorana\nneutrinos and the SM neutrinos. In the mass range considered, the upper limits\nrange between 0.00015 - 0.72 for |V[eN]|^2 and 6.6E-5 - 0.47 for |V[eN]\nV*[muN]|^2 / ( |V[eN]|^2 + |V[muN]|^2 ), where V[lN] is the mixing element\ndescribing the mixing of the heavy neutrino with the SM neutrino of flavour l.\nThese limits are the most restrictive direct limits for heavy Majorana neutrino\nmasses above 200 GeV.", "category": "hep-ex" }, { "text": "Enhancing the hunt for new phenomena in dijet final-states using anomaly\n detection filters at the High-Luminosity Large Hadron Collider: In the realm of dijet searches in high-energy physics, a significant\nchallenge has emerged: with experiments producing more and more data, the\ntraditional methods of using analytic functions to describe dijet mass spectra\nstart to fail. To address this, we suggest the application of an anomaly\ndetection approach to eliminate less interesting background events based on\nevent final states. This method not only bypasses the limitations of\nconventional background models but also significantly enhances our ability to\ndetect potential signals of new physics. Through simulations that mimic the\nconditions of the upcoming High-Luminosity Large Hadron Collider, we\ndemonstrate the strength and efficiency of this approach in dealing with large\ndata volumes. The integration of unsupervised machine learning into our\nexperimental framework paves the way for a promising avenue to unveil hidden\nphysics discoveries within the overwhelming influx of data.", "category": "hep-ex" }, { "text": "Probing Gluons at the Spin Physics Detector: The Spin Physics Detector (SPD) at the Nuclotron based Ion Collider fAcility\n(NICA) is a multi-purpose experiment designed to study nucleon spin structure\nin the three dimensions. With capabilities to collide polarized protons and\ndeuterons with center of mass energy up to 27 GeV and luminosity up to $10^{32}\n\\rm cm^{-2} \\ s^{-1}$ for protons (an order of magnitude less for deuterons),\nthe experiment will allow measurements of cross-sections and spin asymmetries\nof hadronic processes sensitive to the unpolarized and various polarized\n(helicity, Sivers, Boer-Mulders) gluon distributions inside the nucleons.\nResults from the SPD will be complementary to the present high energy spin\nexperiments at the RHIC facility or future experiments like the EIC (at BNL)\nand AFTER (at LHC). SPD will provide data in moderate and large Bjorken-x for\nmuch improved global analyses of spin structures of the basic building blocks\nof Nature. With polarized deuteron collisions, SPD will be the unique\nlaboratory for probing tensor polarized gluon distributions. In addition, there\nare also possibilities of colliding other light nuclei like Carbon at reduced\ncollision energy and luminosity at the first stage of the experiment.", "category": "hep-ex" }, { "text": "Experimental and Phenomenological Investigations of the MiniBooNE\n Anomaly: This thesis covers a range of experimental and theoretical efforts to\nelucidate the origin of the $4.8\\sigma$ MiniBooNE low energy excess (LEE). We\nbegin with the follow-up MicroBooNE experiment, which took data along the BNB\nfrom 2016 to 2021. This thesis specifically presents MicroBooNE's search for\n$\\nu_e$ charged-current quasi-elastic (CCQE) interactions consistent with\ntwo-body scattering. The two-body CCQE analysis uses a novel reconstruction\nprocess, including a number of deep-learning-based algorithms, to isolate a\nsample of $\\nu_e$ CCQE interaction candidates with $75\\%$ purity. The analysis\nrules out an entirely $\\nu_e$-based explanation of the MiniBooNE excess at the\n$2.4\\sigma$ confidence level. We next perform a combined fit of MicroBooNE and\nMiniBooNE data to the popular $3+1$ model; even after the MicroBooNE results,\nallowed regions in $\\Delta m^2$-$\\sin^2 2_{\\theta_{\\mu e}}$ parameter space\nexist at the $3\\sigma$ confidence level. This thesis also demonstrates that the\nMicroBooNE data are consistent with a $\\overline{\\nu}_e$-based explanation of\nthe MiniBooNE LEE at the $<2\\sigma$ confidence level. Next, we investigate a\nphenomenological explanation of the MiniBooNE excess combining the $3+1$ model\nwith a dipole-coupled heavy neutral lepton (HNL). It is shown that a 500 MeV\nHNL can accommodate the energy and angular distributions of the LEE at the\n$2\\sigma$ confidence level while avoiding stringent constraints derived from\nMINER$\\nu$A elastic scattering data. Finally, we discuss the Coherent\nCAPTAIN-Mills experiment--a 10-ton light-based liquid argon detector at Los\nAlamos National Laboratory. The background rejection achieved from a novel\nCherenkov-based reconstruction algorithm will enable world-leading sensitivity\nto a number of beyond-the-Standard Model physics scenarios, including\ndipole-coupled HNLs.", "category": "hep-ex" }, { "text": "Recent neutrino oscillation result with the IceCube experiment: The IceCube South Pole Neutrino Observatory is a Cherenkov detector\ninstrumented in a cubic kilometer of ice at the South Pole. IceCube's primary\nscientific goal is the detection of TeV neutrino emissions from astrophysical\nsources. At the lower center of the IceCube array, there is a subdetector\ncalled DeepCore, which has a denser configuration that makes it possible to\nlower the energy threshold of IceCube and observe GeV-scale neutrinos, opening\nthe window to atmospheric neutrino oscillations studies. Advances in physics\nsensitivity have recently been achieved by employing Convolutional Neural\nNetworks to reconstruct neutrino interactions in the DeepCore detector. In this\ncontribution, the recent IceCube result from the atmospheric muon neutrino\ndisappearance analysis using the CNN-reconstructed neutrino sample is presented\nand compared to the existing worldwide measurements.", "category": "hep-ex" }, { "text": "Athermal Phonon Sensors in Searches for Light Dark Matter: In recent years, theoretical and experimental interest in dark matter (DM)\ncandidates have shifted focus from primarily Weakly-Interacting Massive\nParticles (WIMPs) to an entire suite of candidates with masses from the\nzeV-scale to the PeV-scale to 30 solar masses. One particular recent\ndevelopment has been searches for light dark matter (LDM), which is typically\ndefined as candidates with masses in the range of keV to GeV. In searches for\nLDM, eV-scale and below detector thresholds are needed to detect the small\namount of kinetic energy that is imparted to nuclei in a recoil. One such\ndetector technology that can be applied to LDM searches is that of\nTransition-Edge Sensors (TESs). Operated at cryogenic temperatures, these\nsensors can achieve the required thresholds, depending on the optimization of\nthe design.\n In this thesis, I will motivate the evidence for DM and the various DM\ncandidates beyond the WIMP. I will then detail the basics of TES\ncharacterization, expand and apply the concepts to an athermal phonon\nsensor--based Cryogenic PhotoDetector (CPD), and use this detector to carry out\na search for LDM at the surface. The resulting exclusion analysis provides the\nmost stringent limits in DM-nucleon scattering cross section (comparing to\ncontemporary searches) for a cryogenic detector for masses from 93 to 140 MeV,\nshowing the promise of athermal phonon sensors in future LDM searches.\nFurthermore, unknown excess background signals are observed in this LDM search,\nfor which I rule out various possible sources and motivate stress-related\nmicrofractures as an intriguing explanation. Finally, I will shortly discuss\nthe outlook of future searches for LDM for various detection channels beyond\nnuclear recoils.", "category": "hep-ex" }, { "text": "Measurements of two-particle correlations in $e^+e^-$ collisions at 91\n GeV with ALEPH archived data: Measurements of two-particle angular correlations of charged particles\nemitted in hadronic $Z$ decays are presented. The archived $e^+e^-$\nannihilation data at a center-of-mass energy of 91 GeV were collected with the\nALEPH detector at LEP between 1992 and 1995. The correlation functions are\nmeasured over a broad range of pseudorapidity and full azimuth as a function of\ncharged particle multiplicity. No significant long-range correlation is\nobserved in either the lab coordinate analysis or the thrust coordinate\nanalysis, where the latter is sensitive to a medium expanding transverse to the\ncolor string between the outgoing $q\\bar{q}$ pair from $Z$ boson decays. The\nassociated yield distributions in both analyses are in better agreement with\nthe prediction from the PYTHIA v6.1 event generator than from HERWIG v7.1.5.\nThey provide new insights to showering and hadronization modeling. These\nresults serve as an important reference to the observed long-range correlation\nin proton-proton, proton-nucleus, and nucleus-nucleus collisions.", "category": "hep-ex" }, { "text": "Search for \"Invisible\" Axion Dark Matter in the $3.3\\text{-}4.2~\u03bc$eV\n Mass Range: We report the results from a haloscope search for axion dark matter in the\n$3.3\\text{-}4.2~{\\mu}$eV mass range. This search excludes the axion-photon\ncoupling predicted by one of the benchmark models of \"invisible\" axion dark\nmatter, the KSVZ model. This sensitivity is achieved using a large-volume\ncavity, a superconducting magnet, an ultra low noise Josephson parametric\namplifier, and sub-Kelvin temperatures. The validity of our detection procedure\nis ensured by injecting and detecting blind synthetic axion signals.", "category": "hep-ex" }, { "text": "Rare $B$ decays at CMS: The Flavor Changing Neutral Current mediated decays $B \\rightarrow\n\\mu^{+}\\mu^{-}$ and $B^{0} \\rightarrow K^{*0}\\mu^{+}\\mu^{-}$ provide high\nsensitivity to new physics contributions. Sensitive observables include the\nbranching fraction, the muon forward-backward asymmetry, the fraction of\n$K^{*0}$ longitudinal polarisation and the differential branching fraction. We\nreport herein the recent results from CMS on these decay modes.", "category": "hep-ex" }, { "text": "Measurement of $A_\u0393$: The measurement of the charm CP violation observable $A_{\\Gamma}$ using 1\nfb$^{-1}$ of $pp$ collisions at $\\sqrt{s}=7$ TeV recorded by the LHCb detector\nin 2011 is presented. This new result is the most accurate to date.", "category": "hep-ex" }, { "text": "Kaon physics: Recent experimental progress: Numerous recent measurements of kaon decays are described, with an emphasis\non results offering constraints on chiral perturbation theory calculations. An\nup-to-date estimate of |Vus|f+(0) based on semileptonic kaon decay rates is\npresented.", "category": "hep-ex" }, { "text": "Measurement of direct photon pair production cross sections in ppbar\n collisions at sqrt(s)=1.96 TeV: We present a measurement of direct photon pair production cross sections\nusing 4.2 fb-1 of data collected with the D0 detector at the Fermilab Tevatron\nproton-antiproton Collider. We measure single differential cross sections as a\nfunction of the diphoton mass, the transverse momentum of the diphoton system,\nthe azimuthal angle between the photons, and the polar scattering angle of the\nphotons, as well as the double differential cross sections considering the last\nthree kinematic variables in three diphoton mass bins. The results are compared\nwith different perturbative QCD predictions and event generators.", "category": "hep-ex" }, { "text": "Results on ultra-peripheral interactions in Pb-Pb and p-Pb collisions in\n ALICE: Ultra-relativistic heavy ions generate strong electromagnetic fields which\noffer the possibility to study $\\gamma$-nucleus and $\\gamma$-proton\ninteractions at the LHC in the so called ultra-peripheral collisions (UPC).\n Here we report ALICE results on J/psi photoproduction measured in Pb-Pb\ncollisions at $\\sqrt{s_{\\rm NN}}$ = 2.76 TeV and in p-Pb collisions at\n$\\sqrt{s_{\\rm NN}}$ = 5.02 TeV.", "category": "hep-ex" }, { "text": "Cross-section measurements of top-quark pair production in association\n with a hard photon at 13 TeV with the ATLAS detector: 25 years after the top quark's discovery, the Large Hadron Collider at CERN\nproduces proton-proton collision data on unprecedented scales at unprecedented\nenergies - and has heralded an era of top-quark precision measurements. The\nproduction of a top-quark pair in association with a photon ($t\\bar{t}\\gamma$)\ngives access to the electromagnetic top-photon coupling, one of the fundamental\nproperties of the top quark. Various extensions of the Standard Model predict\nmodifications of the coupling strength or structure, and deviations from the\nStandard Model prediction of the $t\\bar{t}\\gamma$ production cross-section\nwould indicate new physics. With enough statistics available from the Large\nHadron Collider, the electron-muon channel has gained particular interest due\nto its high signal purity and precise available theory predictions.\n This thesis presents results with the full Run 2 dataset collected with the\nATLAS detector in proton-proton collisions at the Large Hadron Collider between\n2015 and 2018 at 13 TeV centre-of-mass energy, corresponding to an integrated\nluminosity of 139 fb$^{-1}$. In order to compare the results to fixed-order\ncalculations that include non-doubly-resonant diagrams, a combined measurement\nof $t\\bar{t}\\gamma + tW\\gamma$ is performed. The focus is placed on a\nmeasurement of the fiducial inclusive cross-section in the electron-muon\nchannel. Furthermore, the ATLAS data is unfolded to parton level and\nmeasurements of differential cross-sections as functions of several observables\nare presented. Both fiducial inclusive and differential results are compared to\nstate-of-the-art fixed-order calculations at next-to-leading order in QCD. An\nadditional focus of the thesis is placed on studies to use machine-learning\ntechniques, in particular deep neural networks, for the identification of\nprompt photons.", "category": "hep-ex" }, { "text": "First Observations of Separated Atmospheric Muon Neutrino and Muon\n Anti-Neutrino Events in the MINOS Detector: The complete 5.4 kton MINOS far detector has been taking data since the\nbeginning of August 2003 at a depth of 2070 meters water-equivalent in the\nSoudan mine, Minnesota. This paper presents the first MINOS observations of\nmuon neutrino and muon anti-neutrino charged-current atmospheric neutrino\ninteractions based on an exposure of 418 days. The ratio of upward to\ndownward-going events in the data is compared to the Monte Carlo expectation in\nthe absence of neutrino oscillations giving:\n R_data(up/down)/R_MC(up/down) = 0.62^{+0.19}_{-0.14} (stat.) +- 0.02 (sys.).\n An extended maximum likelihood analysis of the observed L/E distributions\nexcludes the null hypothesis of no neutrino oscillations at the 98 % confidence\nlevel. Using the curvature of the observed muons in the 1.3 T MINOS magnetic\nfield muon neutrino and muon anti-neutrino interactions are separated. The\nratio of muon neutrino to muon anti-neutrino events in the data is compared to\nthe Monte Carlo expectation assuming neutrinos and anti-neutrinos oscillate in\nsame manner giving:\n R_data(numubar/numu)/R_MC(numubar/numu) = 0.96^{+0.38}_{-0.27} (stat.) +-\n0.15 (sys.), where the errors are the statistical and systematic uncertainties.\nAlthough the statistics are limited, this is the first direct observation of\natmospheric neutrino interactions separately for muon neutrinos and muon\nanti-neutrinos.", "category": "hep-ex" }, { "text": "Combined measurements of anomalous charged trilinear gauge-boson\n couplings from diboson production in p-pbar collisions at sqrt(s)=1.96 TeV: We present measurements of the anomalous WWgamma and WWZ trilinear gauge\ncouplings from a combination of four diboson production and decay channels\nusing data collected by the D0 detector at the Fermilab Tevatron Collider.\nThese results represent the first high statistics combination of limits across\ndifferent diboson production processes at the Tevatron and use data\ncorresponding to an integrated luminosity of approximately 1 fb^-1. When\nrespecting SU(2)_L x U(1)_Y symmetry, we measure central values and 68% C.L.\nallowed intervals of kappa_gamma=1.07^+0.16_-0.20, lambda =0.00^+0.05_-0.04 and\ng_1^Z=1.05 +/- 0.06. We present the most stringent measurements to date for the\nW boson magnetic dipole and electromagnetic quadrupole moments of\nmu_W=2.02^+0.08_-0.09 (e/2M_W) and q_W=-1.00 +/- 0.09 (e/M^2_W), respectively.", "category": "hep-ex" }, { "text": "Linac*LHC Based ep, Gamma-p, eA, Gamma-A and FEL Gamma-A Colliders:\n Luminosity and Physics: Main parameters and physics goals of different colliders, which can be\nrealized if a special 1 TeV energy linear electron accelerator or corresponding\nlinear collider is constructed tangential to LHC, are discussed. It is shown\nthat L_(ep)=10^(32)cm^(-2)s^(-1) at sqrt(s_(ep))=5.29 TeV can be achieved\nwithin moderate upgrade of LHC parameters. Then, Gamma-p collider with he same\nluminosity and sqrt(s)=4.82 TeV can be realized using Compton backscattering of\nlaser beam off the electron beam. Concerning the nucleus beam,\nL*A=10^(31)cm^(-2)s^(-1) can be achieved at least for light and medium nuclei\nfor both eA and Gamma-A options. Finally, colliding of FEL beam from an\nelectron linac and nucleus beam from LHC will give a new opportunity to\ninvestigate nuclear spektroscopy and photo-nuclei reactions.", "category": "hep-ex" }, { "text": "Testing CPT and Lorentz Invariance with the Anomalous Spin Precession of\n the Muon: This article discusses tests of CPT and Lorentz invariance with data from the\nmuon g-2 experiment at Brookhaven National Laboratory. According to an\nextension of the Standard Model by Kostelecky et al., CPT/Lorentz violating\nterms in the Lagrangian induce a shift of the anomaly frequency omega_a of\nmuons in a magnetic field. This shift is predicted to be different for positive\nand negative muons and to oscillate with the Earth's sidereal frequency. We\ndiscuss the sensitivity of the g-2 experiment to different parameters of this\nStandard Model extension and propose an analysis method to search for sidereal\nvariations of omega_a.", "category": "hep-ex" }, { "text": "Exclusive $J/\u03c8$ and $\u03c8(2S)$ production in $pp$ collisions at\n $\\sqrt{s}=7$ TeV: Exclusive $J/\\psi$ and $\\psi(2S)$ vector meson production has been observed\nin the dimuon channel using the LHCb detector. The cross-section times\nbranching fractions to two muons with pseudorapidities between 2.0 and 4.5 are\nmeasured to be $ \\sigma_{pp\\rightarrow J/\\psi (\\rightarrow \\mu^{+} \\mu^{-})}\n(2.0 <\\eta_{\\mu^{\\pm}}< 4.5) = 307 \\pm 21 \\pm 36 \\text{pb},\n\\sigma_{pp\\rightarrow \\psi(2S) (\\rightarrow \\mu^{+} \\mu^{-})} (2.0\n<\\eta_{\\mu^{\\pm}}< 4.5) = 7.8 \\pm 1.3 \\pm 1.0 \\text{pb}, $ where the first\nuncertainties are statistical and the second are systematic. The measurements\nare found to be in good agreement with results from previous experiments and\ntheoretical predictions. The $J/\\psi$ photoproduction cross-section has been\nmeasured as a function of the photon-proton centre-of-mass energy. The results\nare consistent with measurements obtained at HERA and confirm a similar power\nlaw behaviour for the photoproduction cross-section.", "category": "hep-ex" }, { "text": "Recent results on $B \\to \u03bc^+ \u03bc^-$ decays with the CMS experiment: Results on $B \\to \\mu^+ \\mu^-$ decays with the CMS experiment are reported,\nusing 61 fb$^{-1}$ of data recorded during LHC Run 1 and 2016. With an improved\nmuon identification algorithm and refined unbinned maximum likelihood fitting\nmethods, the decay $B_s^0 \\to \\mu^+ \\mu^-$ is observed with a significance of\n5.6 standard deviations. Its branching fraction is measured to be BF($B^0_s \\to\n\\mu^+ \\mu^-$) = [2.9+/-0.7(exp)+/-0.2(frag)]$\\times 10^{-9}$, where the first\nerror is the combined statistical and systematic uncertainty and the second\nerror quantifies the uncertainty of the $B^0_s$ and $B^+$ fragmentation\nprobability ratio. The $B^0_s \\to \\mu^+ \\mu^-$ effective lifetime is\n$\\tau_{\\mu^+ \\mu^-} =1.70^{+0.61}_{-0.44}$ps. No evidence for the decay $B^0\n\\to \\mu^+ \\mu^-$ is found and an upper limit of BF($B^0 \\to \\mu^+ \\mu^-$) <\n3.6$\\times 10^{-10}$ (at 95% confidence level) is determined. All results are\nconsistent with the standard model of particle physics.", "category": "hep-ex" }, { "text": "Search for the Rare Leptonic Decay B- -> tau- nubar: We present a search for the decay $B^{-} \\to \\tau^{-} \\bar{\\nu}_{\\tau}$ in a\nsample of $88.9 \\times 10^{6}$ $B\\bar{B}$ pairs recorded with the BaBar\ndetector at the SLAC $B$-Factory. One of the two $B$ mesons from the\n$\\Upsilon(4S)$ is reconstructed in a hadronic or a semileptonic final state and\nthe decay products of the other $B$ in the event are analyzed for consistency\nwith a $B^{-} \\to \\tau^{-} \\bar{\\nu}_{\\tau}$ decay. We find no evidence of a\nsignal and set an upper limit on the branching fraction of $\\mathcal{B}(B^{-}\n\\to \\tau^{-} \\bar{\\nu}_{\\tau}) < 4.2 \\times 10^{-4}$ at the 90% confidence\nlevel.", "category": "hep-ex" }, { "text": "Measurement of jet fragmentation in Pb+Pb and $pp$ collisions at\n $\\sqrt{s_\\mathrm{NN}} = 2.76$ TeV with the ATLAS detector: The distributions of transverse momentum and longitudinal momentum fraction\nof charged particles in jets are measured in Pb+Pb and pp collisions with the\nATLAS detector at the LHC. The distributions are measured as a function of jet\ntransverse momentum and rapidity. The analysis utilises an integrated\nluminosity of 0.14 nb$^{-1}$ of Pb+Pb data and 4.0 pb$^{-1}$ of pp data\ncollected in 2011 and 2013, respectively, at the same centre-of-mass energy of\n2.76 TeV per colliding nucleon pair. The distributions measured in pp\ncollisions are used as a reference for those measured in Pb+Pb collisions in\norder to evaluate the impact on the internal structure of jets from the jet\nenergy loss of fast partons propagating through the hot, dense medium created\nin heavy-ion collisions. Modest but significant centrality-dependent\nmodifications of fragmentation functions in Pb+Pb collisions with respect to\nthose in pp collisions are seen. No significant dependence of modifications on\njet $p_{\\mathrm{T}}$ and rapidity selections is observed except for the\nfragments with the highest transverse momenta for which some reduction of\nyields is observed for more forward jets.", "category": "hep-ex" }, { "text": "Top Quark Current Experimental Status: Ten years after its discovery at the Tevatron collider, we still know little\nabout the top quark. Its large mass suggests it may play a key role in the\nmechanism of Electroweak Symmetry Breaking (EWSB), or open a window of\nsensitivity to new physics related to EWSB and preferentially coupled to it. To\ndetermine whether this is the case, precision measurements of top quark\nproperties are necessary. The high statistics samples being collected by the\nTevatron experiments during Run II start to incisively probe the top quark\nsector. This report summarizes the experimental status of the top quark,\nfocusing in particular on the recent measurements from the Tevatron.", "category": "hep-ex" }, { "text": "D meson nuclear modification factors in Pb-Pb collisions at {\\surd}sNN =\n 2.76 TeV, measured with the ALICE detector: The ALICE experiment has measured the D meson production in pp and Pb-Pb\ncollisions at the LHC at {\\surd}s = 7 and 2.76 TeV and {\\surd}sNN = 2.76 TeV\nrespectively, via the exclusive reconstruction of hadronic decay channels. The\nanalyses of the D0{\\to}K-pi+ and D+{\\to}K-pi+pi+ channels will be described and\nthe preliminary results for the D0 and D+ nuclear modification factor will be\npresented.", "category": "hep-ex" }, { "text": "High-purity germanium detector ionization pulse shapes of nuclear\n recoils, gamma interactions and microphonism: Nuclear recoil measurements with high-purity Germanium detectors are very\npromising to directly detect dark matter candidates. The main background\nsources in such experiments are natural radioactivity and microphonic noise.\nDigital pulse shape analysis is an encouraging approach to reduce the\nbackground originating from the latter. To study the pulse shapes of nuclear\nrecoil events we performed a neutron scattering experiment, which covered the\nionization energy range from 20 to 80 keV. We have measured ionization\nefficiencies as well and found an excellent agreement with the theory of\nLindhard. In a further experiment we measured pulse shapes of a radioactive\ngamma-source and found no difference to nuclear recoil pulse shapes. Pulse\nshapes originating from microphonics of a HPGe-detector are presented for the\nfirst time. A microphonic noise suppression method, crucial for dark matter\ndirect detection experiments, can therefore be calibrated with pulse shapes\nfrom gamma-sources.", "category": "hep-ex" }, { "text": "Measurement of the underground atmospheric muon charge ratio using the\n MINOS Near Detector: The magnetized MINOS Near Detector, at a depth of 225 meters of water\nequivalent (mwe), is used to measure the atmospheric muon charge ratio. The\nratio of observed positive to negative atmospheric muon rates, using 301 days\nof data, is measured to be 1.266+/-0.001(stat.)+0.015/-0.014(syst.). This\nmeasurement is consistent with previous results from other shallow underground\ndetectors, and is 0.108+/-0.019(stat. + syst.) lower than the measurement at\nthe functionally identical MINOS Far Detector at a depth of 2070 mwe. This\nincrease in charge ratio as a function of depth is consistent with an increase\nin the fraction of muons arising from kaon decay for increasing muon surface\nenergies.", "category": "hep-ex" }, { "text": "Point Cloud Generation using Transformer Encoders and Normalising Flows: Data generation based on Machine Learning has become a major research topic\nin particle physics. This is due to the current Monte Carlo simulation approach\nbeing computationally challenging for future colliders, which will have a\nsignificantly higher luminosity. The generation of collider data is similar to\npoint cloud generation, but arguably more difficult as there are complex\ncorrelations between the points which need to be modelled correctly. A\nrefinement model consisting of normalising flows and transformer encoders is\npresented. The normalising flow output is corrected by a transformer encoder,\nwhich is adversarially trained against another transformer encoder\ndiscriminator/critic. The model reaches state-of-the-art performance while\nyielding a stable training.", "category": "hep-ex" }, { "text": "Measurement of the branching fractions of the singly Cabibbo-suppressed\n decays $\u039b_{c}^{+}\\to p\u03b7$ and $\u039b_{c}^{+}\\to p\u03c9$: Based on 4.5 $\\mbox{fb$^{-1}$}$ $e^{+}e^{-}$ collision data collected with\nBESIII detector at seven energy points between 4.600 and 4.699 GeV, the\nbranching fractions for $\\Lambda_{c}^{+}\\to p\\eta$ and $\\Lambda_{c}^{+}\\to\np\\omega$ were measured by means of single-tag method. The branching fractions\nof $\\Lambda_{c}^{+}\\to p\\eta$ and $\\Lambda_{c}^{+}\\to p\\omega$ are determined\nto be $(1.57\\pm0.11_{\\rm {stat}}\\pm0.04_{\\rm{syst}})\\times10^{-3}$ and\n$(1.11\\pm0.20_{\\rm{stat}}\\pm0.07_{\\rm{syst}})\\times10^{-3}$, with a statistical\nsignificance of greater than 10 $\\sigma$ and 5.7 $\\sigma$, respectively. These\nresults are consistent with the previous measurements by BESIII, LHCb and\nBelle, and the result of $\\Lambda_{c}^{+}\\to p\\eta$ is the most precise to\ndate.", "category": "hep-ex" }, { "text": "Observation of Y(2175) in $J/\u03c8\\to \u03b7\u03c6f_0(980)$: The decays of $J/\\psi\\to \\eta\\phi f_0(980) (\\eta\\to \\gamma\\gamma, \\phi \\to\nK^+K^-, f_0(980)\\to\\pi^+\\pi^-)$ are analyzed using a sample of $5.8 \\times\n10^{7}$ $J/\\psi$ events collected with the BESII detector at the Beijing\nElectron-Positron Collider (BEPC). A structure at around $2.18 $GeV/$c^2$ with\nabout $5\\sigma$ significance is observed in the $\\phi f_0(980)$ invariant mass\nspectrum. A fit with a Breit-Wigner function gives the peak mass and width of\n$m=2.186\\pm 0.010 (stat)\\pm 0.006 (syst) $GeV/$c^2$ and $\\Gamma=0.065\\pm 0.023\n(stat)\\pm 0.017 (syst) $GeV/$c^2$, respectively, that are consistent with those\nof Y(2175), observed by the BABAR collaboration in the initial-state radiation\n(ISR) process $e^+e^-\\to\\gamma_{ISR}\\phi f_0(980)$. The production branching\nratio is determined to be $Br(J/\\psi\\to\\eta Y(2175))\\cdot Br(Y(2175)\\to\\phi\nf_0(980))\\cdot Br(f_0(980)\\to\\pi^+\\pi^-)=(3.23\\pm 0.75 (stat)\\pm0.73\n(syst))\\times 10^{-4}$, assuming that the Y(2175) is a $1^{--}$ state.", "category": "hep-ex" }, { "text": "KARMEN: Present Neutrino-Oscillation Limits and Perspectives after the\n Upgrade: The neutrino experiment KARMEN is situated at the beam stop neutrino source\nISIS. It provides nu_mu's, nu_e's and nu_mu_bar's in equal intensities from the\npi+ mu+ decay at rest. The oscillation channels nu_mu->nu_e and\nnu_mu_bar->nu_e_bar are investigated with a 56t liquid scintillation\ncalorimeter at a mean distance of 17.6m from the nu source. No evidence for\noscillations could be found with KARMEN, resulting in 90% CL exclusion limits\nof sin(2th) < 8.5 10^-3 (nu_mu_bar->nu_e_bar) and sin(2th) < 4.0 10^-2\n(nu_mu->nu_e) for Delta m^2 > 100eV^2. In 1996, the KARMEN neutrino experiment\nhas been upgraded by an additional veto system. Vetoing of cosmic muons passing\nthe 7000t massive iron shielding of the detector suppresses energetic neutrons\nfrom deep inelastic scattering of muons as well as from mu-capture in iron. Up\nto 1996, these neutrons penetrating into the detector represented the main\nbackground for the nu_mu_bar->nu_e_bar oscillation search. With an expected\nreduction of the background rate by a factor of 40 the experimental sensitivity\nfor nu_mu_bar->nu_e_bar will be significantly enhanced towards sin(2th) = 10^-3\nfor large Delta m^2.", "category": "hep-ex" }, { "text": "Improved Measurement of CP Violation in Neutral B Decays to c cbar s: We present updated measurements of time-dependent CP asymmetries in\nfully-reconstructed neutral B decays to several CP eigenstates containing a\ncharmonium meson. The measurements use a data sample of (383 +/- 4) x 10^6\nY(4S)-> BBbar decays collected with the BABAR detector at the PEP-II B factory.\nWe determine sin2beta = 0.714 +/- 0.032 (stat) +/- 0.018 (syst) and |lambda| =\n0.952 +/- 0.022 (stat) +/- 0.017 (syst).", "category": "hep-ex" }, { "text": "Search for $B^0 \\to p \\bar{p}$, $\u039b\\bar\u039b$ and $B^+ \\to p\n \\bar\u039b$ at Belle: We report results of a search for the charmless two-body baryonic decays B^0\n\\to p \\bar{p}, B^0 \\to \\Lambda \\bar{\\Lambda}, and B^+\\to p \\bar{\\Lambda} based\non the analysis of a 140 fb^{-1} data sample. We set 90% confidence level upper\nlimits on their branching fractions: B(B^0 \\to p \\bar{p}) < 4.1 x 10^{-7},\nB(B^0 \\to \\Lambda \\bar{\\Lambda}) < 6.9 x 10^{-7}$, and B(B^+ \\to p\n\\bar{\\Lambda}) < 4.9 x 10^{-7}.", "category": "hep-ex" }, { "text": "Search for pair production of second-generation leptoquarks at $\\sqrt{s}\n =$ 13 TeV: A search for pair production of second-generation leptoquarks is performed\nusing proton-proton collision data collected at $\\sqrt{s}=$ 13 TeV in 2016 with\nthe CMS detector at the CERN LHC, corresponding to an integrated luminosity of\n35.9 fb$^{-1}$. Final states with two muons and two jets, or with one muon, two\njets, and missing transverse momentum are considered. Second-generation scalar\nleptoquarks with masses less than 1530 (1285) GeV are excluded for $\\beta =$\n1.0 (0.5), where $\\beta$ is the branching fraction for the decay of a\nleptoquark to a charged lepton and a quark. The results of the search are also\ninterpreted as limits on the pair production of long-lived top squarks in an\n$R$-parity violating supersymmetry model that has a final state with two muons\nand two jets. These limits represent the most stringent limits to date on these\nmodels.", "category": "hep-ex" }, { "text": "Search for the Flavor Changing Neutral Current Decay t $\\to Zq$ in $p\n \\bar{p}$ Collisions at $\\sqrt{s}=1.96$: We report a search for the flavor changing neutral current (FCNC) decay of\nthe top quark \\tZq ($q=u,c$) in \\ppbar collisions at $\\sqrt{s} = 1.96\\tev$\nusing a data sample corresponding to an integrated luminosity of 1.9\\invfb\ncollected by the CDF II detector. This decay is strongly suppressed in the\nstandard model (SM) and an observation of a signal at the Tevatron would be an\nindication of physics beyond the SM. Using $Z+\\ge4$ jet final state candidate\nevents, both with and without an identified bottom quark jet, we discriminate\nsignal from background by exploiting kinematic constraints present in FCNC\nevents and obtain an upper limit of $\\btZq < 3.7%$ at 95% C.L.", "category": "hep-ex" }, { "text": "The NA62 experiment at CERN: status and perspectives: The future program of the NA62 experiment at CERN SPS is currently in\nadvanced stage of development. The main goal of the experiment is to measure\nthe branching ratio of the ultra-rare decay K^+ -> pi+\\nu\\nubar, by detecting\napproximately 80 events with a background on the order of 10%. In the present\npaper, the motivation behind this measurement and the overall design strategy\nof the experiment are briefly outlined. The experiment's construction status is\ndiscussed and perspectives are given for the first runs with the new detector.", "category": "hep-ex" }, { "text": "Review on low and high mass spectroscopy: We review the most recent experimental progress in the hadron spectroscopy,\nup to bottomonium mass. This covers the search for the J^PC=1^-+ exotic state,\nthe states in J/psi decays, the spin-singlets of heavy quarkonium, and the\ncharmoniumlike XYZ states.", "category": "hep-ex" }, { "text": "Search for charged Higgs bosons in decays of top quarks in p-pbar\n collisions at sqrt(s) = 1.96 TeV: We report the recent charged Higgs search in top quark decays in 2.2/fb CDF\ndata. This is the first attempt to search for charged Higgs using fully\nreconstructed mass assuming H->c-sbar in small tan beta region. No evidence of\na charged Higgs is observed in the CDF data, hence 95% upper limits are placed\nat B(t->H+b) < 0.1-0.3. The upper limits can be used to limit the generic\nnon-SM charged boson production in top quark decays.", "category": "hep-ex" }, { "text": "The ZEPLIN-III Anti-Coincidence Veto Detector: The design, optimisation and construction of an anti-coincidence veto\ndetector to complement the ZEPLIN-III direct dark matter search instrument is\ndescribed. One tonne of plastic scintillator is arranged into 52 bars\nindividually read out by photomultipliers and coupled to a gadolinium-loaded\npassive polypropylene shield. Particular attention has been paid to\nradiological content. The overall aim has been to achieve a veto detector of\nlow threshold and high efficiency without the creation of additional background\nin ZEPLIN-III, all at a reasonable cost. Extensive experimental measurements of\nthe components have been made, including radioactivity levels and performance\ncharacteristics. These have been used to inform a complete end-to-end Monte\nCarlo simulation that has then been used to calculate the expected performance\nof the new instrument, both operating alone and as an anti-coincidence detector\nfor ZEPLIN-III. The veto device will be capable of rejecting over 65% of\ncoincident nuclear recoil events from neutron background in the energy range of\ninterest in ZEPLIN-III. This will reduce the background in ZEPLIN-III from ~0.4\nto ~0.14 events per year in the WIMP acceptance region, a significant factor in\nthe event of a non-zero observation. Furthermore, in addition to providing\nvaluable diagnostic capabilities, the veto is capable of tagging over 15% for\ngamma-ray rejection, all whilst contributing no significant additional\nbackground. In conjunction with the replacement of the internal ZEPLIN-III\nphotomultiplier array, the new veto is expected to improve significantly the\nsensitivity of the ZEPLIN-III instrument to dark matter, allowing spin\nindependent WIMP-nucleon cross sections below 1E-8 pb to be probed.", "category": "hep-ex" }, { "text": "First Observation of the $\u03a3_{c}^{*+}$ Baryon and a New Measurement\n of the $\u03a3_{c}^{+}$ Mass: Using data recorded with the CLEO II and CLEO II.V detector configurations at\nthe Cornell Electron Storage Rings, we report the first observation and mass\nmeasurement of the $\\Sigma_c^{*+}$ charmed baryon, and an updated measurement\nof the mass of the $\\Sigma_c^+$ baryon. We find\n$M(\\Sigma_c^{*+})-M(\\Lambda_c^+)$= 231.0 +- 1.1 +- 2.0 MeV, and\n$M(\\Sigma_c^{+})-M(\\Lambda_c^+)$= 166.4 +- 0.2 +- 0.3 MeV, where the errors are\nstatistical and systematic respectively.", "category": "hep-ex" }, { "text": "Search for Deconfinement in NA49 at the CERN SPS: Experiment NA49 at the Cern SPS uses a large acceptance detector for a\nsystematic study of particle yields and correlations in nucleus-nucleus,\nnucleon-nucleus and nucleon-nucleon collisions. Preliminary results for Pb+Pb\ncollisions at 40, 80 and 158 A*GeV beam energy are shown and compared to\nmeasurements at lower and higher energies.", "category": "hep-ex" }, { "text": "Search for nearly mass-degenerate higgsinos using low-momentum\n mildly-displaced tracks in $pp$ collisions at $\\sqrt{s}$ = 13 TeV with the\n ATLAS detector: Higgsinos with masses near the electroweak scale can solve the hierarchy\nproblem and provide a dark matter candidate, while detecting them at the LHC\nremains challenging if their mass-splitting is $\\mathcal{O}$(1 GeV). This\nLetter presents a novel search for nearly mass-degenerate higgsinos in events\nwith an energetic jet, missing transverse momentum, and a low-momentum track\nwith a significant transverse impact parameter using 140 fb$^{-1}$ of\nproton-proton collision data at $\\sqrt{s}$ = 13 TeV collected by the ATLAS\nexperiment. For the first time since LEP, a range of mass-splittings between\nthe lightest charged and neutral higgsinos from 0.3 GeV to 0.9 GeV is excluded\nat 95% confidence level, with a maximum reach of approximately 170 GeV in the\nhiggsino mass.", "category": "hep-ex" }, { "text": "Quarkonia production in ultra-peripheral PbPb collisions at LHCb: Measurements of coherent charmonium production cross sections together with\ntheir ratio in ultra-peripheral PbPb collisions are studied at a\nnucleon-nucleon centre-of-mass energy of $5.02\\,\\mathrm{TeV}$, the differential\ncross-sections are measured as a function of rapidity and transverse momentum,\nseparately. The photo-production of \\jpsi mesons at low transverse momentum is\nstudied in peripheral PbPb collisions, which confirms coherent \\jpsi production\nin hadronic collisions. These latest results significantly improve previous\nmeasurements and are compared with some theoretical predictions.", "category": "hep-ex" }, { "text": "Storage Ring to Search for Electric Dipole Moments of Charged Particles\n -- Feasibility Study: The proposed method exploits charged particles confined as a storage ring\nbeam (proton, deuteron, possibly $^3$He) to search for an intrinsic electric\ndipole moment (EDM) aligned along the particle spin axis. Statistical\nsensitivities could approach 10$^{-29}$ e$\\cdot$cm. The challenge will be to\nreduce systematic errors to similar levels. The ring will be adjusted to\npreserve the spin polarisation, initially parallel to the particle velocity,\nfor times in excess of 15 minutes. Large radial electric fields, acting through\nthe EDM, will rotate the polarisation from the longitudinal to the vertical\ndirection. The slow rise in the vertical polarisation component, detected\nthrough scattering from a target, signals the EDM.\n The project strategy is outlined. A stepwise plan is foreseen, starting with\nongoing COSY activities that demonstrate technical feasibility. Achievements to\ndate include reduced polarization measurement errors, long horizontal plane\npolarization lifetimes, and control of the polarization direction through\nfeedback from scattering measurements. The project continues with a\nproof-of-capability measurement (precursor experiment; first direct deuteron\nEDM measurement), an intermediate prototype ring (proof-of-principle;\ndemonstrator for key technologies), and finally a high-precision electric-field\nstorage ring.", "category": "hep-ex" }, { "text": "Measurement of CP Asymmetry in B0 to Ks pi0 pi0 Decays: We present a measurement of the time-dependent CP asymmetry for the neutral\nB-meson decay into the CP = +1 final state Ks pi0 pi0, with Ks -> pi+ pi-. We\nuse a sample of approximately 227 million B-meson pairs recorded at the\nUpsilon(4S) resonance with the BABAR detector at the PEP-II B-Factory at SLAC.\n From an unbinned maximum likelihood fit we extract the mixing-induced\nCP-violation parameter S = 0.72 +/- 0.71 +/- 0.08 and the direct CP-violation\nparameter C = 0.23 +/- 0.52 +/- 0.13, where the first uncertainty is\nstatistical and the second systematic.", "category": "hep-ex" }, { "text": "Atmospheric Neutrino Physics with the MACRO detector: We present the measurement of the the flux and angular distribution of\natmospheric muon neutrinos using the MACRO detector. Three different event\ntopologies are detected in two different energy ranges. High energy neutrinos\n(E~80 GeV) via the identification of upward throughgoing muons. Lower energy\nneutrinos (E~ 4 GeV) via the upgoing stopping and partially contained downgoing\nmuons (ID+UGS), or via the partially contained upgoing muons (IU). The measured\nflux is reduced with respect to the predictions. For the high energy sample,\nglobally the flux reduction is $0.74\\pm 0.054_{stat+sys} \\pm 0.12_{th}$ and\nvaries with the zenith angle. The ratio of measured to expected events is\nalmost constant with the zenith angle for the low energy events, and is $0.57\n\\pm 0.08_{stat+sys} \\pm 0.14_{theor}$ for the IU sample, and $0.71 \\pm\n0.09_{stat+sys} \\pm 0.17_{theor}$ for the (ID+UGS). All the data sets are\nconsistent within a scenario of neutrino oscillations, with maximum mixing and\n$\\Delta m^2 \\sim 10^{-3}\\div 10^{-2} eV^2$.", "category": "hep-ex" }, { "text": "The Strangeness Physics Program at CLAS: An extensive program of strange particle production off the nucleon is\ncurrently underway with the CEBAF Large Acceptance Spectrometer (CLAS) in Hall\nB at Jefferson Laboratory. This talk will emphasize strangeness\nelectroproduction in the baryon resonance region between W=1.6 and 2.4 GeV,\nwhere indications of s-channel structure are suggestive of high-mass baryon\nresonances coupling to kaons and hyperons in the final state. Precision\nmeasurements of cross sections and polarization observables are being carried\nout with highly polarized electron and real photon beams at energies up to 6\nGeV. The near-term and longer-term future of this program will also be\ndiscussed.", "category": "hep-ex" }, { "text": "Search for supersymmetry with a compressed mass spectrum in the vector\n boson fusion topology with 1-lepton and 0-lepton final states in\n proton-proton collisions at $\\sqrt{s} =$ 13 TeV: A search for supersymmetric particles produced in the vector boson fusion\ntopology in proton-proton collisions is presented. The search targets final\nstates with one or zero leptons, large missing transverse momentum, and two\njets with a large separation in rapidity. The data sample corresponds to an\nintegrated luminosity of 35.9 fb$^{-1}$ of proton-proton collisions at\n$\\sqrt{s} =$ 13 TeV collected in 2016 with the CMS detector at the LHC. The\nobserved dijet invariant mass and lepton-neutrino transverse mass spectra are\nfound to be consistent with the standard model predictions. Upper limits are\nset on the cross sections for chargino ($\\widetilde\\chi_1^\\pm$) and neutralino\n($\\widetilde\\chi_2^0$) production with two associated jets. For a compressed\nmass spectrum scenario in which the $\\widetilde\\chi_1^\\pm$ and\n$\\widetilde\\chi_2^0$ decays proceed via a light slepton and the mass difference\nbetween the lightest neutralino $\\widetilde\\chi_1^0$ and the mass-degenerate\nparticles $\\widetilde\\chi_1^\\pm$ and $\\widetilde\\chi_2^0$ is 1 (30) GeV, the\nmost stringent lower limit to date of 112 (215) GeV is set on the mass of these\nlatter two particles.", "category": "hep-ex" }, { "text": "Study of the inclusive production of charged pions, kaons, and protons\n in pp collisions at sqrt(s) = 0.9, 2.76, and 7 TeV: Spectra of identified charged hadrons are measured in pp collisions at the\nLHC for sqrt(s) = 0.9, 2.76, and 7 TeV. Charged pions, kaons, and protons in\nthe transverse-momentum range pt approximately 0.1-1.7 GeV and for rapidities\nabs(y) < 1 are identified via their energy loss in the CMS silicon tracker. The\naverage pt increases rapidly with the mass of the hadron and the event\ncharged-particle multiplicity, independently of the center-of-mass energy. The\nfully corrected pt spectra and integrated yields are compared to various tunes\nof the PYTHIA6 and PYTHIA8 event generators.", "category": "hep-ex" }, { "text": "Evidence for D0-D0bar Mixing at Babar: We present evidence for D0-D0bar mixing in $D^0 \\to K^{+}\\pi^{-}$ decays from\n384 fb^{-1} of e+e- colliding-beam data recorded near sqrt(s)=10.6 GeV with the\nBabar detector at the PEP-II storage rings at SLAC. We find the mixing\nparameters ${x^{\\prime}}^2 = [-0.22 \\pm 0.30 (stat.) \\pm 0.21 (syst.)] \\times\n10^{-3}$ and $y^{\\prime} = [9.7 \\pm 4.4 (stat.) \\pm 3.1 (syst.)] \\times\n10^{-3}$, and a correlation between them of -0.94. This result is inconsistent\nwith the no-mixing hypothesis with a significance of 3.9 standard deviations.\nWe measure $R_{\\rm D}$, the ratio of doubly Cabibbo-suppressed to\nCabibbo-favored decay rates, to be $[0.303 \\pm 0.016 (stat.) \\pm 0.010 (syst.)]\n%$. We find no evidence for CP violation.", "category": "hep-ex" }, { "text": "Gamma Factory high-intensity muon and positron source: Exploratory\n studies: One of the fundamental challenges for future leptonic colliders and neutrino\nfactories as well as for high-sensitivity studies of lepton universality is to\ndesign and construct new high-intensity sources of muons and positrons. The\nnext-generation sources should increase the intensity of the presently\noperating ones by at least three orders of magnitude and include an important\noption of producing longitudinally polarized leptons. The main effort to\nachieve this goal has been focused, so far, on the proton-beam-driven muon\nsources and electron-beam-driven positron sources. In this paper, we present\nexploratory studies of an alternative scheme which is based on high-intensity\nmegawatt-class photon beams. Such beams could be delivered in the future by the\nGamma Factory (GF) project. One of the GF multiple goals is to increase the\nenergy range (by more than one order of magnitude) and the intensity (by more\nthan six orders of magnitude) of presently operating photon sources. Such a\nleap can be achieved by extending the present hadron-collider modus operandi of\nthe LHC with a new GF-operation-mode, allowing the collisions of beams with\nlaser pulses. The exploratory studies presented in this paper demonstrate that\nmore than 10$^{13}$ muons of both signs and more than 10$^{16}$\nelectrons/positrons per second can be produced by a GF source.", "category": "hep-ex" }, { "text": "W asymmetries at CDF and D0: We present recent W and charged lepton asymmetry measurements from the CDF\nand D0 experiments. Theoretical predictions agree with the CDF W asymmetry,\nmeasured using a new matrix element technique. These theoretical predictions\nare less consistent with the latest lepton asymmetry measurements from D0 and\nCDF, especially for high charged lepton transverse momentum.", "category": "hep-ex" }, { "text": "The KM3NeT Neutrino Telescope and the potential of a neutrino beam from\n Russia to the Mediterranean Sea: KM3NeT is a new generation neutrino telescope currently under construction at\ntwo sites in the Mediterranean Sea. At the Capo Passero site, 100 km off-shore\nSicily, Italy, a volume of more than one cubic kilometre of water will be\ninstrumented with optical sensors. This instrument, called ARCA, is optimized\nfor observing cosmic sources of TeV and PeV neutrinos. The other site, 40 km\noff-shore Toulon, France, will host a much denser array of optical sensors,\nORCA. With an energy threshold of a few GeV, ORCA will be capable to determine\nthe neutrino mass hierarchy through precision measurements of atmospheric\nneutrino oscillations. In this contribution, we review the scientific goals of\nKM3NeT and the status of its construction. We also discuss the scientific\npotential of a neutrino beam from Protvino, Russia to ORCA. We show that such\nan experiment would allow for a measurement of the CP-violating phase in the\nneutrino mixing matrix. To achieve a sensitivity competitive with that of the\nother planned long-baseline neutrino experiments such as DUNE and T2HK, an\nupgrade of the Protvino accelerator complex will be necessary.", "category": "hep-ex" }, { "text": "Experimental review of Lepton Flavor Violation searches: A review of the experimental status in searches for charged Lepton Flavor\nViolation (LFV) is presented. Searches for LFV in decays of leptons, heavy\nmesons, and bosons are explored, with an emphasis on the experiments providing\nthe best constraints in each sector. In addition, prospects for upper limits by\ncurrent and upcoming experiments in the next decade are discussed.", "category": "hep-ex" }, { "text": "Performance of the ALICE secondary vertex b-tagging algorithm in p-Pb\n collisions: The hot and dense nuclear matter, that is produced in heavy-ion collisions,\ncould be studied by jets originating from beauty quarks. In-medium energy loss\nof these quarks provides information on several properties of the quark-gluon\nplasma, produced in ultra-relativistic heavy-ion collisions. Reconstructed jets\nare powerful tools, since they offer access to kinematics of these\nhard-scattered partons. Beauty hadrons are specific for their long lifetime,\nlarge mass and large-multiplicity decays. Due to the long lifetime beauty\nhadrons decay at displaced secondary vertices. In the ALICE experiment,\nsecondary vertex properties are used to tag b-jets. The study of Monte Carlo\nbased performance of the b-tagging algorithm for charged jets in p-Pb\ncollisions at $\\sqrt{s_{\\mathrm{NN}}}=5.02$ TeV is discussed in proceedings.", "category": "hep-ex" }, { "text": "Measurements of $J/\u03c8$ and $\u03c8(2S)$ decays into $\u039b\n \\bar\u039b\u03c0^0$ and $\u039b\\bar\u039b\u03b7$: Using 58 million $J/\\psi$ and 14 million $\\psi(2S)$ events collected by the\nBESII detector at the BEPC, branching fractions or upper limits for the decays\n$J/\\psi$ and $\\psi(2S) \\to \\Lambda \\bar{\\Lambda}\\pi^0$ and $\\Lambda\n\\bar{\\Lambda}\\eta$ are measured. For the isospin violating decays, the upper\nlimits are determined to be ${\\cal B}(J/\\psi \\to \\Lambda\n\\bar{\\Lambda}\\pi^0)<6.4\\times 10^{-5}$ and ${\\cal B}(\\psi(2S) \\to \\Lambda\n\\bar{\\Lambda}\\pi^0)<4.9\\times 10^{-5}$ at the 90% confidence level. The isospin\nconserving process $J/\\psi \\to \\Lambda \\bar{\\Lambda}\\eta$ is observed for the\nfirst time, and its branching fraction is measured to be ${\\cal B}(J/\\psi \\to\n\\Lambda \\bar{\\Lambda}\\eta)=(2.62\\pm 0.60\\pm 0.44)\\times 10^{-4}$, where the\nfirst error is statistical and the second one is systematic. No $\\Lambda\n\\bar{\\Lambda}\\eta$ signal is observed in $\\psi(2S)$ decays, and ${\\cal\nB}(\\psi(2S) \\to \\Lambda \\bar{\\Lambda}\\eta)<1.2\\times 10^{-4}$ is set at the 90%\nconfidence level. Branching fractions of $J/\\psi$ decays into $\\Sigma^+ \\pi^-\nbar{\\Lambda}$ and $\\bar{\\Sigma}^- \\pi^+ \\Lambda$ are also reported, and the sum\nof these branching fractions is determined to be ${\\cal B}(J/\\psi \\to\n\\Sigma^+\\pi^- \\bar{\\Lambda} + c.c.)=(1.52\\pm 0.08\\pm 0.16)\\times 10^{-3}$.", "category": "hep-ex" }, { "text": "Top and Higgs Physics at the Tevatron: We present a summary of our experimental understanding of the top quark and\ndiscuss the significant improvements expected in Run II at the Fermilab\nTevatron Collider. We also discuss prospects for a Higgs boson discovery at the\nTevatron.", "category": "hep-ex" }, { "text": "$CP$-violating triple-product asymmetries in Charm decays: The use of triple-product correlations is described in relation to the search\nfor $CP$ violation in 4-body charm meson decays. The latest results from the\nLHCb and BaBar Collaborations are reported. A novel interpretation of the\nasymmetries from triple-product correlations is used for the BaBar results,\nwhich enables the extraction of information on the properties of $D$ decays\nunder parity and charge-conjugation transformations.", "category": "hep-ex" }, { "text": "The Inclusive Jet Cross Section in ppbar Collisions at sqrt{s}=1.8 TeV\n using the kT Algorithm: The central inclusive jet cross section has been measured using a\nsuccessive-combination algorithm for reconstruction of jets. The measurement\nuses 87.3 pb^{-1} of data collected with the D0 detector at the Fermilab\nTevatron ppbar Collider during 1994-1995. The cross section, reported as a\nfunction of transverse momentum (pT>60 GeV) in the central region of\npseudorapidity (|\\eta|<0.5), exhibits reasonable agreement with next-to-leading\norder QCD predictions, except at low pT where the agreement is marginal.", "category": "hep-ex" }, { "text": "Search for $B^{+}\\to K^{+}\u03bd\\bar\u03bd$ decays using an inclusive\n tagging method at Belle II: A search for the flavor-changing neutral-current decay $B^{+}\\to\nK^{+}\\nu\\bar{\\nu}$ is performed at the Belle II experiment at the SuperKEKB\nasymmetric energy electron-positron collider. The results are based on a data\nsample corresponding to an integrated luminosity of $63\\,\\mbox{fb}^{-1}$\ncollected at the $\\Upsilon{(4S)}$ resonance and a sample of $9\\,\\mbox{fb}^{-1}$\ncollected at an energy $60\\mathrm{\\,Me\\kern -0.1em V}$ below the resonance. A\nnovel measurement method is employed, which exploits topological properties of\nthe $B^{+}\\to K^{+}\\nu\\bar{\\nu}$ decay that differ from both generic\nbottom-meson decays and light-quark pair production. This inclusive tagging\napproach offers a higher signal efficiency compared to previous searches. No\nsignificant signal is observed. An upper limit on the branching fraction of\n$B^{+}\\to K^{+}\\nu\\bar{\\nu}$ of $4.1 \\times 10^{-5}$ is set at the 90%\nconfidence level.", "category": "hep-ex" }, { "text": "Axion Haloscope Using an 18 T High Temperature Superconducting Magnet: We report details on the axion dark matter search experiment that uses the\ninnovative technologies of a High-Temperature Superconducting (HTS) magnet and\na Josephson Parametric Converter (JPC). An 18 T HTS solenoid magnet is\ndeveloped for this experiment. The JPC is used as the first stage amplifier to\nachieve a near quantum-limited low-noise condition. The first dark matter axion\nsearch was performed with the 18 T axion haloscope. The scan frequency range is\nfrom 4.7789 GHz to 4.8094 GHz (30.5 MHz range). No significant signal\nconsistent with Galactic dark matter axion is observed. Our results set the\nbest limit of the axion-photon-photon coupling ($g_{a\\gamma\\gamma}$) in the\naxion mass range of 19.764 to 19.890 $\\mu$eV. Using the Bayesian method, the\nupper bounds of $g_{a\\gamma\\gamma}$ are set at\n0.98$\\times|g_{a\\gamma\\gamma}^{\\text{KSVZ}}|$\n(1.11$\\times|g_{a\\gamma\\gamma}^{\\text{KSVZ}}|$) in the mass ranges of 19.764 to\n19.771 $\\mu$eV (19.863 to 19.890 $\\mu$eV), and at 1.76\n$\\times|g_{a\\gamma\\gamma}^{\\text{KSVZ}}|$ in the mass ranges of 19.772 to\n19.863 $\\mu$eV with 90\\% confidence level, respectively. We report design,\nconstruction, operation, and data analysis of the 18 T axion haloscope\nexperiment.", "category": "hep-ex" }, { "text": "Search for Supersymmetry with Photon at CMS: We present the searches for supersymmetry (SUSY) in two channels, two photons\nplus missing transverse energy and a photon plus a lepton plus missing\ntransverse energy with the CMS detector using approximately 36 $\\rm{pb}^{-1}$\nof pp collision at 7 TeV. No excess of events above the standard model\npredictions is found. Limits are set for the squark, gluino and wino masses in\nthe general gauge-mediated SUSY context.", "category": "hep-ex" }, { "text": "Search for a light charged Higgs boson decaying into $c\\bar{s}$ at CMS: We present results on the search for a light charged Higgs boson that can be\nproduced in the decay of a top quark and later decays into a charm and an\nantistrange quark. The analysis is performed using $19.7\\invfb$ pp collison\ndata recorded with the CMS detector at LHC.", "category": "hep-ex" }, { "text": "Photon Events with Missing Energy at sqrt(s) = 183 to 189 GeV: The production of single photons has been studied in the reaction e+e- ->\ngamma + invisible particles at centre-of-mass energies of 183 GeV and 189 GeV.\nA previously published analysis of events with multi-photon final states\naccompanied by missing energy has been updated with 189 GeV data. The data were\ncollected with the DELPHI detector and correspond to integrated luminosities of\nabout 51 pb^{-1} and 158 pb^{-1} at the two energies. The number of light\nneutrino families is measured to be 2.84 +/- 0.15(stat) +/- 0.14(syst). The\nabsence of an excess of events beyond that expected from Standard Model\nprocesses is used to set limits on new physics as described by supersymmetric\nand composite models. A limit on the gravitational scale is also determined.", "category": "hep-ex" }, { "text": "First Results from ABRACADABRA-10 cm: A Search for Sub-$\u03bc$eV Axion\n Dark Matter: The axion is a promising dark matter candidate, which was originally proposed\nto solve the strong-CP problem in particle physics. To date, the available\nparameter space for axion and axion-like particle dark matter is relatively\nunexplored, particularly at masses $m_a\\lesssim1\\,\\mu$eV. ABRACADABRA is a new\nexperimental program to search for axion dark matter over a broad range of\nmasses, $10^{-12}\\lesssim m_a\\lesssim10^{-6}$ eV. ABRACADABRA-10 cm is a\nsmall-scale prototype for a future detector that could be sensitive to the QCD\naxion. In this Letter, we present the first results from a 1 month search for\naxions with ABRACADABRA-10 cm. We find no evidence for axion-like cosmic dark\nmatter and set 95% C.L. upper limits on the axion-photon coupling between\n$g_{a\\gamma\\gamma}<1.4\\times10^{-10}$ GeV$^{-1}$ and\n$g_{a\\gamma\\gamma}<3.3\\times10^{-9}$ GeV$^{-1}$ over the mass range\n$3.1\\times10^{-10}$ eV - $8.3\\times10^{-9}$ eV. These results are competitive\nwith the most stringent astrophysical constraints in this mass range.", "category": "hep-ex" }, { "text": "Hashing and metric learning for charged particle tracking: We propose a novel approach to charged particle tracking at high intensity\nparticle colliders based on Approximate Nearest Neighbors search. With hundreds\nof thousands of measurements per collision to be reconstructed e.g. at the High\nLuminosity Large Hadron Collider, the currently employed combinatorial track\nfinding approaches become inadequate. Here, we use hashing techniques to\nseparate measurements into buckets of 20-50 hits and increase their purity\nusing metric learning. Two different approaches are studied to further resolve\ntracks inside buckets: Local Fisher Discriminant Analysis and Neural Networks\nfor triplet similarity learning. We demonstrate the proposed approach on\nsimulated collisions and show significant speed improvement with bucket\ntracking efficiency of 96% and a fake rate of 8% on unseen particle events.", "category": "hep-ex" }, { "text": "Determination of Solar Neutrino Oscillation Parameters using 1496 Days\n of Super-Kamiokande-I Data: A number of different fits to solar neutrino mixing and mass square\ndifference were performed using 1496 days of Super-Kamiokande-I's solar\nneutrino data. These data select two allowed areas at large neutrino mixing\nwhen combined with either the solar $^8$B flux prediction of the standard solar\nmodel or the SNO interaction rate measurements. A global fit combining SK data\nwith the solar neutrino interaction rates measured by Homestake, SNO,\nGallex/GNO and SAGE prefers a single allowed area, the Large Mixing Angle\nsolution, at the 98.9% confidence level. The mass square difference $\\Delta\nm^2$ between the two mass eigenstates ranges from about 3 to\n$19\\times10^{-5}$eV$^2$, while the mixing angle $\\theta$ is in the range of\n$\\tan^2\\theta\\approx$0.25--0.65.", "category": "hep-ex" }, { "text": "Leptonic Charm Decays: We review the recent experimental results on D and Ds meson leptonic decays\nfrom CLEO-c, Belle, and BABAR, which results in the decay constants f_D= (206.7\n+- 8.9) MeV and f_Ds= (257.3 +- 5.3) MeV. The latter is an average obtained by\nthe Heavy Flavor Averaging Group (HFAG). Comparisons with Lattice QCD (LQCD)\ncalculations are discussed.", "category": "hep-ex" }, { "text": "Measurement of $\u03c3(\u039b_b)/\u03c3(B^0) \\times\n BR(\u039b_b\\to\u039b_c\u03c0^-) / BR(B^0\\to D^+\u03c0^-)$ in $p\\bar{p}$\n Collisions at $\\sqrt{s}=1.96$ TeV: We present the first observation of the baryon decay\n$\\Lambda_b\\to\\Lambda_c\\pi^-$ followed by $\\Lambda_c\\to p K^-\\pi^+$ in 106 pb-1\nof $p\\bar{p}$ collisions at $\\sqrt{s} = 1.96$ TeV in the CDF experiment. In\norder to reduce systematic error, the measured rate for $\\Lambda_b$ decay is\nnormalized to the kinematically similar meson decay $B^0\\to D^+\\pi^-$ followed\nby $D^+\\to\\pi^+K^-\\pi^+$. We report the ratio of production cross sections\n($\\sigma$) times the ratio of branching fractions (BR) for the momentum region\nintegrated above $p_T > 6$ GeV/c and pseudorapidity range $|\\eta| < 1.3$:\n$\\sigma(p\\bar{p}\\to \\Lambda_b X) / \\sigma (p\\bar{p}\\to B^0 X) \\times\nBR(\\Lambda_b\\to\\Lambda_c\\pi^-) / BR(B^0\\to D^+\\pi^-) = 0.82 \\pm 0.08(stat) \\pm\n0.11(syst) \\pm 0.22 (BR(\\Lambda_c\\to p K^-\\pi^+))$.", "category": "hep-ex" }, { "text": "Measurements of Absolute Hadronic Branching Fractions of D Mesons: Using e+e- collisions recorded at the psi(3770) resonance with the CLEO-c\ndetector at the Cornell Electron Storage Ring, we determine absolute hadronic\nbranching fractions of charged and neutral D mesons. Among measurements for\nboth Cabibbo-favored and Cabibbo-suppressed modes, we obtain reference\nbranching fractions B(D0 -> K-pi+)=(3.91 +- 0.08 +- 0.09)% and B(D+ ->\nK-pi+pi+)=(9.5 +- 0.2 +- 0.3)%, where the uncertainties are statistical and\nsystematic, respectively. Using a determination of the integrated luminosity,\nwe also extract the e+e- -> DDbar cross sections.", "category": "hep-ex" }, { "text": "Study of B --> pi l nu and B --> rho l nu decays and determination of\n |Vub|: We present an analysis of exclusive charmless semileptonic B-meson decays\nbased on 83 million BBbar pairs recorded with the BABAR detector at the\nUpsilon(4S) resonance. Using isospin symmetry, we measure branching fractions\nB(B0 --> pi- l+ nu) = (1.38 +- 0.10 +- 0.16 +- 0.08) x 10^-4 and B(B0 --> rho-\nl+ nu) = (2.14 +- 0.21 +- 0.48 +- 0.28) x 10^-4, where the errors are\nstatistical, experimental systematic, and due to form-factor shape\nuncertainties. We compare the measured distribution in q^2, the\nmomentum-transfer squared, with theoretical predictions for the form factors\nfrom lattice QCD and light-cone sum rules, and extract the\nCabibbo-Kobayashi-Maskawa (CKM) matrix element |V_{ub}| = (3.82 +- 0.14 +- 0.22\n+- 0.11 +0.88 -0.52) x 10^-3 from B --> pi l nu, where the fourth error\nreflects the uncertainty of the form-factor normalization.", "category": "hep-ex" }, { "text": "Physics of CP Violation and Rare Decays: Lectures note for Cargese 99 Summer School Particle Physics: Ideas and Recent\nDevelopment NATO Advanced Institute, Corsica, July 26-August 7, 1999", "category": "hep-ex" }, { "text": "Measurement of the Top Quark Mass in the Dilepton Channel: We report a measurement of the top quark mass using six candidate events for\nthe process pbarp->ttbar->l^+ nu l^- nubar b bbar + X, observed in the D0\nexperiment at the Fermilab ppbar collider. Using maximum likelihood fits to the\ndynamics of the decays, we measure a mass for the top quark of m(top) = 168.4\n+- 12.3 (stat) +- 3.6 (syst) GeV/c^2. We combine this result with our previous\nmeasurement in the ttbar->l+jets channel to obtain m(top) = 172.1 +- 7.1\nGeV/c^2 as the best value of the mass of the top quark measured by D0.", "category": "hep-ex" }, { "text": "Recent results on charmonium-like (exotic) XYZ states at the\n BESIII/BEPCII experiment in Beijing/China: With about 12 fb$^{-1}$ collected XYZ data sets, BESIII continues the\nexploration of the exotic charmonium-like states. In this talk, recent results\non the measurements of the spin-parity determination of $Z_{\\rm c}(3900)$, as\nwell as on line-shapes of $e^+e^- \\rightarrow J/\\psi\\,\\pi\\pi, h_{\\rm c}\\pi\\pi,\n\\psi(2S)\\,\\pi^0\\pi^0/\\pi^+\\pi^-$, and $\\pi^+ D^0 D^{*-}$ from open charm are\ndiscussed. Also, the recent observation of $e^+ e^- \\rightarrow \\phi\n\\chi_{c1/2}$ at $\\sqrt(s)=4.6$ GeV is reported.", "category": "hep-ex" }, { "text": "NA48: Rare Decay Results: Recent results on the kaon rare decays measured in NA48 experiment at CERN\nare presented.", "category": "hep-ex" }, { "text": "Lorentz Angle Measurement for CO2/Isobutane Gas Mixtures: We have developed a Lorentz angle measurement system for cool gas mixtures in\nthe course of our R&D for a proposed JLC central drift chamber (JLC-CDC). The\nmeasurement system is characterized by the use of two laser beams to produce\nprimary electrons and flash ADCs to read their signals simultaneously. With\nthis new system, we have measured Lorentz angles for CO2/isobutane gas mixtures\nwith different proportions (95:5, 90:10, and 85:15), varying drift field from\n0.6 to 2.0 kV/cm and magnetic field up to 1.5 T. The results of the measurement\nare in good agreement with GARFIELD/MAGBOLTZ simulations.", "category": "hep-ex" }, { "text": "Branching Fraction Measurements of Charged B Decays to K*+K+K-,\n K*+pi+K-, K*+K+pi- and K*+pi+pi- Final States: Branching fraction and asymmetry measurements of charmless $B^+\\to\nK^{*+}h^+_1h^-_2$ (where $h_{1,2}$ = $K$, $\\pi$) decays are presented, using a\ndata sample of 232 million $\\Upsilon(4S) \\to$ $BB$ decays collected with the\nBaBar detector at the SLAC PEP-II asymmetric-energy $B$ factory. Using a\nmaximum likelihood fit, the following branching fraction results were obtained:\n${\\cal B}$($B^+ \\to K^{*+}K^+ K^-)$ = (36.2 $\\pm$ 3.3 $\\pm$ 3.6) $\\times$\n10$^{-6}$ and ${\\cal B}$($B^+$ $\\to$ $K^{*+}\\pi^+\\pi^-$) = (75.3 $\\pm$ 6.0\n$\\pm$ 8.1) $\\times$ 10$^{-6}$. Upper limits were set for ${\\cal B}$($B^+$ $\\to$\n$K^{*+}\\pi^+ K^-$) $<$ 11.8 $\\times$ 10$^{-6}$ and ${\\cal B}$($B^+$ $\\to$\n$K^{*+}K^+ \\pi^-$) $<$ 6.1 $\\times$ 10$^{-6}$ at 90% confidence level. The\ncharge asymmetries for the decays $B^+ \\to K^{*+}K^+ K^-$ and $B^+$ $\\to$\n$K^{*+}\\pi^+\\pi^-$ were measured to be ${\\cal A}_{K^*KK} = 0.11 \\pm 0.08 \\pm\n0.03$ and ${\\cal A}_{K^*\\pi\\pi} = 0.07 \\pm 0.07 \\pm 0.04$, respectively. The\nfirst error quoted on branching fraction and asymmetry measurements is\nstatistical and the second systematic.", "category": "hep-ex" }, { "text": "Search for Lepton Flavor Violating tau Decays at B-factories: Lepton flavor violations in charged lepton give good signatures for the new\nphysics. We review recent searches for lepton flavor violation in tau decays at\nB-factories. In these searches, optimization for background reduction is\nimportant to obtain high sensitivity. No evidence for these decays is observed\nand 90% confidence level upper limits have been set on the branching fractions\nat the O(10^{-8}) level.", "category": "hep-ex" }, { "text": "Measuring the CP properties of the Higgs sector at electron-positron\n colliders: The violation of CP symmetry at the electro-weak scale is one of the\nessential ingredients for electro-weak baryogenesis. It is therefore of great\ninterest to map the CP properties of the Higgs sector in as much detail as\npossible. A linear electron-positron Higgs factory collider will provide many\nopportunities to probe the CP nature of the Higgs sector, thanks to access to\nseveral Higgs production processes at a wide range of centre-of-mass energies.\nIn this paper we report on two studies based on full simulation of detector\nresponse and realistic reconstruction algorithms: 1) a study of $h \\to \\tau\n\\tau$ at ILC-250, in which mixing of CP eigenstates can be measured to a\nprecision of 75~mrad; and 2) the current status of an ongoing study of the\n$ZZ$--fusion process at 1.4 TeV CLIC and 1 TeV ILC, for which we expect to\nachieve concrete results during the Snowmass study period.", "category": "hep-ex" }, { "text": "Work on the interplay among $h^+$, $h^{-}$ and hadron pair transverse\n spin asymmetries in SIDIS: In the fragmentation of a transversely polarized quark a left-right\nasymmetry, the Collins asymmetry, is expected for each hadron produced in the\nprocess $\\mu N \\rightarrow \\mu ' h^{+} h^{-} X$. Similarly, an asymmetry is\nalso expected for the hadron pair, the dihadron asymmetry. Both asymmetries\nhave been measured to be different from zero on transversely polarised proton\ntargets and have allowed for first extractions of the transversity\ndistributions. From the high statistics COMPASS data we have further\ninvestigated these asymmetries getting strong indications that the two\nmechanisms are driven by a common physical process.", "category": "hep-ex" }, { "text": "Observation of the radiative decays of $\u03a5(1S)$ to $\u03c7_{c1}$: We report the first observation of the radiative decay of the $\\Upsilon(1S)$\ninto a charmonium state. The statistical significance of the observed signal of\n$\\Upsilon(1S) \\to \\gamma \\chi_{c1}$ is 6.3 standard deviations including\nsystematics. The branching fraction is calculated to be Br($\\Upsilon(1S) \\to\n\\gamma \\chi_{c1}$) = (4.7^{+2.4}_{-1.8} (stat) ^{+0.4}_{-0.5} (sys)) * 10^{-5}.\nWe also searched for $\\Upsilon(1S)$ radiative decays into $\\chi_{c0,2}$ and\n$\\eta_c(1S,2S)$ and set upper limits on their branching fractions. These\nresults are obtained from a 24.9 fb^{-1} data sample collected with the Belle\ndetector at the KEKB asymmetric-energy $e^+e^-$ collider at a center-of-mass\nenergy equal to the $\\Upsilon(2S)$ mass using $\\Upsilon(1S)$ tagging by the\n$\\Upsilon(2S) \\to \\Upsilon(1S) \\pi^+\\pi^-$ transitions.", "category": "hep-ex" }, { "text": "Search for $D^0\\to\u03b3\u03b3$ and improved measurement of the\n branching fraction for $D^0 \\to \u03c0^0\u03c0^0$: Using $2.92$ fb$^{-1}$ of electron-positron annihilation data collected at\n$\\sqrt{s} = 3.773$~GeV with the BESIII detector, we report the results of a\nsearch for the flavor-changing neutral current process $D^0\\to\\gamma\\gamma$\nusing a double-tag technique. We find no signal and set an upper limit at\n$90\\%$ confidence level for the branching fraction of $B(D^0\\to\\gamma\\gamma) <\n3.8\\times10^{-6}$. We also investigate $D^0$-meson decay into two neutral\npions, obtaining a branching fraction of $B(D^0\\to\\pi^0\\pi^0) =\n(8.24\\pm0.21(\\text{stat.})\\pm0.30(\\text{syst.}))\\times10^{-4}$, the most\nprecise measurement to date and consistent with the current world average", "category": "hep-ex" }, { "text": "Search for a standard model-like Higgs boson in the mass range between\n 70 and 110 GeV in the diphoton final state in proton-proton collisions at\n $\\sqrt{s} =$ 8 and 13 TeV: The results of a search for a standard model-like Higgs boson in the mass\nrange between 70 and 110 GeV decaying into two photons are presented. The\nanalysis uses the data set collected with the CMS experiment in proton-proton\ncollisions during the 2012 and 2016 LHC running periods. The data sample\ncorresponds to an integrated luminosity of 19.7 (35.9) fb$^{-1}$ at $\\sqrt{s}\n=$8 (13) TeV. The expected and observed 95% confidence level upper limits on\nthe product of the cross section and branching fraction into two photons are\npresented. The observed upper limit for the 2012 (2016) data set ranges from\n129 (161) fb to 31 (26) fb. The statistical combination of the results from the\nanalyses of the two data sets in the common mass range between 80 and 110 GeV\nyields an upper limit on the product of the cross section and branching\nfraction, normalized to that for a standard model-like Higgs boson, ranging\nfrom 0.7 to 0.2, with two notable exceptions: one in the region around the Z\nboson peak, where the limit rises to 1.1, which may be due to the presence of\nDrell-Yan dielectron production where electrons could be misidentified as\nisolated photons, and a second due to an observed excess with respect to the\nstandard model prediction, which is maximal for a mass hypothesis of 95.3 GeV\nwith a local (global) significance of 2.8 (1.3) standard deviations.", "category": "hep-ex" }, { "text": "A study of the nuclear medium influence on neutral strange particle\n production in deep inelastic neutrino scattering: The influence of nuclear effects on the production of neutral strange\nparticles ($V^{\\circ}$) is investigated using the data obtained with SKAT\npropane-freon bubble chamber irradiated in the neutrino beam (with $E_{\\nu}$ =\n3-30 GeV) at Serpukhov accelerator. The measured mean multiplicity of\n$V^{\\circ}$ particles in nuclear interactions, ${}_A$ =\n0.096$\\pm$0.011, is found to exceed significantly that in 'quasinucleon'\ninteractions, ${}_N$ = 0.059$\\pm$0.012. The ratio of\n${\\rho}_{V^{\\circ}}$ =${}_A/{}_N$ =1.61$\\pm$0.23\nis larger than that for $\\pi^{-}$ mesons, ${\\rho}_{\\pi^-}$ = 1.10$\\pm$0.03. It\nis shown that a dominant part of the multiplicity gain of $V^{\\circ}$ particles\ncan be explained by intranuclear interactions of produced pions.", "category": "hep-ex" }, { "text": "Measurement of Open Beauty Production at HERA: The first observation of open b production in ep collisions is reported. An\nevent sample containing muons and jets has been selected which is enriched in\nsemileptonic b quark decays. The visible cross section \\sigma(ep -> b \\bar{b}X\n-> \\mu X') for Q^2 < 1 GeV^2, 0.1 < y < 0.8 is measured to be\n0.176+-0.016(stat.)+0.026-0.017(syst.) nb for the muons to be detected in the\nrange 35 deg < \\theta^\\mu < 130 deg and \\pt^\\mu > 2.0 GeV in the laboratory\nframe. The expected visible cross section based on a NLO QCD calculation is\n0.104+-0.017 nb. The cross sections for electroproduction with Q^2<1 GeV^2 and\nphotoproduction are derived from the data and found to be \\sigma(ep-> e\nb\\bar{b}X) = 7.1+-0.6(stat.)+1.5-1.3(syst.) nb and \\sigma(\\gamma p-> b\\bar{b}\nX) = 111+-10(stat.)+23-20(syst.) at an average \\sim 180 GeV,\nrespectively.", "category": "hep-ex" }, { "text": "Measurement of the intrinsic electron neutrino component in the T2K\n neutrino beam with the ND280 detector: The T2K experiment has reported the first observation of the appearance of\nelectron neutrinos in a muon neutrino beam. The main and irreducible background\nto the appearance signal comes from the presence in the neutrino beam of a\nsmall intrinsic component of electron neutrinos originating from muon and kaon\ndecays. In T2K, this component is expected to represent 1.2% of the total\nneutrino flux. A measurement of this component using the near detector (ND280),\nlocated 280 m from the target, is presented. The charged current interactions\nof electron neutrinos are selected by combining the particle identification\ncapabilities of both the time projection chambers and electromagnetic\ncalorimeters of ND280. The measured ratio between the observed electron\nneutrino beam component and the prediction is 1.01+-0.10 providing a direct\nconfirmation of the neutrino fluxes and neutrino cross section modeling used\nfor T2K neutrino oscillation analyses. Electron neutrinos coming from muons and\nkaons decay are also separately measured, resulting in a ratio with respect to\nthe prediction of 0.68+-0.30 and 1.10+-0.14, respectively.", "category": "hep-ex" }, { "text": "Search for Higgs boson decays into two new low-mass spin-0 particles in\n the 4$b$ channel with the ATLAS detector using $pp$ collisions at $\\sqrt{s}=\n 13$ TeV: This paper describes a search for beyond the Standard Model decays of the\nHiggs boson into a pair of new spin-0 particles subsequently decaying into\n$b$-quark pairs, $H \\rightarrow aa \\rightarrow (b\\bar{b})(b\\bar{b})$, using\nproton-proton collision data collected by the ATLAS detector at the Large\nHadron Collider at center-of-mass energy $\\sqrt{s}=13$ TeV. This search focuses\non the regime where the decay products are collimated and in the range $15 \\leq\nm_a \\leq 30$ GeV and is complementary to a previous search in the same final\nstate targeting the regime where the decay products are well separated and in\nthe range $20 \\leq m_a \\leq 60$ GeV. A novel strategy for the identification of\nthe $a \\rightarrow b\\bar{b}$ decays is deployed to enhance the efficiency for\ntopologies with small separation angles. The search is performed with 36\nfb$^{-1}$ of integrated luminosity collected in 2015 and 2016 and sets upper\nlimits on the production cross-section of $H \\rightarrow aa \\rightarrow\n(b\\bar{b})(b\\bar{b})$, where the Higgs boson is produced in association with a\n$Z$ boson.", "category": "hep-ex" }, { "text": "Search for microscopic black holes in pp collisions at sqrt(s) = 8 TeV: A search for microscopic black holes and string balls is presented, based on\na data sample of pp collisions at sqrt(s) = 8 TeV recorded by the CMS\nexperiment at the Large Hadron Collider and corresponding to an integrated\nluminosity of 12 inverse femtobarns. No excess of events with energetic\nmultiparticle final states, typical of black hole production or of similar new\nphysics processes, is observed. Given the agreement of the observations with\nthe expected standard model background, which is dominated by QCD multijet\nproduction, 95% confidence limits are set on the production of semiclassical or\nquantum black holes, or of string balls, corresponding to the exclusions of\nmasses below 4.3 to 6.2 TeV, depending on model assumptions. In addition,\nmodel-independent limits are set on new physics processes resulting in\nenergetic multiparticle final states.", "category": "hep-ex" }, { "text": "Search for admixture of scalar top quarks in the ttbar lepton+jets final\n state at sqrt(s)=1.96 TeV: A search for pair production of the lightest supersymmetric partner of the\ntop quark is performed in the lepton+jets channel using 0.9 fb-1 of data\ncollected by the D0 experiment. Kinematic differences between scalar top quark\npair production and the dominant top quark pair production background are used\nto separate the two processes. First limits from Run II of the Fermilab\nTevatron Collider for the scalar top quark decaying to a chargino and a b quark\nare obtained for scalar top quark masses of 130-190 GeV and chargino masses of\n90-150 GeV.", "category": "hep-ex" }, { "text": "Electrons and Heavy Quark at PHENIX Detector: Measurement of heavy quark production is one of the tools used to investigate\nthe matter produced in extremely hot and dense conditions in heavy ion\ncollisions at RHIC. The PHENIX experiment has measured mid-rapidity transverse\nmomentum spectra of electrons. After subtracting the photonic background\ncontribution, the electron spectra are mainly due to semileptonic decays of\nhadrons containing heavy quarks and therefore provide a measurement of heavy\nquark production and its energy loss in hot and dense matter. This paper will\npresent the technique used by the PHENIX experiment and recent results on heavy\nquark production in p+p, d+Au and Au+Au collisions at sqrt{s_NN}=200 GeV.", "category": "hep-ex" }, { "text": "A Review of Charmed Baryon Experimental Data: A review of the experimental results on charmed baryons, with an accent on\nthose reported most recently. Talk given at FPCP conference, U. Penn, May 2002.", "category": "hep-ex" }, { "text": "Search for Magnetic Monopoles Trapped in Matter: There have been many searches for magnetic monopoles in flight, but few for\nmonopoles in matter. We have searched for magnetic monopoles in meteorites,\nschists, ferromanganese nodules, iron ores and other materials. The detector\nwas a superconducting induction coil connected to a SQUID (Superconducting\nQuantum Interference Device) with a room temperature bore 15 cm in diameter. We\ntested a total of more than 331 kg of material including 112 kg of meteorites.\nWe found no monopole and conclude the overall monopole/nucleon ratio in the\nsamples is $<1.2 \\times 10^{-29}$ with a 90\\% confidence level.", "category": "hep-ex" }, { "text": "Strategies for precision measurements of the charge asymmetry of the W\n boson mass at the LHC within the ATLAS experiment: This thesis dissertation presents a prospect for a measurement of the charge\nasymmetry of the W boson mass (MW+ - MW-) at the LHC within the ATLAS\nexperiment. This measurement is of primordial importance for the LHC\nexperimental program, both as a direct test of the charge sign independent\ncoupling of the W bosons to the fermions and as a mandatory preliminary step\ntowards the precision measurement of the charge averaged W boson mass. This\nlast pragmatic point can be understood since the LHC specific collisions will\nprovide unprecedented kinematics for the positive and negative channels while\nthe SPS and Tevatron collider produced W+ and W- on the same footing. For that\nreason, the study of the asymmetries between W+ and W- in Drell--Yan like\nprocesses (production of single W decaying into leptons), studied to extract\nthe properties of the W boson, is described thoroughly in this document. Then,\nthe prospect for a measurement of MW+ - MW- at the LHC is addressed in a\nperspective intending to decrease as much as possible the systematic errors\nthat will inevitably comes from the misunderstanding of both phenomenological\nand apparatus modeling. For that matter strategies have been devised\nspecifically for the present measurement to display robustness with respect to\nthe main uncertainties. These strategies consist of introducing new observables\nalong with considering specific LHC running modes and configurations of the\nATLAS tracker. Eventually we show that the present (2009) precision can be\nimproved at the LHC by a factor of 20 and argue that such a precision is beyond\nthe reach of the standard measurement and calibration methods imported to the\nLHC from the Tevatron program.", "category": "hep-ex" }, { "text": "The European Spallation Source neutrino Super Beam: After measuring in 2012 a relatively large value of the neutrino mixing angle\n$\\theta_{13}$, the door is now open to observe for the first time a possible CP\nviolation in the leptonic sector. The measured value of $\\theta_{13}$ also\nprivileges the 2nd oscillation maximum for the discovery of CP violation\ninstead of the usually used 1st maximum. The sensitivity at this 2nd\noscillation maximum is about three times higher, with a lower influence of\nsystematic errors, than for the 1st maximum. Going to the 2nd oscillation\nmaximum necessitates a very intense neutrino beam with the appropriate energy.\nThe world's most intense pulsed spallation neutron source, the European\nSpallation Source, will have a proton linac with 5 MW power and 2 GeV energy.\nThis linac, under construction, also has the potential to become the proton\ndriver of the world's most intense neutrino beam with high probability to\ndiscover a neutrino CP violation. The physics performance of that neutrino\nSuper Beam in conjunction with a megaton underground Water Cherenkov neutrino\ndetector installed at a distance of about 500~km from ESS has been evaluated.\nIn addition, the choice of such detector will extent the physics program to\nproton-decay and astrophysics searches. The ESS proton linac upgrades, the\naccumulator ring needed for proton pulse compression, the target station, the\nfar detector and the physics potential are described. In addition to neutrinos,\nthis facility will also produce at the same time a copious number of muons\nwhich could be used by a low energy neutrino facility for sterile neutrino\nsearches, a future Neutrino Factory or a Muon Collider. The ESS neutron\nfacility will be fully ready by 2023 at which moment the upgrades for the\nneutrino facility could start.", "category": "hep-ex" }, { "text": "A Measurement of the Ratio of the W + 1 Jet to Z + 1 Jet Cross Sections\n with ATLAS: The measurement of hadronic activity recoiling against W and Z vector bosons\nprovides an important test of perturbative QCD, as well as a method of\nsearching for new physics in a model independent fashion. We present a study of\nthe cross-section ratio for the production of W and Z gauge bosons in\nassociation with exactly one jet Rjet = {\\sigma}(W + 1jet)/{\\sigma}(Z + 1jet),\nin pp collisions at \\surds = 7 TeV. The study is performed in the electron and\nmuon channels with data collected with the ATLAS detector at the LHC. The ratio\nRjet is studied as a function of the cumulative transverse momentum\ndistribution of the jet. This result can be compared to NLO pQCD calculations\nand the prediction from LO matrix element + parton shower generators.", "category": "hep-ex" }, { "text": "On the Relation between the True Directions of Neutrinos and the\n Reconstructed Directions of Neutrinos in L/E Analysis Performed by\n Super-Kamiokande Collaboration Part2: In the previous paper (Part1), we have verified that the SK assumption on the\ndirection does not hold in the analysis of neutrino events occurred inside the\nSK detector, which is the cornerstone for their analysis of zenith angle\ndistributions of neutrino events. Based on the correlation between L_nu and\nL_mu (Figures~16 to 18 in Part1) and the correlation between E_nu and E_mu\n(Figure19 in Part1), we have made four possible L/E analyses, namely L_nu/E_nu,\nL_nu/E_mu, L_mu/E_mu and L_mu/E_nu. Among four kinds of L/E analyses, we have\nshown that only L_nu/E_nu analysis can give the signature of maximum\noscillations clearly, not only the first maximum oscillation but also the\nsecond and third maximum oscillation and etc., as they should be, while the\nL_mu/E_mu analysis which are really done by Super-Kamiokande Collaboration\ncannot give any maximum oscillation at all. It is thus concluded from those\nresults that the experiments with the use of the cosmic-ray beam for neutrino\noscillation, such as Super-Kamiokande type experiment, are unable to lead the\nmaximum oscillation from their L/E analysis, because the incident neutrino\ncannot be observed due to its neutrality. Therefore, we would suggest\nSuper-Kamiokande Collaboration to re-analyze the zenith angle distribution of\nthe neutrino events which occur inside the detector carefully, since L_nu and\nL_mu are alternative expressions of the cosine of the zenith angle for the\nincident neutrino and that for the emitted muon, respectively.", "category": "hep-ex" }, { "text": "Search for higher mass resonances via KK decay channel in pp collisions\n with ALICE at the LHC: The quark model has proven successful in describing the basic building blocks\nof strongly interacting particles in the Standard Model, where hadronic states\nconsist of quarks and gluons. At the same time, Lattice QCD predicts the\npossibility of glueball candidates in the mass range \\mbox{1550--1750}\nMeV/$c^2$, which have never been observed. The experimental search for the\nexistence of mesons with no quark content is both interesting and challenging\nas the glueball is very likely to mix with surrounding quark-antiquark scalar\nmeson states with the same quantum numbers. The large statistics data sample\ncollected by ALICE in pp collisions at the highest LHC center-of-mass energy\nprovides an opportunity to measure high mass resonances, whose characteristics\nand internal structure are still unknown. In this article, we report on the\nmeasurements of invariant mass distributions of higher mass resonances using\nthe decay channels of K$^{0}_\\mathrm{S}\\mathrm{K}^{0}_\\mathrm{S}$ and\nK$^{+}$K$^{-}$ pairs in pp collisions at $\\sqrt{s}$ = 13 TeV using ALICE\ndetector at midrapidity.", "category": "hep-ex" }, { "text": "Measurement of Time-Dependent CP Asymmetries and the CP-odd Fraction in\n the Decay B^0 --> D^{*+}D^{*-}: We present a measurement of time-dependent CP asymmetries and an updated\ndetermination of the CP-odd fraction in the decay B^0 --> D^{*+}D^{*-}. The\nmeasurements are derived from a data sample of 88 times 10^{6} B bar{B} pairs\ncollected by the BaBar detector at the PEP-II energy asymmetric B Factory at\nSLAC. All results are preliminary.", "category": "hep-ex" }, { "text": "Measurements of $\\mathrm{J/\u03c8\\rightarrow e^{+}e^{-}}$ with ALICE at\n the LHC: The ALICE detector provides excellent capabilities to study quarkonium\nproduction at the Large Hadron Collider (LHC). Heavy quarkonia, bound states of\ncharm or beauty quark anti-quark pairs such as the $\\mathrm{J/\\psi}$, are\nexpected to be produced by initial hard processes. Thus they will provide\ninsight into the earliest and hottest stages of AA collisions where the\nformation of a Quark-Gluon Plasma (QGP) is expected. Furthermore,\nhigh-precision data from pp collisions represent an essential baseline for the\nmeasurement of nuclear modifications in heavy-ions and serve also as a crucial\ntest for several models of quarkonium hadroproduction. In addition, the study\nof pA collisions allows to investigate nuclear modifications due to Cold\nNuclear Matter (CNM) effects. In ALICE, $\\mathrm{J/\\psi}$ were measured in pp\nand Pb--Pb collisions down to $p_{\\mathrm T}$ = 0 via their di-electron decay\nchannel in the central barrel ($|y| <$ 0.8). Results on the nuclear\nmodification factor ($R_{\\mathrm{AA}}$) at central rapidities in Pb--Pb\ncollisions at $\\sqrt{s_{\\mathrm{NN}}} = 2.76$ TeV will be shown and their\nimplications discussed. A separation of the prompt and non-prompt components is\nalso possible down to $p_{\\mathrm T}$ of the $\\mathrm{J/\\psi}$ of 2 GeV/$c$.", "category": "hep-ex" }, { "text": "New Physics Effects in $B$ Decays: The two $B$-factories, Belle and BaBar, has been played major roles in the B\ndecays study. Their wonderful design and excellent operation enables their\nfruitful analysis results. Also recently the Tevatron experiments, CDF and DO,\njoin the game with their $B_S$ studies. From the experimental results of $B$\ndecay studies, we learn that most of measurements are consistent with the\nStandard Model (SM). Some discrepancies from the SM has been found in the\nmeasurements of the phases and magnitudes of CKM unitary triangle. There are\nalso various theoretical models that possibly give the contributions. These\nwill relay on further validation with new experimental results.", "category": "hep-ex" }, { "text": "Evidence for a neutral near-threshold structure in the $K^{0}_{\\rm S}$\n recoil-mass spectra in $e^+e^-\\rightarrow K^{0}_{\\rm S}D_s^+D^{*-}$ and\n $e^+e^-\\rightarrow K^{0}_{\\rm S}D_s^{*+}D^{-}$: We study the processes $e^+e^-\\rightarrow K^{0}_{\\rm S}D_s^+D^{*-}$ and\n$e^+e^-\\rightarrow K^{0}_{\\rm S}D_s^{*+}D^{-}$, as well as their charge\nconjugated processes, at five center-of-mass energies between 4.628~GeV and\n4.699~GeV, using data samples corresponding to an integrated luminosity of\n$3.8~\\rm{fb^{-1}}$ collected by the BESIII detector at the BEPCII storage ring.\nBased on a partial reconstruction technique, we find evidence of a structure\nnear the thresholds for $D_s^+D^{*-}$ and $D_s^{*+}D^{-}$ production in the\n$K^{0}_{\\rm S}$ recoil-mass spectrum, which we refer to as the $\nZ_{cs}(3985)^0$. Fitting with a Breit-Wigner line shape, we find the mass of\nthe structure to be $(3992.2\\pm{1.7}\\pm{1.6})~\\rm{MeV}/c^2$ and the width to be\n$(7.7_{-3.8}^{+4.1}\\pm{4.3})~\\rm{MeV}$, where the first uncertainties are\nstatistical and the second are systematic. The significance of the $\nZ_{cs}(3985)^0$ signal is found to be $4.6\\sigma$ including both the\nstatistical and systematic uncertainty. We report the Born cross section\nmultiplied by the branching fraction at different energy points. The mass of\nthe $Z_{cs}(3985)^0$ is close to that of the $Z_{cs}(3985)^+$. Assuming SU(3)\nsymmetry, the cross section of the neutral channel is consistent with that of\nthe charged one. Hence, we conclude that the $Z_{cs}(3985)^0$ is the isospin\npartner of the $Z_{cs}(3985)^+$.", "category": "hep-ex" }, { "text": "HFLAV $\u03c4$ branching fractions fit and measurements of Vus with $\u03c4$\n lepton data: We report the status of the Heavy Flavour Averaging Group (HFLAV) averages of\nthe $\\tau$ lepton measurements We then update the latest published HFLAV global\nfit of the $\\tau$ lepton branching fractions (Spring 2017) with recent results\nby BABAR. We use the fit results to update the Cabibbo-Kobayashi-Maskawa (CKM)\nmatrix element Vus measurements with the $\\tau$ branching fractions. We combine\nthe direct $\\tau$ branching fraction measurements with indirect predictions\nusing kaon branching fractions measurements to improve the determination of Vus\nusing $\\tau$ branching fractions. The Vus determinations based on the inclusive\nbranching fraction of $\\tau$ to strange final states are about $3\\sigma$ lower\nthan the Vus determination from the CKM matrix unitarity.", "category": "hep-ex" }, { "text": "Recent charm results at Belle: We present the selected recent charm results at Belle: (1) the $CP$\nasymmetries and branching fractions for the decays of charm mesons, i.e.\n$D^{0}\\to\\pi^{+}\\pi^{-}\\eta,\\,K^{+}K^{-}\\eta$ and $D^{0}\\to\\phi\\eta$;\n$D_{s}^{+}\\to K^{+}\\pi^{0},\\,K^{+}\\eta$ and\n$D_{s}^{+}\\to\\pi^{+}\\pi^{0},\\,\\pi^{+}\\eta$. (2) the branching fractions for the\ndecays of charmed baryons, i.e. $\\Lambda_{c}^{+}\\to p\\pi^{0},\\,p\\eta$;\n$\\Lambda_{c}^{+}\\to\\Lambda\\pi^{+}\\eta,\\,\\Sigma^0\\pi^{+}\\eta$ and intermediate\nprocesses $\\Lambda_{c}^{+}\\to\\Lambda(1670)\\pi^{+},\\,\\eta\\Sigma(1385)^+$;\n$\\Xi_c^0\\to\\Lambda\\bar{K}^{*0},\\,\\Sigma^0\\bar{K}^{*0}$ and $\\Sigma^+K^{*-}$.\n(3) properties of excited charmed baryons, i.e. search for electromagnetic\ntransition $\\Xi_c(2790,2815)^{+,0}\\to\\Xi_c^{+,0}\\gamma$; and determination of\nspin-parity of $\\Xi_c(2970)^+$.", "category": "hep-ex" }, { "text": "Search for the Decay tau to seven pion (pizero): A search for the decay of the tau lepton to seven charged pions and one or\nzero pizero mesons was performed using the BaBar detector at the PEP-II\nasymmetric-energy e+e- collider.\n The analysis uses 232.2 fb-1 of data at center-of-mass energies on or near\nthe Y(4S) resonance. We observe 24 events with an expected background of\n21.6+-1.3 events. Without evidence for a signal, we calculate an upper limit of\nBR(tau- --> 4pi- 3pi+ (pizero) nu_tau) < 3.0*10^-7 at 90 % confidence level.\n This is an improvement by nearly an order of magnitude over the previously\nestablished limit. In addition, we set upper limits for the exclusive decays\ntau- --> 4pi- 3pi+ nu_tau and tau- --> 4pi- 3pi+ pizero nu_tau.", "category": "hep-ex" }, { "text": "Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF\n Data Set: We report a measurement of the bottom-strange meson mixing phase \\beta_s\nusing the time evolution of B0_s -> J/\\psi (->\\mu+\\mu-) \\phi (-> K+ K-) decays\nin which the quark-flavor content of the bottom-strange meson is identified at\nproduction. This measurement uses the full data set of proton-antiproton\ncollisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment\nat the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity.\nWe report confidence regions in the two-dimensional space of \\beta_s and the\nB0_s decay-width difference \\Delta\\Gamma_s, and measure \\beta_s in [-\\pi/2,\n-1.51] U [-0.06, 0.30] U [1.26, \\pi/2] at the 68% confidence level, in\nagreement with the standard model expectation. Assuming the standard model\nvalue of \\beta_s, we also determine \\Delta\\Gamma_s = 0.068 +- 0.026 (stat) +-\n0.009 (syst) ps-1 and the mean B0_s lifetime, \\tau_s = 1.528 +- 0.019 (stat) +-\n0.009 (syst) ps, which are consistent and competitive with determinations by\nother experiments.", "category": "hep-ex" }, { "text": "Mixed higher-order anisotropic flow and nonlinear response coefficients\n of charged particles in PbPb collisions at $\\sqrt{s_\\mathrm{NN}} =$ 2.76 and\n 5.02 TeV: Anisotropies in the initial energy density distribution of the quark-gluon\nplasma created in high energy heavy ion collisions lead to anisotropies in the\nazimuthal distributions of the final-state particles known as collective flow.\nFourier harmonic decomposition is used to quantify these anisotropies. The\nhigher-order harmonics can be induced by the same order anisotropies (linear\nresponse) or by the combined influence of several lower order anisotropies\n(nonlinear response) in the initial state. The mixed higher-order anisotropic\nflow and nonlinear response coefficients of charged particles are measured as\nfunctions of transverse momentum and centrality in PbPb collisions at\nnucleon-nucleon center-of-mass energies $\\sqrt{s_\\mathrm{NN}} =$ 2.76 and 5.02\nTeV with the CMS detector. The results are compared with viscous hydrodynamic\ncalculations using several different initial conditions, as well as microscopic\ntransport model calculations. None of the models provides a simultaneous\ndescription of the mixed higher-order flow harmonics and nonlinear response\ncoefficients.", "category": "hep-ex" }, { "text": "Measurement of the $D^*(2010)^+ - D^+$ mass difference: We measure the mass difference, $\\Delta m_+$, between the $D^{*}(2010)^+$ and\nthe $D^+$ using the decay chain $D^{*}(2010)^+\\to D^+ \\pi^0$ with $D^+\\to\nK^-\\pi^+\\pi^+$. The data were recorded with the BABAR detector at\ncenter-of-mass energies at and near the $\\Upsilon(4S)$ resonance, and\ncorrespond to an integrated luminosity of approximately 468 ${\\rm fb}^{-1}$. We\nmeasure $\\Delta m_+ = \\left(140\\,601.0 \\pm 6.8[{\\rm stat}] \\pm 12.9[{\\rm\nsyst}]\\right)$ keV. We combine this result with a previous BABAR measurement of\n$\\Delta m_0\\equiv m(D^{*}(2010)^+) - m (D^0)$ to obtain $\\Delta m_D = m(D^+) -\nm(D^0) = \\left(4\\,824.9 \\pm 6.8[{\\rm stat}] \\pm 12.9[{\\rm syst}]\\right)$ keV.\nThese results are compatible with and approximately five times more precise\nthan the Particle Data Group averages.", "category": "hep-ex" }, { "text": "High Power Testing Results of the X-Band Mixed-Mode RF Windows for\n Linear Colliders: In this paper, we summarize the high power testing results of the X-band\nmixed-mode RF windows at KEK and SLAC for linear colliders. The main feature of\nthese windows is that the combination of modes on the surface of the ceramic\nsignificantly decreases the electric and magnetic fields in the junction\nbetween the ceramic and the metal. So far two types of high power windows (with\nthe diameter of 53 mm and 64 mm) have been fabricated. A high power model of\nthe smaller type window was fabricated and tested in a resonant ring at KEK. A\nmaximum circulating power of 81 MW with 300 ns duration or 66 MW with 700 ns\nduration was achieved. Light emission was observed for a power level of over 10\nMW. Later, both windows were shipped to SLAC for even higher power testing\nusing combined power from two klystrons. The first window (53 mm diameter)\nachieved a transmitted power of 80 MW with 1.5 microsec duration at 30 Hz\nrepetition. It was not destroyed during the testing. The testing of the second\nwindow was carried out next to the small type and achieved 62 MW with 1.5\nmaicrosec duration with 10 Hz repetition. The final results of both windows are\npresented in this report.", "category": "hep-ex" }, { "text": "Statistical combination of searches for the $\\rm{X^{\\pm}(5568)}$ state\n decaying into $\\rm{B^0_s \u03c0^\\pm}$: A statistical combination of the search results for the narrow\n$\\rm{X^{\\pm}(5568)}$ resonance decaying into $\\rm{B_s^0 \\pi^+}$ is reported,\nbased on published results from the ATLAS, CMS, CDF and LHCb Collaborations. A\nstructure in the invariant mass distribution of $\\rm{B_s^0 \\pi^+}$ has been\nobserved by the D0 Collaboration with a mass value of 5568 MeV but not\nconfirmed by any of the latest searches from the other Collaborations. Limits\nhave been set on the relative production rate $\\rm{\\rho_X}$ of the\n$\\rm{X^{\\pm}(5568)}$ and $\\rm{B^0_s}$ states, times the branching ratio for the\ndecay $\\rm{X^{\\pm}(5568) \\rightarrow B^0_s\\pi^\\pm}$.\n By applying a statistical combination of limits set by the three LHC\nexperiments, we derive a limit at 95\\% Confidence Level of $\\rho_X < 0.0092$\nfor $p_T(B^0_s)>$ 10 GeV, and $\\rho_X < 0.0091$ for $p_T(B^0_s)>$ 15 GeV,\nsuperseding the previous most stringent upper limits. The effect of including\nthe CDF result in the combination is also discussed.", "category": "hep-ex" }, { "text": "Hanohano:A Deep Ocean Antineutrino Observatory: This paper presents the science potential of a deep ocean antineutrino\nobservatory being developed at Hawaii and elsewhere. The observatory design\nallows for relocation from one site to another. Positioning the observaory some\n60 km distant from a nuclear reactor complex enables preecision measurement of\nneutrino mixing parameters, leading to a determination of neutrino mass\nhierarchy and theta_13. At a mid-Pacific location, the observatory measures the\nflux of uranium and thorium decay series antineutrinos from earth's mantle and\nperforms a sensitive search for a hypothetical natural fission reactor in\nearth's core. A subequent deployment at another mid-ocean location would test\nlateral homogeneity of uranium and thorium in earth's mantle. These\nmeasurements have significance for earth energy studies.", "category": "hep-ex" }, { "text": "Radiative decays of the Sigma0(1385) and Lambda(1520) hyperons: The electromagnetic decays of the Sig0(1385) and Lambda(1520) hyperons were\nstudied in photon-induced reactions gamma p -> K+ Lambda(1116)gamma in the CLAS\ndetector at the Thomas Jefferson National Accelerator Facility. We report the\nfirst observation of the radiative decay of the Sig0(1385) and a measurement of\nthe Lambda(1520) radiative decay width. For the Sig0(1385) -> Lambda(1116)gamma\ntransition, we measured a partial width of 479+/-120(stat)+81-100(sys) keV,\nlarger than all of the existing model predictions. For the Lambda(1520) ->\nLambda(1116)gamma transition, we obtained a partial width of\n167+/-43(stat)+26-12(sys) keV.", "category": "hep-ex" }, { "text": "Transverse Spin Effects at COMPASS: Single spin asymmetries in semi-inclusive deep-inelastic scattering off\ntransversely polarized nucleon targets have been under intense experimental\ninvestigation over the past few years. They provide new insights into QCD and\nthe nucleon structure. For instance, they allow the determination of the third\nyet-unknown leading-twist quark distribution function $\\Delta_{T}q(x)$, the\ntransversity distribution. Additionally, they give insight into the parton\ntransverse momentum distribution and angular momentum.\n The measurement of transverse spin effects in semi-inclusive deep-inelastic\nscattering is an important part of the COMPASS physics program. In the years\n2002-2004 data were collected scattering a 160 GeV muon beam on a transversely\npolarized deuteron target. In 2007, additional data were collected on a\ntransversely polarized proton target. New results from the analysis of the\nproton data will be presented. A different but not less important insight into\nthe nucleon structure might be given by the Sivers asymmetry. This angular\ndependence of the cross-section arises from an intrinsic asymmetry in the\nparton transverse momentum distribution. The Sivers function is tightly related\nto the total angular momentum carried by the quarks in the nucleon. New COMPASS\nresults for the Sivers asymmetry of the proton will be shown.", "category": "hep-ex" }, { "text": "Search for CP Violation in B0B0bar Mixing using Partial Reconstruction\n of B0-->D*-Xl+ nu and a Kaon Tag: We present results of a search for CP violation in B0B0bar mixing with the\nBABAR detector. We select a sample of B0-->D*-Xl+ nu decays with a partial\nreconstruction method and use kaon tagging to assess the flavor of the other B\nmeson in the event. We determine the CP violating asymmetry\n ACP = (N(B0B0) - N(B0bar B0bar))/(N(B0B0) + N(B0bar\nB0bar))=(0.06+-0.17+0.38-0.32)%, corresponding to delta_CP =1 - |q/p|\n=(0.29+-0.84+1.88 -1.61)*10^-3.", "category": "hep-ex" }, { "text": "Search for light mediators in the low-energy data of the CONNIE reactor\n neutrino experiment: The CONNIE experiment is located at a distance of 30 m from the core of a\ncommercial nuclear reactor, and has collected a 3.7 kg-day exposure using a CCD\ndetector array sensitive to an $\\sim$1 keV threshold for the study of coherent\nneutrino-nucleus elastic scattering. Here we demonstrate the potential of this\nlow-energy neutrino experiment as a probe for physics Beyond the Standard\nModel, by using the recently published results to constrain two simplified\nextensions of the Standard Model with light mediators. We compare the new\nlimits with those obtained for the same models using neutrinos from the\nSpallation Neutron Source. Our new constraints represent the best limits for\nthese simplified models among the experiments searching for CE$\\nu$NS for a\nlight vector mediator with mass $M_{Z^{\\prime}}<$ 10 MeV, and for a light\nscalar mediator with mass $M_{\\phi}<$ 30 MeV. These results constitute the\nfirst use of the CONNIE data as a probe for physics Beyond the Standard Model.", "category": "hep-ex" }, { "text": "Measurement of Diffractive Scattering of Photons with Large Momentum\n Transfer at HERA: The first measurement of diffractive scattering of quasi-real photons with\nlarge momentum transfer gamma p -> gamma Y, where Y is the proton dissociative\nsystem, is made using the H1 detector at HERA. The measurement is performed for\ninitial photon virtualities Q^2 < 0.01 GeV^2. Cross sections are measured as a\nfunction of W, the incident photon-proton entre of mass energy, and t, the\nsquare of the four-momentum transferred at the proton vertex, in the range 175\n< W < 247 GeV and 4<|t|<36 GeV^2. The W dependence is well described by a model\nbased on perturbative QCD using a leading logarithmic approximation of the BFKL\nevolution. The measured |t| dependence is harder than that predicted by the\nmodel and those observed in exclusive vector meson production.", "category": "hep-ex" }, { "text": "Study of fermion pair events at the 250 GeV ILC: Precise measurements of electroweak processes at the International Linear\nCollider (ILC) will provide unique opportunities to explore new physics beyond\nthe Standard Model. Fermion pair production events are sensitive to new\ninteractions involving a new heavy gauge boson or an electroweak interacting\nmassive particle (EWIMP).We studied the mass reach of new particles at the ILC\nwith $\\sqrt{s}=250$ GeV by using $e^+ e^-\\to e^+ e^-$and $e^+ e^-\\to \\mu^+\n\\mu^-$ events. We show that a mass reach for BSM particles can be determined\nwith 90% confidence level using a toy Monte Carlo technique.", "category": "hep-ex" }, { "text": "Measurement of the ratio of branching fractions\n $\\mathcal{B}(B_c^+\\,\\to\\,J/\u03c8\u03c4^+\u03bd_\u03c4)$/$\\mathcal{B}(B_c^+\\,\\to\\,J/\u03c8\u03bc^+\u03bd_\u03bc)$: A measurement is reported of the ratio of branching fractions\n$\\mathcal{R}(J/\\psi)=\\mathcal{B}(B_c^+\\,\\to\\,J/\\psi\\tau^+\\nu_\\tau)/\\mathcal{B}(B_c^+\\,\\to\\,J/\\psi\n\\mu^+\\nu_\\mu)$, where the $\\tau^+$ lepton is identified in the decay mode\n$\\tau^+\\,\\to\\,\\mu^+\\nu_\\mu\\overline{\\nu}_\\tau$. This analysis uses a sample of\nproton-proton collision data corresponding to 3.0$\\mathrm{\\,fb}^{-1}$ of\nintegrated luminosity recorded with the LHCb experiment at center-of-mass\nenergies $7\\,\\mathrm{TeV}$ and $8\\,\\mathrm{TeV}$. A signal is found for the\ndecay $B_c^+\\,\\to\\,J/\\psi \\tau^+\\nu_\\tau$ at a significance of 3 standard\ndeviations, corrected for systematic uncertainty, and the ratio of the\nbranching fractions is measured to be $\\mathcal{R}(J/\\psi) = 0.71 \\pm 0.17\n\\mathrm{\\,(stat)} \\pm 0.18\\mathrm{\\,(syst)}$. This result lies within 2\nstandard deviations above the range of existing predictions in the Standard\nModel.", "category": "hep-ex" }, { "text": "Search for exotic neutrino-electron interactions using solar neutrinos\n in XMASS-I: We have searched for exotic neutrino-electron interactions that could be\nproduced by a neutrino millicharge, by a neutrino magnetic moment, or by dark\nphotons using solar neutrinos in the XMASS-I liquid xenon detector. We observed\nno significant signals in 711 days of data. We obtain an upper limit for\nneutrino millicharge of 5.4$\\times$10$^{-12} e$ at 90\\% confidence level\nassuming all three species of neutrino have common millicharge. We also set\nflavor dependent limits assuming the respective neutrino flavor is the only one\ncarrying a millicharge, $7.3 \\times 10^{-12} e$ for $\\nu_e$, $1.1 \\times\n10^{-11} e$ for $\\nu_{\\mu}$, and $1.1 \\times 10^{-11} e$ for $\\nu_{\\tau}$.\nThese limits are the most stringent yet obtained from direct measurements. We\nalso obtain an upper limit for the neutrino magnetic moment of\n1.8$\\times$10$^{-10}$ Bohr magnetons. In addition, we obtain upper limits for\nthe coupling constant of dark photons in the $U(1)_{B-L}$ model of\n1.3$\\times$10$^{-6}$ if the dark photon mass is 1$\\times 10^{-3}$ MeV$/c^{2}$,\nand 8.8$\\times$10$^{-5}$ if it is 10 MeV$/c^{2}$.", "category": "hep-ex" }, { "text": "Searches for New Physics with leptons in the final state at the LHC: Final states including leptons are most promising to detect early signs of\nnew physics processes when the Large Hadron Collider will start proton-proton\ncollisions at the centre of mass energy of 14\\TeV. The reach for Supersymmetry\nand Extra Dimension models for integrated luminosities ranging from 1 to 10/fb\nis reported. Preliminary results indicate that already with 1/fb of data new\nphenomena can be detected.", "category": "hep-ex" }, { "text": "Searches for Point-like and extended neutrino sources close to the\n Galactic Centre using the ANTARES neutrino Telescope: A search for cosmic neutrino sources using six years of data collected by the\nANTARES neutrino telescope has been performed. Clusters of muon neutrinos over\nthe expected atmospheric background have been looked for. No clear signal has\nbeen found. The most signal-like accumulation of events is located at\nequatorial coordinates RA=$-$46.8$^{\\circ}$ and Dec=$-$64.9$^{\\circ}$ and\ncorresponds to a 2.2$\\sigma$ background fluctuation. In addition, upper limits\non the flux normalization of an E$^{-2}$ muon neutrino energy spectrum have\nbeen set for 50 pre-selected astrophysical objects. Finally, motivated by an\naccumulation of 7 events relatively close to the Galactic Centre in the\nrecently reported neutrino sample of the IceCube telescope, a search for point\nsources in a broad region around this accumulation has been carried out. No\nindication of a neutrino signal has been found in the ANTARES data and upper\nlimits on the flux normalization of an E$^{-2}$ energy spectrum of neutrinos\nfrom point sources in that region have been set. The 90% confidence level upper\nlimits on the muon neutrino flux normalization vary between 3.5 and\n5.1$\\times$10$^{-8}$ GeV$\\,$cm$^{-2}$s$^{-1}$, depending on the exact location\nof the source.", "category": "hep-ex" }, { "text": "Projected Sensitivity of DMRadio-m$^3$: A Search for the QCD Axion Below\n $1\\,\u03bc$eV: The QCD axion is one of the most compelling candidates to explain the dark\nmatter abundance of the universe. With its extremely small mass ($\\ll\n1\\,\\mathrm{eV}/c^2$), axion dark matter interacts as a classical field rather\nthan a particle. Its coupling to photons leads to a modification of Maxwell's\nequations that can be measured with extremely sensitive readout circuits.\nDMRadio-m$^3$ is a next-generation search for axion dark matter below\n$1\\,\\mu$eV using a $>4$ T static magnetic field, a coaxial inductive pickup, a\ntunable LC resonator, and a DC-SQUID readout. It is designed to search for QCD\naxion dark matter over the range $20\\,\\mathrm{neV}\\lesssim m_ac^2\\lesssim\n800\\,\\mathrm{neV}$ ($5\\,\\mathrm{MHz}<\\nu<200\\,\\mathrm{MHz}$). The primary\nscience goal aims to achieve DFSZ sensitivity above $m_ac^2\\approx 120$ neV (30\nMHz), with a secondary science goal of probing KSVZ axions down to\n$m_ac^2\\approx40\\,\\mathrm{neV}$ (10 MHz).", "category": "hep-ex" }, { "text": "Measurement of W-Boson Helicity Fractions in Top-Quark Decays Using\n costheta*: Fully reconstructed top-antitop-events are used to determine the fractions of\nright-handed and longitudinally polarized W bosons produced in top-quark\ndecays. The helicity fractions are sensitive to the couplings and the Dirac\nstructure of the Wtb vertex. This paper reports measurements of the W-boson\nhelicity fractions from two different methods using data corresponding to an\nintegrated luminosity of 1.9 fb-1 of proton-antiproton collisions collected by\nthe CDF II detector operating at the Fermilab Tevatron.", "category": "hep-ex" }, { "text": "DsTau: Study of tau neutrino production with 400 GeV protons from the\n CERN-SPS: In the DsTau experiment at the CERN SPS, an independent and direct way to\nmeasure tau neutrino production following high energy proton interactions was\nproposed. As the main source of tau neutrinos is a decay of Ds mesons, produced\nin proton-nucleus interactions, the project aims at measuring a differential\ncross section of this reaction. The experimental method is based on a use of\nhigh resolution emulsion detectors for effective registration of events with\nshort lived particle decays. Here we present the motivation of the study,\ndetails of the experimental technique, and the first results of the analysis of\nthe data collected during test runs, which prove feasibility of the full scale\nstudy of the process in future.", "category": "hep-ex" }, { "text": "Recent Progress on Charmonium Decays at BESIII: In 2009, the BESIII experiment has collected about 225M $\\jpsi$ and 106M\n$\\psip$ samples, both of which are the world largest on-peak charmonium\nproduction. Based on these dataset, BESIII has made great effort on the study\nof the charmonium decays, some important of which have been reviewed in this\nproceeding. In addition, a searching for new physics through the $CP/P$\nviolation process is reported.", "category": "hep-ex" }, { "text": "Partial Wave Analysis of $J/\u03c8\\rightarrow \u03b3\u03b3\u03c6$: Using a sample of $(10087\\pm44)\\times10^{6}$ $J/\\psi$ events collected with\nthe BESIII detector at the BEPCII collider, a partial wave analysis on the\ndecay $\\gamma\\gamma\\phi$ is performed to investigate the intermediate\nresonances in $J/\\psi\\rightarrow\\gamma X, X\\rightarrow\\gamma\\phi$. The\nresonances $f_{1}(1285)$, $\\eta(1405)$, $f_{1}(1420)$, $f_{1}(1510)$,\n$f_{2}(1525)$, $X(1835)$, $f_{2}(1950)$, $f_{2}(2010)$, $f_{0}(2200)$ and\n$\\eta_{c}$ are observed with statistical significance greater than 5$\\sigma$.\nThe product branching fractions $\\mathcal{B}(J/\\psi\\rightarrow\\gamma X,\nX\\rightarrow \\gamma \\phi)$ are reported. The resonance parameters of\n$\\eta(1405)$ and $X(1835)$ are also measured.", "category": "hep-ex" }, { "text": "Amplitude analysis of e+e- => Y(nS)pi+pi- at sqrt(s)=10.865 GeV: We report results on studies of the e+e- annihilation into three-body\nY(nS)pi+pi- (n=1,2,3) final states including measurements of cross sections and\nthe full amplitude analysis. The cross sections measured at sqrt(s)=10.865 GeV\nand corrected for the initial state radiation are\nsigma(e+e-=>Y(1S)pi+pi-)=(2.27+-0.12+-0.14) pb,\nsigma(e+e-=>Y(2S)pi+pi-)=(4.07+-0.16+-0.45) pb, and\nsigma(e+e-=>Y(3S)pi+pi-)=(1.46+-0.09+-0.16) pb. Amplitude analysis of the\nthree-body Y(nS)pi+pi- final states strongly favors I^G(J^P)=1^+(1^+)\nquantum-number assignments for the two bottomonium-like Zb+- states, recently\nobserved in the Y(nS)pi+- and hb(mP)pi+- (m=1,2) decay channels. The results\nare obtained with a $121.4 1/fb data sample collected with the Belle detector\nat the KEKB asymmetric-energy e+e- collider.", "category": "hep-ex" }, { "text": "Key4hep, a framework for future HEP experiments and its use in FCC: The road map to the FCC Feasibility Study Report, for submission to the next\nUpdate of the European Strategy for Particle Physics, will require detailed\nsimulation and advanced reconstruction algorithms to explore and maximise the\nphysics reach of proposed detector solutions. The optimisation process will\nrequire maximal flexibility in changing detector geometries, materials and\nsensitive areas, and efficient tools to quantify the overall performance. To\nsynergise such developments the CEPC, CLIC, FCC, ILC and SCT communities have\nengaged in the commissioning of a `Turnkey Software Stack' (Key4hep), which\nwould provide all the necessary ingredients, from simulation to analysis, for\nfuture experiments. This approach is based on the positive experience of the\nlinear collider projects ILC and CLIC, which have developed and used a common\nsoftware stack (iLCSoft) over the last decade. Key4hep aims to cover most, if\nnot all, future linear and circular machines colliding leptons (electrons,\nmuons), and hadrons. The common software ecosystem will facilitate writing\nspecific components for experiments ensuring coherency and maximising the\nre-use of established solutions. Project-specific software frameworks will\nrequire adaptation to fully profit from the common software base. In this essay\nwe present the status and plans for re-framing the FCC software framework,\nFCCSW, around Key4hep and discuss the challenges associated with the\ntransition.", "category": "hep-ex" }, { "text": "Tau Lepton Production in ep Collisions at HERA: The production of tau leptons in ep collisions is investigated using data\nrecorded by the H1 detector at HERA in the period 1994-2000. Tau leptons are\nidentified by detecting their decay products, using leptonic and hadronic decay\nmodes. The cross section for the production of tau lepton pairs is measured for\nthe first time at HERA. Furthermore, a search for events with an energetic\nisolated tau lepton and with large missing transverse momentum is performed.\nThe results are found to be in agreement with the Standard Model predictions.", "category": "hep-ex" }, { "text": "The Q^2-dependence of the Generalised Gerasimov-Drell-Hearn Integral for\n the Proton: The dependence on Q^2 (the negative square of the 4-momentum of the exchanged\nvirtual photon) of the generalised Gerasimov-Drell-Hearn integral for the\nproton has been measured in the range 1.2 GeV^2 < Q^2 < 12 GeV^2 by scattering\nlongitudinally polarised positrons on a longitudinally polarised hydrogen gas\ntarget. The contributions of the nucleon-resonance and deep-inelastic regions\nto this integral have been evaluated separately. The latter has been found to\ndominate for Q^2 > 3 GeV^2, while both contributions are important at low Q^2.\nThe total integral shows no significant deviation from a 1/Q^2 behaviour in the\nmeasured Q^2 range, and thus no sign of large effects due to either\nnucleon-resonance excitations or non-leading twist.", "category": "hep-ex" }, { "text": "Search for inclusive charmless B->K+X and B->K0X decays: We present preliminary results from a search for inclusive charmless B->KX\ndecays. These decays occur dominantly via one-loop b->s penguin transitions,\nand can provide useful information about these processes. Using a sample of\n288.5/fb collected with the BABAR detector at the PEP-II asymmetric-energy e+e-\nB Factory at SLAC, we search for high-energy kaons recoiling against fully\nreconstructed B decays. We measure the partial branching fractions for kaons\nwith momentum p*(K)>2.34GeV in the B rest frame, and obtain (in units of\n10^-6): B(B->K+X, p*>2.34GeV) = 196^{+37}_{-34}(stat.)^{+31}_{-30}(syst.) and\nB(B->K0X, p*>2.34GeV) = 154^{+55}_{-48}(stat.)^{+55}_{-41}(syst.) (<266 at 90%\nC.L.).", "category": "hep-ex" }, { "text": "Semileptonic B / Bs decays at Belle: The Belle experiment at the KEKB asymmetric energy e+e- collider recorded\nlarge data sets of both, B and Bs decays. Semileptonic decays B(s) -> X l nu (l\n= electron or muon) constitute approximately one fifth of the total decay width\nof B(s) mesons and play an important role in the determination of the CKM\nmatrix elements V_ub and V_cb. Recent results from Belle are presented,\nincluding the study of B- -> Ds(*) K l nu, the first measurements of\nsemi-inclusive modes B -> D(*) X l nu and the measurement of the inclusive\nbranching fraction Bf(Bs -> X l nu).", "category": "hep-ex" }, { "text": "Search for exotic resonances decaying into WZ/ZZ in pp collisions at\n sqrt(s) = 7 TeV: A search for new exotic particles decaying to the VZ final state is\nperformed, where V is either a W or a Z boson decaying into two overlapping\njets and the Z decays into a pair of electrons, muons or neutrinos. The\nanalysis uses a data sample of pp collisions corresponding to an integrated\nluminosity of 5 inverse femtobarns collected by the CMS experiment at the LHC\nat sqrt(s) = 7 TeV in 2011. No significant excess is observed in the mass\ndistribution of the VZ candidates compared with the background expectation from\nstandard model processes. Model-dependent upper limits at the 95% confidence\nlevel are set on the product of the cross section times the branching fraction\nof hypothetical particles decaying to the VZ final state as a function of mass.\nSequential standard model W' bosons with masses between 700 and 940 GeV are\nexcluded. In the Randall-Sundrum model for graviton resonances with a coupling\nparameter of 0.05, masses between 750 and 880 GeV are also excluded.", "category": "hep-ex" }, { "text": "A biased MC for muon production for beam-dump experiments: The search for feebly-interacting new-physics particles in the MeV-GeV mass\nrange often involves high-intensity beams dumped into thick heavy targets. The\nchallenge of evaluating the expected backgrounds for these searches from first\nprinciples is limited by the CPU time needed to generate the shower induced by\nthe primary beam. We present a Monte Carlo biasing method allowing a three\norders of magnitude increase in the efficiency for the simulation of the muon\nproduction in a 400 GeV$/c$ proton beam-dump setup. At the same time, this\nbiasing method is maintaining nearly every feature of a simulation from first\nprinciples.", "category": "hep-ex" }, { "text": "Topological heavy-flavor tagging and intrinsic bottom at the\n Electron-Ion Collider: Heavy-flavor hadron production, in particular bottom hadron production, is\ndifficult to study in deep-inelastic scattering (DIS) experiments due to small\nproduction rates and branching fractions. To overcome these limitations, a\nmethod for identifying heavy-flavor DIS events based on event topology is\nproposed. Based on a heavy-flavor jet tagging strategy developed for the LHCb\nexperiment, this algorithm uses displaced vertices to identify decays of\nheavy-flavor hadrons. The algorithm's performance at the Electron-Ion Collider\nis demonstrated using simulation, and it is shown to provide discovery\npotential for non-perturbative intrinsic bottom quarks in the proton.", "category": "hep-ex" }, { "text": "Prompt Photon Production at HERA and LEP: Results on isolated prompt photon production are presented. The measurements\nwere performed at HERA in deep inelastic ep scattering and photoproduction, as\nwell as at LEP in photon photon collisions. Differential cross sections are\nshown for inclusive prompt photons and those accompanied by a jet. The results\nare compared to predictions of perturbative QCD calculations in next to leading\norder and to predictions of the event generators PYTHIA and HERWIG.", "category": "hep-ex" }, { "text": "Results on Charmonium-like States at BaBar: We present recent results on charmonium and charmonium-like states from the\nBaBar B-factory located at the PEP-II asymmetric energy $e^{+}e^{-}$ storage\nring at the SLAC National Accelerator Laboratory.", "category": "hep-ex" }, { "text": "Measuring the W boson mass at the Tevatron: The measurement of the mass of the W boson is one of the prime goals of the\nTevatron experiments. In this contribution, a review is given of the most\nrecent determinations of the W boson mass (mW) at the Tevatron. The combined\nTevatron result, mW = 80.420 +/- 0.031 GeV, is now more precise than the\ncombined LEP result, leading to a world average value of mW = 80.399 +/- 0.023\nGeV.", "category": "hep-ex" }, { "text": "Direct Measurements of the Branching Fractions for the Semileptonic\n Decays $D^0 \\to K^-\u03bc^+\u03bd_\u03bc$ and $D^0 \\to \u03c0^-\u03bc^+\u03bd_\u03bc$: Based on the data sample of 33 pb$^{-1}$ collected at and around 3.773 GeV\nwith the BES-II detector at the BEPC collider, the absolute branching fractions\nfor the semileptonic decays $D^0\\to K^-\\mu^+\\nu_\\mu$ and\n$D^0\\to\\pi^-\\mu^+\\nu_\\mu$ have been measured. In the system recoiling against\n$7584\\pm198\\pm341$ singly tagged $\\bar D^0$ mesons, $87.2\\pm13.6$ events for\n$D^0\\to K^-\\mu^+\\nu_\\mu$ and $9.3\\pm7.4$ events for $D^0\\to\\pi^-\\mu^+\\nu_\\mu$\nare observed. These yield the absolute branching fractions to be $BF(D^0\\to\nK^-\\mu ^+\\nu_\\mu)= (3.55\\pm0.56\\pm0.59)%$ and $BF(D^0\\to\\pi^-\\mu^+\\nu_\\mu)=\n(0.38\\pm0.30\\pm0.10)%$. The measured branching fraction for $D^0\\to K^-\\mu\n^+\\nu_\\mu$ was previously used to determine the ratio $\\Gamma(D^0\\to\nK^-\\mu^+\\nu_\\mu)/ \\Gamma(D^+\\to \\bar K^0\\mu^+\\nu_\\mu)$ combining the previously\nmeasured branching fraction for $D^+\\to \\bar K^0\\mu^+\\nu_\\mu$ by the BES\nCollaboration.", "category": "hep-ex" }, { "text": "Experimental Search for Chargino and Neutralino Production in\n Supersymmetry Models with a Light Gravitino: We search for inclusive high $E_T$ diphoton events with large missing\ntransverse energy in $p\\bar{p}$ collisions at $\\sqrt{s}$=1.8 TeV. Such events\nare expected from pair production of charginos and neutralinos within the\nframework of the minimal supersymmetric standard model with a light gravitino.\nNo excess of events is observed. In that model, and assuming gaugino mass\nunification at the GUT scale, we obtain a 95% CL exclusion region in the\nsupersymmetry parameter space and lower mass bounds of 150 GeV/c$^2$ for the\nlightest chargino and 75 GeV/c$^2$ for the lightest neutralino.", "category": "hep-ex" }, { "text": "New Search for tau -> mu gamma and tau -> e gamma Decays at Belle: We report on a search for the lepton flavor violating tau- -> mu- gamma and\ntau- -> e- gamma decays based on 535/fb of data accumulated at the Belle\nexperiment. No signal is found and we set 90% confidence level upper limits on\nthe branching ratios Br(tau- -> mu- gamma) < 4.5x10^-8 and Br(tau- -> e- gamma)\n< 1.2x10^-7.", "category": "hep-ex" }, { "text": "CLEO Results on Transitions in Heavy Quarkonia: Recent CLEO results on electromagnetic and hadronic transitions in charmonium\nand bottomonium systems are reviewed.", "category": "hep-ex" }, { "text": "Measurement of the ttbar cross section using high-multiplicity jet\n events: We present a measurement of the ttbar cross section using high-multiplicity\njet events produced in ppbar collisions at sqrt{s}=1.96 TeV. These data were\nrecorded at the Fermilab Tevatron collider with the D0 detector. Events with at\nleast six jets, two of them identified as b jets, were selected from a 1 fb-1\ndata set. The measured cross section, assuming a top quark mass of 175 GeV/c^2,\nis 6.9 \\pm 2.0 pb, in agreement with theoretical expectations.", "category": "hep-ex" }, { "text": "Electron - Dark Matter Scattering in an Evacuated Tube: The light dark matter model can explain both the primordial abundance of dark\nmatter and the anomalous 511 keV gamma-ray signal from the galactic center.\nThis model posits a light neutral scalar, \\chi, with a mass in the range 1 MeV\n< Mchi < 10 MeV, as well as a light neutral spin-1 boson, U, which mediates the\nannihilation channel \\chi\\chi -> e+e-. Since the dark matter particle is light,\nits number density is relatively large if it accounts for a local dark matter\ndensity of 0.3 GeV/cm^3. We consider an experiment in which a low-energy,\nhigh-current electron beam is passed through a long evacuated tube, and elastic\nscattering of electrons off dark matter particles is observed. The kinematics\nof this process allow a clean separation of the signal process from scattering\noff residual gas in the tube, and also a direct measurement of Mchi.", "category": "hep-ex" }, { "text": "Observation of a vector charmoniumlike state at 4.7 ${\\rm GeV}/c^2$ and\n search for $Z_{cs}$ in $e^+e^-\\to K^+K^-J/\u03c8$: Using data samples with an integrated luminosity of 5.85~fb$^{-1}$ collected\nat center-of-mass energies from 4.61 to 4.95 GeV with the BESIII detector\noperating at the BEPCII storage ring, we measure the cross section for the\nprocess $e^+e^-\\to K^+K^-J/\\psi$. A new resonance with a mass of $M =\n4708_{-15}^{+17}\\pm21$ MeV/$c^{2}$ and a width of $\\Gamma =\n126_{-23}^{+27}\\pm30$ MeV is observed in the energy-dependent line shape of the\n$e^+e^-\\to K^+K^-J/\\psi$ cross section with a significance over $5\\sigma$. The\n$K^{+}J/\\psi$ system is also investigated to search for charged charmoniumlike\nstates, but no significant $Z_{cs}^+$ states are observed. Upper limits on the\nBorn cross sections for $e^+e^-\\to K^{-} Z_{cs}(3985)^{+}/K^{-}\nZ_{cs}(4000)^{+} + c.c.$ with $Z_{cs}(3985)^{\\pm}/Z_{cs}(4000)^{\\pm}\\to K^{\\pm}\nJ/\\psi$ are reported at 90\\% confidence levels. The ratio of branching\nfractions $\\frac{\\mathcal{B}(Z_{cs}(3985)^{+}\\to K^+\nJ/\\psi)}{\\mathcal{B}(Z_{cs}(3985)^{+}\\to (\\bar{D}^{0}D_s^{*+} +\n\\bar{D}^{*0}D_s^+))}$ is measured to be less than 0.03 at 90\\% confidence\nlevel.", "category": "hep-ex" }, { "text": "Top quark mass and properties in ATLAS and CMS: For standard model (SM) processes involving top quarks, such as top\nquark-antiquark pair production or single top quark production, the theoretical\npredictions depend on fundamental parameters of the SM like the top quark mass.\nUsing the large data sample collected at the CERN LHC in the second data-taking\nperiod by the ATLAS and CMS experiments, these parameters can be extracted in\nexperimental measurements with high precision. Furthermore, properties of the\nproduction processes such as quark polarization or asymmetries can be measured.\nExploiting the large luminosity of the data set, new kinematic regimes and\nmethods are explored, as for events in which the top quarks have a very large\ntransverse momentum. In these proceedings, recent measurements of SM parameters\nand top quark properties are presented. Individual results are also interpreted\nin terms of effective field theory extensions of the SM.", "category": "hep-ex" }, { "text": "Direct Measurement of the Pseudoscalar Decay Constant fD+: The absolute branching fraction of $D^+ \\to \\mu^+ \\nu$ has been directly\nmeasured by an analysis of a data sample of about 33 ${\\rm pb^{-1}}$ collected\naround $\\sqrt{s}=3.773$ GeV with the BES-II at the BEPC. At these energies,\n$D^-$ meson is produced in pair as $e^+e^-\\to D^{+} D^{-}$. A total of $5321\n\\pm 149 \\pm 160$ $D^-$ mesons are reconstructed from this data set. In the\nrecoil side of the tagged $D^-$ mesons, $2.67\\pm1.74$ purely leptonic decay\nevents of $D^+ \\to \\mu^+ \\nu$ are observed. This yields a branching fraction of\n$BF(D^+ \\to \\mu^+ \\nu_{\\mu}) = (0.122^{+0.111}_{-0.053}\\pm 0.010)%$, and a\ncorresponding pseudoscalar decay constant $f_{D^+}=(371^{+129}_{-119}\\pm 25)$\nMeV.", "category": "hep-ex" }, { "text": "Experimental study of direct photon emission in K- --> pi- pi0 gamma\n decay using ISTRA+ detector: The branching ratio in the charged-pion kinetic energy region of 55 to 90 MeV\nfor the direct photon emission in the K- --> pi- pi0 gamma decay has been\nmeasured using in-flight decays detected with the ISTRA+ setup operating in the\n25 GeV/c negative secondary beam of the U-70 PS. The value\nBr(DE)=[0.37+-0.39(stat)+-0.10(syst)]*10^(-5) obtained from the analysis of 930\ncompletely reconstructed events is consistent with the average value of two\nstopped-kaon experiments, but it differs by 2.5 standard deviations from the\naverage value of three in-flight-kaon experiments. The result is also compared\nwith recent theoretical predictions.", "category": "hep-ex" }, { "text": "Search for Light Dark Matter-Electron Scatterings in the PandaX-II\n Experiment: We report constraints on light dark matter through its interactions with\nshell electrons in the PandaX-II liquid xenon detector with a total 46.9\ntonne$\\cdot$day exposure. To effectively search for these very low energy\nelectron recoils, ionization-only signals are selected from the data. 1821\ncandidates are identified within ionization signal range between 50 to 75\nphotoelectrons, corresponding to a mean electronic recoil energy from 0.08 to\n0.15 keV. The 90% C.L. exclusion limit on the scattering cross section between\nthe dark matter and electron is calculated based on Poisson statistics. Under\nthe assumption of point interaction, we provide the world's most stringent\nlimit within the dark matter mass range from 15 to 30 $\\rm MeV/c^2$, with the\ncorresponding cross section from $2.5\\times10^{-37}$ to $3.1\\times10^{-38}$\ncm$^2$.", "category": "hep-ex" }, { "text": "Hidden Charm Spectroscopy from Tevatron: The observation of a narrow structure near the J/psi phi threshold in\nexclusive B+ to J/psi phi K+ decays produced in p-pbar collisions at sqrt(s) =\n1.96 TeV is reported. A signal of 19 +- 6(stat) +- 3(syst) events, with\nstatistical significance of 5.0 standard deviations, is seen in a data sample\ncorresponding to an integrated luminosity of 6.0 invfb, collected by the CDF II\ndetector. The mass and natural width of the structure are determined to be m =\n4143.4 + 2.9 - 3.0(stat) +- 0.6(syst) MeV and Gamma = 15.3 + 10.4 - 6.1(stat)\n+- 2.5(syst) MeV, consistent with the previous measurements reported as\nevidence of the Y(4140).", "category": "hep-ex" }, { "text": "Exclusive $\u03c1^{0}$ Production in Polarized DIS at SMC: Preliminary spin cross section asymmetries for exclusive $\\rho^{0}$\nlepto-production, $\\vec{\\mu} + \\vec{N} \\to \\mu' + N + \\rho^{0} (\\rho^{0} \\to\n\\pi^{+} \\pi^{-})$, are reported. These asymmetries have been determined for the\nfirst time by the Spin Muon Collaboration (SMC) at low Q^2 (photoproduction)\nand at large Q^2 (DIS) for different $p_T^2$ intervals in the kinematic range\n$0.01 \\simeq 15 GeV) for the\nfull SMC data set. About 100 K $\\rho^{0}$'s have been selected for $0.62 < m\n(\\pi^{+} \\pi^{-}) < 1.07 GeV/c^2$ and $|I|< 0.05$. Within the statistical\nprecision, no significant asymmetries have been observed at low $Q^{2}$ in the\npreliminary results.", "category": "hep-ex" }, { "text": "Resonances in the System of Pi+Pi- -- Mesons from the Reaction\n np->npPi+Pi- at Pn=5.20GeV/c: Search, Results of Direct Observations,\n Interpretation: Ten resonances were found in the mass spectrum of pi+pi- -system from the\nreaction np->nppi+pi- in np-interactions at Pn=5.20 GeV/c in the 1-m HBC of LHE\nJINR by using the criterion cos(teta)[c.m.c.] p>0. Such effects were not found\nin pi-pi0 - combinations from the reaction np->pppi-pi0. Therefore, it is\nnecessary to attribute the value of isotopic spin I = 0 to the resonances found\nin the mass spectrum of the pi+pi- -system. The spin was estimated for the most\nstatistically provided resonances. We determine with a high degree of\nconfidence that J = 0 for the resonances at MR = 757 MeV/c^2 and MR = 418\nMeV/c^2. Therefore, it can be affirmed that at least 3 states with quantum\nnumbers of sigma0-meson 0+(0++) have been found at masses of 418, 511 and 757\nMeV/c^2. The fact low-mass sigma0-mesons are glueballs is one of the possible\ninterpretations. The comparison with the data of other papers has also been\nmade. The investigation has been performed at the Veksler and Baldin Laboratory\nof High Energies,JINR.", "category": "hep-ex" }, { "text": "First Probe of Sub-GeV Dark Matter Beyond the Cosmological Expectation\n with the COHERENT CsI Detector at the SNS: The COHERENT collaboration searched for scalar dark matter particles produced\nat the Spallation Neutron Source with masses between 1 and 220~MeV/c$^2$ using\na CsI[Na] scintillation detector sensitive to nuclear recoils above\n9~keV$_\\text{nr}$. No evidence for dark matter is found and we thus place\nlimits on allowed parameter space. With this low-threshold detector, we are\nsensitive to coherent elastic scattering between dark matter and nuclei. The\ncross section for this process is orders of magnitude higher than for other\nprocesses historically used for accelerator-based direct-detection searches so\nthat our small, 14.6~kg detector significantly improves on past constraints. At\npeak sensitivity, we reject the flux consistent with the cosmologically\nobserved dark-matter concentration for all coupling constants $\\alpha_D<0.64$,\nassuming a scalar dark-matter particle. We also calculate the sensitivity of\nfuture COHERENT detectors to dark-matter signals which will ambitiously test\nmultiple dark-matter spin scenarios.", "category": "hep-ex" }, { "text": "The Nuclear Emulsion Technology and the Analysis of the OPERA Experiment\n Data: OPERA is an experiment that aims at detecting the appearance of tau-neutrino\nin an almost pure mu-neutrino beam (the CNGS neutrino beam) through\noscillation. OPERA is a hybrid detector that associates nuclear emulsions to\nelectronic detectors. The nuclear emulsion provides the resolution necessary to\ndetect tau-neutrino CC interactions. The first physics run started in July and\nended in November 2008. In this presentation, the status of the emulsion\ntechnology and of the analysis of its data is reported.", "category": "hep-ex" }, { "text": "Charmless B Decays Involving Vector Mesons in Belle: Using the data sample of 10.5 fb-1 collected by the Belle detector, we\nsearched for two-body charmless decays involving vector mesons. The clear\nsignal signature of B+ -> phi K+ is seen and its branching fraction is measured\nto be (1.39+.32-.30 +- 0.2) X 10-5. The evidence for B+ -> rho pi+, B0 -> rho-\npi+ and B+ -> phi K*+ is reported and their branching fractions are determined.\nNo significant signals are observed for B0 -> phi K0S, -> phi K*0, -> rho- K+,\nB+ -> rho K+, -> omega pi+ and -> omega K+ only the 90% C.L. upper limits are\ngiven.", "category": "hep-ex" }, { "text": "Determination of the strong coupling constant using subjet\n multiplicities in Neutral Current Deep Inelastic Scattering: The internal structure of the jets produced in neutral current interactions\nfor Q^2>125 GeV^2 has been studied using the subjet multiplicity with the ZEUS\ndetector at HERA. Jets are identified in the laboratory frame by applying the\nlongitudinally invariant k_T-cluster algorithm. Next-to-leading order QCD\ncalculations have been obtained and compared to the data; a good agreement has\nbeen observed in the region where hadron-to-parton corrections are small,\nE_{T,jet}> 25 GeV. In this region, the strong coupling constant is extracted\nand the resulting value is alpha_s (M_Z)=0.1185 +/- 0.0016 (stat.)\n^{+0.0067}_{-0.0048} (syst.) ^{+0.0089}_{-0.0071} (th.).", "category": "hep-ex" }, { "text": "Measurement of the Ratio of Partial Branching Fractions of Inclusive\n $\\overline{B} \\to X_u \\ell \\overline\u03bd$ to $\\overline{B} \\to X_{c} \\ell\n \\overline\u03bd$ and the Ratio of their Spectra with Hadronic Tagging: We present a measurement of the ratio of partial branching fractions of the\nsemi-leptonic inclusive decays, $\\overline{B} \\to X_{u} \\ell \\overline{\\nu}$ to\n$\\overline{B} \\to X_{c} \\ell \\overline{\\nu}$, where $\\ell = (e, \\mu)$, using\nthe full Belle sample of $772 \\times 10^{6}$ $B \\kern 0.18em\\overline{\\kern\n-0.18em B}$ pairs collected at the $\\Upsilon(4S)$ resonance. The ratio is\nmeasured via a two-dimensional fit to the squared four-momentum transfer to the\nlepton pair, and the charged lepton energy in the $B$ meson rest frame, where\nthe latter must be larger than $1$ Ge\\kern -0.1em V, covering approximately\n$86\\%$ and $78\\%$ of the $\\overline{B} \\to X_{u} \\ell \\overline{\\nu}$ and\n$\\overline{B} \\to X_{c} \\ell \\overline{\\nu}$ phase space, respectively. We find\n$\\Delta \\mathcal{B}(\\overline{B} \\to X_{u} \\ell \\overline{\\nu})/ \\Delta\n\\mathcal{B}(\\overline{B} \\to X_{c} \\ell \\overline{\\nu}) = 0.0196(1 \\pm\n8.4\\%_{\\rm stat} \\pm 7.9\\%_{\\rm syst})$ where the uncertainties are statistical\nand systematic, respectively. In addition, we report the partial branching\nfractions separately for charged and neutral $B$ meson decays, and for electron\nand muon decay channels. We place a limit on isospin breaking in $\\overline{B}\n\\to X_{u} \\ell \\overline{\\nu}$ decays, and find no indication of lepton flavor\nuniversality violation in either the charmed or charmless mode. Furthermore, we\nunfold the $\\overline{B} \\to X_{u} \\ell \\overline{\\nu}$ and $\\overline{B} \\to\nX_{c} \\ell \\overline{\\nu}$ yields and report the differential ratio in lepton\nenergy and four-momentum transfer squared.", "category": "hep-ex" }, { "text": "Search for Single Top Production in e+e- Collisions at sqrt(s) up to\n 209GeV: Single top production via the flavour changing neutral current reactions e+e-\n-> \\bar{t}c, \\bar{t}u is searched for within the 214 pb-1 of data collected by\nALEPH at centre-of-mass energies between 204 and 209 GeV. No deviation from the\nStandard Model expectation is observed and upper limits on the single top\nproduction cross sections are derived. The combination with data collected at\nlower centre-of-mass energies yields an upper limit on the branching ratio BR(t\n-> Zc)+BR(t -> Zu) 14%, for BR(t -> \\gamma c)+BR(t -> \\gamma u)= 0 and mt=174\nGeV/c2.", "category": "hep-ex" }, { "text": "Search for a heavy charged boson in events with a charged lepton and\n missing transverse momentum from $pp$ collisions at $\\sqrt{s} = 13$ TeV with\n the ATLAS detector: A search for a heavy charged-boson resonance decaying into a charged lepton\n(electron or muon) and a neutrino is reported. A data sample of 139 fb$^{-1}$\nof proton-proton collisions at $\\sqrt{s} = 13$ TeV collected with the ATLAS\ndetector at the LHC during 2015-2018 is used in the search. The observed\ntransverse mass distribution computed from the lepton and missing transverse\nmomenta is consistent with the distribution expected from the Standard Model,\nand upper limits on the cross section for $pp \\to W^\\prime \\to \\ell\\nu$ are\nextracted ($\\ell = e$ or $\\mu$). These vary between 1.3 pb and 0.05 fb\ndepending on the resonance mass in the range between 0.15 and 7.0 TeV at 95%\nconfidence level for the electron and muon channels combined. Gauge bosons with\na mass below 6.0 TeV and 5.1 TeV are excluded in the electron and muon\nchannels, respectively, in a model with a resonance that has couplings to\nfermions identical to those of the Standard Model $W$ boson. Cross-section\nlimits are also provided for resonances with several fixed $\\Gamma / m$ values\nin the range between 1% and 15%. Model-independent limits are derived in\nsingle-bin signal regions defined by a varying minimum transverse mass\nthreshold. The resulting visible cross-section upper limits range between 4.6\n(15) pb and 22 (22) ab as the threshold increases from 130 (110) GeV to 5.1\n(5.1) TeV in the electron (muon) channel.", "category": "hep-ex" }, { "text": "Evidence for the decay $\u03a5(4S) \\to \u03a5(1S) \u03c0^{+} \u03c0^{-} $: A study of transitions between $\\Upsilon$ states with the emission of charged\npions using 398 fb$^{-1}$ of data collected with the Belle detector at the KEKB\nasymmetric energy $e^+e^-$ collider is presented. A clear peak from the decay\n$\\Upsilon(1S)\\to\\mu^+\\mu^-$ is observed in the invariant mass distribution of\n$(\\mu^+ \\mu^-)$ pairs from the $(\\mu^+ \\mu^- \\pi^+ \\pi^- X)$ event sample. The\nmass difference distribution ($M_{\\mu^+\\mu^-\\pi^+\\pi^-}-M_{\\mu^+\\mu^-}$) for\n$M_{\\mu^+\\mu^-}$ from the $\\Upsilon(1S)$ mass region has two peaks from\n$\\Upsilon(2S,3S)\\to \\Upsilon(1S)\\pi^+\\pi^-$ decays, with no background. A third\npeak at $\\Delta M = (1119.0\\pm 1.4)$~MeV/$c^2$ can be interpreted as evidence\nof a signal from the decay $\\Upsilon(4S)\\to \\Upsilon(1S)\\pi^+\\pi^-$ with a\nsubsequent $ \\Upsilon(1S) \\to \\mu^+ \\mu^-$ transition. This is the first\nexample of a non-$B \\bar{B}$ decay of the $\\Upsilon(4S)$ resonance. The\npreliminary estimated branching fraction is equal to\n$\\mathcal{B}(\\Upsilon(4S)\\to \\Upsilon(1S)\\pi^+\\pi^-) = (1.1 \\pm\n0.2(\\mathrm{stat.}) \\pm 0.4(\\mathrm{sys.}))\\times 10^{-4}.$", "category": "hep-ex" }, { "text": "Combined search for electroweak production of winos, binos, higgsinos,\n and sleptons in proton-proton collisions at $\\sqrt{s}$ = 13 TeV: A combination of the results of several searches for the electroweak\nproduction of the supersymmetric partners of standard model bosons, and of\ncharged leptons, is presented. All searches use proton-proton collision data at\n$\\sqrt{s}$ = 13 TeV recorded with the CMS detector at the LHC in 2016-2018. The\nanalyzed data correspond to an integrated luminosity of up to 137 fb$^{-1}$.\nThe results are interpreted in terms of simplified models of supersymmetry. Two\nnew interpretations are added with this combination: a model spectrum with the\nbino as the lightest supersymmetric particle together with mass-degenerate\nhiggsinos decaying to the bino and a standard model boson, and the\ncompressed-spectrum region of a previously studied model of slepton pair\nproduction. Improved analysis techniques are employed to optimize sensitivity\nfor the compressed spectra in the wino and slepton pair production models. The\nresults are consistent with expectations from the standard model. The\ncombination provides a more comprehensive coverage of the model parameter space\nthan the individual searches, extending the exclusion by up to 125 GeV, and\nalso targets some of the intermediate gaps in the mass coverage.", "category": "hep-ex" }, { "text": "Measurement of Orbitally Excited D-Mesons at CDF II: Measurement of Orbitally Excited D-Mesons at CDF II Igor V. Gorelov (For the\nCDF Collaboration)\n Talk given on behalf of the CDF Collaboration at the First Meeting of the APS\nTopical Group on Hadronic Physics, GHP 2004, 24-26 October 2004, FERMILAB.\nResults on the first measurement of orbitally excited neutral D-meson states,\nD*_2 and D_1, produced in hadron collisions at Tevatron are presented. Using\ndata from the displaced track trigger, CDF II collects the largest world sample\nof these states in decay modes D*+ pi-, D+ pi-. Masses and widths of both\nstates have been measured with precision better than or comparable to the world\naverage.", "category": "hep-ex" }, { "text": "Particle Correlations in Z and WW Events: Important information about the dynamics of hadron production can be obtained\nby the study of particle correlations. More than 16 million hadronic Z0 decays\nand several thousand W+W- events have been recorded from the four LEP\ncollaborations between 1989 and 2000. Recently, in Z0 decays, new results of\nBose-Einstein correlations in pairs of pions and Fermi-Dirac correlations for\nantiproton pairs were reported. In fully-hadronic W+W- decays particle\ncorrelations were used to study whether the two W bosons decay independently.", "category": "hep-ex" }, { "text": "Measurement of the production of neighbouring jets in lead-lead\n collisions at $\\sqrt{s_{\\mathrm{NN}}} = 2.76$ TeV with the ATLAS detector: This Letter presents measurements of correlated production of nearby jets in\nPb+Pb collisions at $\\sqrt{s_{\\mathrm{NN}}} = 2.76$ TeV using the ATLAS\ndetector at the Large Hadron Collider. The measurement was performed using 0.14\n${\\rm nb}^{-1}$ of data recorded in 2011. The production of correlated jet\npairs was quantified using the rate, $R_{\\Delta R}$, of \"neighbouring\" jets\nthat accompany \"test\" jets within a given range of angular distance, $\\Delta\nR$, in the pseudorapidity--azimuthal angle plane. The jets were measured in the\nATLAS calorimeter and were reconstructed using the anti-$k_{t}$ algorithm with\nradius parameters $d = 0.2$, $0.3$, and $0.4$. $R_{\\Delta R}$ was measured in\ndifferent Pb+Pb collision centrality bins, characterized by the total\ntransverse energy measured in the forward calorimeters. A centrality dependence\nof $R_{\\Delta R}$ is observed for all three jet radii with $R_{\\Delta R}$ found\nto be lower in central collisions than in peripheral collisions. The ratios\nformed by the $R_{\\Delta R}$ values in different centrality bins and the values\nin the 40-80 % centrality bin are presented.", "category": "hep-ex" }, { "text": "Top-quark pair production in association with a $Z$ boson in the 4$\\ell$\n channel with the ATLAS experiment: The cross section of the $t\\bar{t}Z$~and $t\\bar{t}W$~processes are measured\nin a simultaneous fit using 36.1 $\\text{fb}^{-1}$ of of proton--proton\ncollisions at a centre-of-mass energy of $\\sqrt{s}=13$ TeV recorded by the\nATLAS experiment at the LHC. In addition, a fit is performed in the 4$\\ell$\nchannel only, resulting in a cross section of $\\sigma_{t\\bar{t}Z} = 1.07 \\pm\n0.26 \\,\\text{pb}$. This result is consistent with the combined fit and agrees\nwith the prediction by the Standard Model.", "category": "hep-ex" }, { "text": "Fraction Constraint in Partial Wave Analysis: To resolve the non-convex optimization problem in partial wave analysis, this\npaper introduces a novel approach that incorporates fraction constraints into\nthe likelihood function. This method offers significant improvements in both\nthe efficiency of pole searching and the reliability of resonance selection\nwithin partial wave analysis.", "category": "hep-ex" }, { "text": "Indirect CP violation results and HFAG averages: The current status of the search for indirect CP violation in the neutral D\nmeson system at the B-factories and at LHCb is reported. The indirect CP\nasymmetry search is performed by the measurement of the proper-time asymmetry\n($A_{\\Gamma}$) in decays of $D^0-\\bar{D^0}$ mesons to CP eigenstates, $K^-K^+$\nand $\\pi^- \\pi^+$, and by $y_{CP}$, the ratio between the effective lifetime\nmeasured in decay to a CP eigenstate and that to the mixed eigenstate $K \\pi$.\nAll results are consistent with the no CP violation hypothesis. The latest\nworld averages for mixing and CP asymmetry in the charm sector evaluated by the\nHeavy Flavour Averaging Group are presented. The no mixing hypothesis is\nexcluded at more than 12 standard deviations. The search for direct and\nindirect CP violation in the charm sector is consistent with no CP violation at\n2.0% confident level.", "category": "hep-ex" }, { "text": "Machine Learning Solutions for High Energy Physics: Applications to\n Electromagnetic Shower Generation, Flavor Tagging, and the Search for\n di-Higgs Production: This thesis demonstrate the efficacy of designing and developing machine\nlearning (ML) algorithms to selected use cases that encompass many of the\noutstanding challenges in the field of experimental high energy physics.\nAlthough simple implementations of neural networks and boosted decision trees\nhave been used in high energy physics for a long time, the field of ML has\nquickly evolved by devising more complex, fast and stable implementations of\nlearning algorithms. The complexity and power of state-of-the-art deep learning\nfar exceeds those of the learning algorithms implemented in the CERN-developed\n\\texttt{ROOT} library. All aspects of experimental high energy physics have\nbeen and will continue being revolutionized by the software- and hardware-based\ntechnological advances spearheaded by both academic and industrial research in\nother technical disciplines, and the emergent trend of increased\ninterdisciplinarity will soon reframe many scientific domains. This thesis\nexemplifies this spirit of versatility and multidisciplinarity by bridging the\ngap between ML and particle physics, and exploring original lines of work to\nmodernize the reconstruction, particle identification, simulation, and analysis\nworkflows. This contribution documents a collection of novel approaches to\naugment traditional domain-specific methods with modern, automated techniques\nbased on industry-standard, open-source libraries. Specifically, it contributes\nto setting the state-of-the-art for impact parameter-based flavor tagging and\ndi-Higgs searches in the $\\gamma \\gamma b\\bar{b} $ channel with the ATLAS\ndetector at the LHC, it introduces and lays the foundations for the use of\ngenerative adversarial networks for the simulation of particle showers in\ncalorimeters. These results substantiate the notion of ML powering particle\nphysics in the upcoming years and establish baselines for future applications.", "category": "hep-ex" }, { "text": "$C\\!P$ violation in beauty and charm quarks at LHCb: The LHCb experiment has been reporting remarkable $C\\!P$-violation (CPV)\nmeasurements concerning the sectors of $b$ and $c$ quarks. Recently, the new\nmeasurements of time-integrated CPV with $D^0\\to K^+ K^-$ decays led to the\nfirst evidence ($3.8\\sigma$) of CPV in a single charmed decay. The first search\nfor CPV in the $D_{(s)}^+\\to K^+K^+K^-$ decays was executed. The knowledge of\nthe CKM parameter $\\gamma$ was improved by new results; the current combination\nof the LHCb measurements is: $\\left(63.8^{+3.5}_{-3.7}\\right)^\\circ$. The study\nof $B_s^0\\to\\phi\\phi$ decays resulted in the most precise measurement of\ntime-dependent CPV in any penguin-dominated $B$ meson decay. All the results\nare consistent with the Standard-Model predictions.", "category": "hep-ex" }, { "text": "Search for new particles decaying to a jet and an emerging jet: A search is performed for events consistent with the pair production of a new\nheavy particle that acts as a mediator between a dark sector and normal matter,\nand that decays to a light quark and a new fermion called a dark quark. The\nsearch is based on data corresponding to an integrated luminosity of 16.1\nfb$^{-1}$ from proton-proton collisions at $\\sqrt{s} =$ 13 TeV collected by the\nCMS experiment at the LHC in 2016. The dark quark is charged only under a new\nquantum-chromodynamics-like force, and forms an \"emerging jet\" via a parton\nshower, containing long-lived dark hadrons that give rise to displaced vertices\nwhen decaying to standard model hadrons. The data are consistent with the\nexpectation from standard model processes. Limits are set at 95% confidence\nlevel excluding dark pion decay lengths between 5 and 225 mm for dark mediators\nwith masses between 400 and 1250 GeV. Decay lengths smaller than 5 mm and\ngreater than 225 mm are also excluded in the lower part of this mass range. The\ndependence of the limit on the dark pion mass is weak for masses between 1 and\n10 GeV. This analysis is the first dedicated search for the pair production of\na new particle that decays to a jet and an emerging jet.", "category": "hep-ex" }, { "text": "Precise Neutron Lifetime Measurement Using Pulsed Neutron Beams at\n J-PARC: A neutron decays into a proton, an electron, and an anti-neutrino through the\nbeta-decay process. The decay lifetime ($\\sim$880 s) is an important parameter\nin the weak interaction. For example, the neutron lifetime is a parameter used\nto determine the |$V_{\\rm ud}$| parameter of the CKM quark mixing matrix. The\nlifetime is also one of the input parameters for the Big Bang Nucleosynthesis,\nwhich predicts light element synthesis in the early universe. However,\nexperimental measurements of the neutron lifetime today are significantly\ndifferent (8.4 s or 4.0$\\sigma$) depending on the methods. One is a bottle\nmethod measuring surviving neutron in the neutron storage bottle. The other is\na beam method measuring neutron beam flux and neutron decay rate in the\ndetector. There is a discussion that the discrepancy comes from unconsidered\nsystematic error or undetectable decay mode, such as dark decay. A new type of\nbeam experiment is performed at the BL05 MLF J-PARC. This experiment measured\nneutron flux and decay rate simultaneously with a time projection chamber using\na pulsed neutron beam. We will present the world situation of neutron lifetime\nand the latest results at J-PARC.", "category": "hep-ex" }, { "text": "Measurement of the branching fraction for $\u03c8(3770) \\to\n \u03b3\u03c7_{c0}$: By analyzing a data set of 2.92 fb$^{-1}$ of $e^+e^-$ collision data taken at\n$\\sqrt s= 3.773~\\rm GeV$ and 106.41$\\times 10^{6}$ $\\psi(3686)$ decays taken at\n$\\sqrt s= 3.686~\\rm GeV$ with the BESIII detector at the BEPCII collider, we\nmeasure the branching fraction and the partial decay width for\n$\\psi(3770)\\to\\gamma\\chi_{c0}$ to be ${\\mathcal\nB}(\\psi(3770)\\to\\gamma\\chi_{c0})=(6.88\\pm0.28\\pm0.67)\\times 10^{-3}$ and\n$\\Gamma[\\psi(3770)\\to\\gamma\\chi_{c0}]=(187\\pm8\\pm19)~\\rm keV$, respectively.\nThese are the most precise measurements to date.", "category": "hep-ex" }, { "text": "Precision Analysis of the $^{136}$Xe Two-Neutrino $\u03b2\u03b2$ Spectrum\n in KamLAND-Zen and Its Impact on the Quenching of Nuclear Matrix Elements: We present a precision analysis of the $^{136}$Xe two-neutrino $\\beta\\beta$\nelectron spectrum above 0.8 MeV, based on high-statistics data obtained with\nthe KamLAND-Zen experiment. An improved formalism for the two-neutrino\n$\\beta\\beta$ rate allows us to measure the ratio of the leading and subleading\n$2\\nu\\beta\\beta$ nuclear matrix elements (NMEs), $\\xi^{2\\nu}_{31} =\n-0.26^{+0.31}_{-0.25}$. Theoretical predictions from the nuclear shell model\nand the majority of the quasiparticle random-phase approximation (QRPA)\ncalculations are consistent with the experimental limit. However, part of the\n$\\xi^{2\\nu}_{31}$ range allowed by the QRPA is excluded by the present\nmeasurement at the 90% confidence level. Our analysis reveals that predicted\n$\\xi^{2\\nu}_{31}$ values are sensitive to the quenching of NMEs and the\ncompeting contributions from low- and high-energy states in the intermediate\nnucleus. Since these aspects are also at play in neutrinoless $\\beta\\beta$\ndecay, $\\xi^{2\\nu}_{31}$ provides new insights towards reliable neutrinoless\n$\\beta\\beta$ NMEs.", "category": "hep-ex" }, { "text": "Measurement of isolated-photon plus two-jet production in $pp$\n collisions at $\\sqrt{s}=13$ TeV with the ATLAS detector: The dynamics of isolated-photon plus two-jet production in $pp$ collisions at\na centre-of-mass energy of 13 TeV are studied with the ATLAS detector at the\nLHC using a dataset corresponding to an integrated luminosity of 36.1\nfb$^{-1}$. Cross sections are measured as functions of a variety of\nobservables, including angular correlations and invariant masses of the objects\nin the final state, $\\gamma+jet+jet$. Measurements are also performed in\nphase-space regions enriched in each of the two underlying physical mechanisms,\nnamely direct and fragmentation processes. The measurements cover the range of\nphoton (jet) transverse momenta from 150 GeV (100 GeV) to 2 TeV. The tree-level\nplus parton-shower predictions from SHERPA and PYTHIA as well as the\nnext-to-leading-order QCD predictions from SHERPA are compared with the\nmeasurements. The next-to-leading-order QCD predictions describe the data\nadequately in shape and normalisation except for regions of phase space such as\nthose with high values of the invariant mass or rapidity separation of the two\njets, where the predictions overestimate the data.", "category": "hep-ex" }, { "text": "Search for neutral MSSM Higgs bosons decaying into a pair of bottom\n quarks: A search for neutral Higgs bosons decaying into a b-bbar quark pair and\nproduced in association with at least one additional b quark is presented. This\nsignature is sensitive to the Higgs sector of the minimal supersymmetric\nstandard model (MSSM) with large values of the parameter tan(beta). The\nanalysis is based on data from proton-proton collisions at a center-of-mass\nenergy of 8 TeV collected with the CMS detector at the LHC, corresponding to an\nintegrated luminosity of 19.7 inverse femtobarns. The results are combined with\na previous analysis based on 7 TeV data. No signal is observed. Stringent upper\nlimits on the cross section times branching fraction are derived for Higgs\nbosons with masses up to 900 GeV, and the results are interpreted within\ndifferent MSSM benchmark scenarios, m[h,max], m[h,mod+], m[h,mod-], light-stau\nand light-stop. Observed 95% confidence level upper limits on tan(beta),\nranging from 14 to 50, are obtained in the m[h,mod+] benchmark scenario.", "category": "hep-ex" }, { "text": "Measurement of dijet azimuthal decorrelations in $pp$ collisions at\n $\\sqrt{s}=8$ TeV with the ATLAS detector and determination of the strong\n coupling: A measurement of the rapidity and transverse momentum dependence of dijet\nazimuthal decorrelations is presented, using the quantity $R_{\\Delta \\phi}$.\nThe quantity $R_{\\Delta \\phi}$ specifies the fraction of the inclusive dijet\nevents in which the azimuthal opening angle of the two jets with the highest\ntransverse momenta is less than a given value of the parameter $\\Delta\n\\phi_\\mathrm{max}$. The quantity $R_{\\Delta \\phi}$ is measured in\nproton--proton collisions at $\\sqrt{s}=$8 TeV as a function of the dijet\nrapidity interval, the event total scalar transverse momentum, and $\\Delta\n\\phi_\\mathrm{max}$. The measurement uses an event sample corresponding to an\nintegrated luminosity of 20.2 fb$^{-1}$ collected with the ATLAS detector at\nthe CERN Large Hadron Collider. Predictions of a perturbative QCD calculation\nat next-to-leading order in the strong coupling with corrections for\nnon-perturbative effects are compared to the data. The theoretical predictions\ndescribe the data in the whole kinematic region. The data are used to determine\nthe strong coupling $\\alpha_{\\mathrm{S}}$ and to study its running for momentum\ntransfers from 260 GeV to above 1.6 TeV. An analysis that combines data at all\nmomentum transfers results in $\\alpha_{\\mathrm{S}}(m_{Z}) =\n0.1127^{+0.0063}_{-0.0027}$.", "category": "hep-ex" }, { "text": "Search for the process $e^+e^-\\to \u03b7^\\prime(958)$ with the CMD-3\n detector: A search for the process $\\epem\\to \\eta^\\prime(958)$ in the\n$\\pipi\\eta\\to\\pipi\\gamma\\gamma$ final state has been performed with the CMD-3\ndetector at the VEPP-2000 $e^+e^-$ collider. Using an integrated luminosity of\n2.69 pb$^{-1}$ collected at the center-of-mass energy \\Ecm = 957.68 MeV we set\nan upper limit for the product of electronic width and branching fractions\n$\\Gamma_{\\eta^\\prime(958)\\to\\epem}\\cdot\\BR_{\\eta^\\prime(958)\\to\\pipi\\eta}\\cdot\\BR_{\\eta\\to\\gamma\\gamma}<0.00041$\neV at 90\\% C.L.", "category": "hep-ex" }, { "text": "Tau lepton reconstruction at collider experiments using impact\n parameters: We present a novel method for the reconstruction of events containing pairs\nof hadronically decaying tau leptons at collider experiments. This method\nrelies on accurate knowledge of the tau production vertex and precise\nmeasurement of its charged decay products. The method makes no assumptions\nabout the centre-of-mass or invariant mass of the tau pair, and is insensitive\nto momentum loss along the beam direction. We demonstrate the method using e+e-\n-> mu+ mu- tau+ tau- events fully simulated in the ILD detector.", "category": "hep-ex" }, { "text": "An Improved Measurement of Neutrino Oscillation Parameters by the NOvA\n Experiment: We present new $\\nu_\\mu\\rightarrow\\nu_e$, $\\nu_\\mu\\rightarrow\\nu_\\mu$,\n$\\overline{\\nu}_\\mu\\rightarrow\\overline{\\nu}_e$, and\n$\\overline{\\nu}_\\mu\\rightarrow\\overline{\\nu}_\\mu$ oscillation measurements by\nthe NOvA experiment, with a 50% increase in neutrino-mode beam exposure over\nthe previously reported results. The additional data, combined with previously\npublished neutrino and antineutrino data, are all analyzed using improved\ntechniques and simulations. A joint fit to the $\\nu_e$, $\\nu_\\mu$,\n$\\overline{\\nu}_e$, and $\\overline{\\nu}_\\mu$ candidate samples within the\n3-flavor neutrino oscillation framework continues to yield a best-fit point in\nthe normal mass ordering and the upper octant of the $\\theta_{23}$ mixing\nangle, with $\\Delta m^{2}_{32} = (2.41\\pm0.07)\\times 10^{-3}$ eV$^2$ and\n$\\sin^2\\theta_{23} = 0.57^{+0.03}_{-0.04}$. The data disfavor combinations of\noscillation parameters that give rise to a large asymmetry in the rates of\n$\\nu_e$ and $\\overline{\\nu}_e$ appearance. This includes values of the\nCP-violating phase in the vicinity of $\\delta_\\text{CP} = \\pi/2$ which are\nexcluded by $>3\\sigma$ for the inverted mass ordering, and values around\n$\\delta_\\text{CP} = 3\\pi/2$ in the normal ordering which are disfavored at\n2$\\sigma$ confidence.", "category": "hep-ex" }, { "text": "Search for dark matter in events with missing transverse momentum and a\n Higgs boson decaying into two photons in $pp$ collisions at $\\sqrt{s} = 13$\n TeV with the ATLAS detector: A search for dark-matter particles in events with large missing transverse\nmomentum and a Higgs boson candidate decaying into two photons is reported. The\nsearch uses $139$ fb$^{-1}$ of proton-proton collision data collected at\n$\\sqrt{s}=13$ TeV with the ATLAS detector at the CERN LHC between 2015 and\n2018. No significant excess of events over the Standard Model predictions is\nobserved. The results are interpreted by extracting limits on three simplified\nmodels that include either vector or pseudoscalar mediators and predict a final\nstate with a pair of dark-matter candidates and a Higgs boson decaying into two\nphotons.", "category": "hep-ex" }, { "text": "Differential cross section measurements for the production of a W boson\n in association with jets in proton-proton collisions at sqrt(s) = 7 TeV: Measurements are reported of differential cross sections for the production\nof a W boson, which decays into a muon and a neutrino, in association with\njets, as a function of several variables, including the transverse momenta (pt)\nand pseudorapidities of the four leading jets, the scalar sum of jet transverse\nmomenta (HT), and the difference in azimuthal angle between the directions of\neach jet and the muon. The data sample of pp collisions at a centre-of-mass\nenergy of 7 TeV was collected with the CMS detector at the LHC and corresponds\nto an integrated luminosity of 5.0 inverse femtobarns. The measured cross\nsections are compared to predictions from Monte Carlo generators, MADGRAPH +\nPYTHIA and SHERPA, and to next-to-leading-order calculations from BLACKHAT +\nSHERPA. The differential cross sections are found to be in agreement with the\npredictions, apart from the pt distributions of the leading jets at high pt\nvalues, the distributions of the HT at high-HT and low jet multiplicity, and\nthe distribution of the difference in azimuthal angle between the leading jet\nand the muon at low values.", "category": "hep-ex" }, { "text": "New measurement of $\u03b8_{13}$ via neutron capture on hydrogen at Daya\n Bay: This article reports an improved independent measurement of neutrino mixing\nangle $\\theta_{13}$ at the Daya Bay Reactor Neutrino Experiment. Electron\nantineutrinos were identified by inverse $\\beta$-decays with the emitted\nneutron captured by hydrogen, yielding a data-set with principally distinct\nuncertainties from that with neutrons captured by gadolinium. With the final\ntwo of eight antineutrino detectors installed, this study used 621 days of data\nincluding the previously reported 217-day data set with six detectors. The\ndominant statistical uncertainty was reduced by 49%. Intensive studies of the\ncosmogenic muon-induced $^9$Li and fast neutron backgrounds and the\nneutron-capture energy selection efficiency, resulted in a reduction of the\nsystematic uncertainty by 26%. The deficit in the detected number of\nantineutrinos at the far detectors relative to the expected number based on the\nnear detectors yielded $\\sin^22\\theta_{13} = 0.071 \\pm 0.011$ in the\nthree-neutrino-oscillation framework. The combination of this result with the\ngadolinium-capture result is also reported.", "category": "hep-ex" }, { "text": "Observation of the semi-muonic decay $D^+\\to \u03c9\u03bc^+\u03bd_\u03bc$: We report the first observation of the semi-muonic decay $D^+\\to \\omega\n\\mu^+\\nu_\\mu$ using an $e^+e^-$ collision data sample corresponding to an\nintegrated luminosity of $2.93~\\mathrm{fb}^{-1}$ collected with the BESIII\ndetector at a center-of-mass energy of 3.773 GeV. The absolute branching\nfraction of the $D^+\\to \\omega \\mu^+\\nu_\\mu$ decay is measured to be ${\\mathcal\nB}_{D^+\\to \\omega\\mu^+\\nu_\\mu}=(17.7\\pm1.8_{\\rm stat}\\pm1.1_{\\rm syst})\\times\n10^{-4}$. Its ratio with the world average value of the branching fraction of\nthe $D^+\\to \\omega e^+\\nu_e$ decay probes lepton flavor universality and it is\ndetermined to be ${\\mathcal B}_{D^+\\to \\omega \\mu^+\\nu_\\mu}/{\\mathcal B}^{\\rm\nPDG}_{D^+\\to \\omega e^+\\nu_e}=1.05\\pm0.14$, in agreement with the standard\nmodel expectation within one standard deviation.", "category": "hep-ex" }, { "text": "Exploring coherent elastic neutrino-nucleus scattering using reactor\n electron antineutrinos in the NEON experiment: Neutrino elastic scattering observation with NaI (NEON) is an experiment\ndesigned to detect neutrino-nucleus coherent scattering using reactor electron\nantineutrinos. NEON is based on an array of six NaI(Tl) crystals with a total\nmass of 13.3 kg, located at the tendon gallery that is 23.7 m away from a\nreactor core with a thermal power of 2.8 GW in the Hanbit nuclear power\ncomplex. The installation of the NEON detector was completed in December 2020,\nand since May 2021, the detector has acquired data at full reactor power. Based\non the observed light yields of the NaI crystals of approximately 22, number of\nphotoelectrons per unit keV electron-equivalent energy (keVee), and 6\ncounts/kg/keV/day background level at 2-6 keVee energy, coherent elastic\nneutrino-nucleus scattering observation sensitivity is evaluated as more than\n3$\\sigma$ assuming one-year reactor-on and 100 days reactor-off data, 0.2 keVee\nenergy threshold, and 7 counts/keV/kg/day background in the signal region of\n0.2-0.5 keVee. This paper describes the design of the NEON detector, including\nthe shielding arrangement, configuration of NaI(Tl) crystals, and associated\noperating systems. The initial performance and associated sensitivity of the\nexperiment are also presented.", "category": "hep-ex" }, { "text": "Extracting TMDs from CLAS12 data: We present studies of double longitudinal spin asymmetries in semi-inclusive\ndeep inelastic scattering using a new dedicated Monte Carlo generator, which\nincludes quark intrinsic transverse momentum within the generalized parton\nmodel based on the fully differential cross section for the process.\nAdditionally we employ Bessel-weighting to the MC events to extract transverse\nmomentum dependent parton distribution functions and also discuss possible\nuncertainties due to kinematic correlation effects.", "category": "hep-ex" }, { "text": "Study of the $\u03c1$ and $\u03c9$ meson decays into pseudoscalar meson\n and $e^+e^-$ pair with the CMD-2 detector: Using 3.3 pb$^{-1}$ of data collected with the CMD-2 detector in the 720 --\n840 MeV c.m. energy range, the branching fraction of the conversion decay\n$\\omega\\to\\pi^0e^+e^-$ has been measured:\n$\\mathcal{B}(\\omega\\to\\pi^0e^+e^-)=(8.19\\pm0.71\\pm0.62)\\cdot10^{-4}$. The upper\nlimits for the branching fractions of the following conversion decays have been\nobtained at the 90% confidence level:\n$\\mathcal{B}(\\rho\\to\\pi^0e^+e^-)<1.6\\cdot10^{-5}$, $\\mathcal{B}(\\rho\\to\\eta\ne^+e^-)<0.7\\cdot10^{-5}$ and $\\mathcal{B}(\\omega\\to\\eta\ne^+e^-)<1.1\\cdot10^{-5}$.", "category": "hep-ex" }, { "text": "Snowmass Neutrino Frontier: Neutrino Interaction Cross Sections (NF06)\n Topical Group Report: A thorough understanding of neutrino cross sections in a wide range of\nenergies is crucial for the successful execution of the entire neutrino physics\nprogram. In order to extract neutrino properties, long-baseline experiments\nneed an accurate determination of neutrino cross sections within their\ndetector(s). Since very few of the needed neutrino cross sections across the\nenergy spectrum are directly measured, we emphasize the need for theoretical\ninput and indirect measurements such as electron scattering, which would\ncomplement direct measurements. In this report we briefly summarize the current\nstatus of our knowledge of the neutrino cross sections and articulate needs of\nthe experiments, ongoing and planned, at energies ranging from CEvNS and\nsupernova neutrino energies to the DUNE and atmospheric neutrino energies.", "category": "hep-ex" }, { "text": "A new parameterization of the nucleon elastic form factors: The nucleon elastic form factors are generally interpreted as a mapping of\nthe charge and magnetic current distributions of the proton and neutron. New\nhigh Q^2 measurements have opened up fundamental questions about G_ep that\nremain to be answered. This talk will summarize current developments\nsurrounding the nucleon form factors and explain why they are important to\nneutrino physicists. New parameterizations of the nucleon form factors,\nsuitable for use by neutrino physicists, will be introduced and discussed.", "category": "hep-ex" }, { "text": "Search for decays of stopped long-lived particles produced in\n proton-proton collisions at sqrt(s) = 8 TeV: A search has been performed for long-lived particles that could have come to\nrest within the CMS detector, using the time intervals between LHC beam\ncrossings. The existence of such particles could be deduced from observation of\ntheir decays via energy deposits in the CMS calorimeter appearing at times that\nare well separated from any proton-proton collisions. Using a data set\ncorresponding to an integrated luminosity of 18.6 inverse femtobarns of 8 TeV\nproton-proton collisions, and a search interval corresponding to 281 hours of\ntrigger livetime, 10 events are observed, with a background prediction of 13.2\n+3.6 -2.5 events. Limits are presented at 95% confidence level on gluino and\ntop squark production, for over 13 orders of magnitude in the mean proper\nlifetime of the stopped particle. Assuming a cloud model of R-hadron\ninteractions, a gluino with mass < 1000 GeV and a top squark with mass < 525\nGeV are excluded, for lifetimes between 1 microsecond and 1000 s. These results\nare the most stringent constraints on stopped particles to date.", "category": "hep-ex" }, { "text": "Universality of the underlying event in pp collisions: In this paper we study ATLAS results on underlying event in pp collisions at\n$\\sqrt{s}$=0.9, 7 and 13 TeV. We show that the center-of-mass energy\ndependences of the charged-particle production sensitive to the underlying\nevent (\"transverse\" region) and to the hardest partonic interaction (\"towards\"\nand \"away\" regions) in pp collisions can be both understood in terms of the\nchange of the inclusive average multiplicity. Within uncertainties, the\ncorresponding particle production as a function of the leading charged particle\nshows no significant $\\sqrt{s}$-dependence for the three regions once they are\nscaled according to the relative change in multiplicity. The scaling properties\nreported here are well reproduced by PYTHIA 8.212 tune Monash 2013 and suggest\nan universality of the underlying event in hadronic interactions at high\n$\\sqrt{s}$. Based on the simulations, we observed that the same scaling\nproperties are also present in the average number of multi-partonic\ninteractions as a function of the leading charged particle. Moreover, the\nmultiplicity distributions associated to the underlying event exhibit a KNO\nscaling.", "category": "hep-ex" }, { "text": "Measurements of the branching fractions of $\u039b_c^+ \\to p \u03b7$ and\n $\u039b_c^+ \\to p \u03c0^0$ decays at Belle: We report measurements of the branching fractions of singly\nCabibbo-suppressed decays $\\Lambda_c^+ \\to p \\eta$ and $\\Lambda_c^+ \\to p\n\\pi^0$ using the full Belle data sample corresponding to an integrated\nluminosity of 980.6 $\\rm fb^{-1}$. The data were collected by the Belle\ndetector at the KEKB $e^{+}$$e^{-}$ asymmetric-energy collider. A clear\n$\\Lambda_c^+$ signal is seen in the invariant mass distribution of $p \\eta$.\nThe signal yield of the $\\Lambda_c^+ \\to p \\eta$ process is $7734 \\pm 263$;\nfrom this, we measure the ratio of branching fractions ${\\cal B}(\\Lambda_c^+\n\\to p \\eta)/{\\cal B}(\\Lambda_c^+ \\to p K^- \\pi^+) = (2.258 \\pm 0. 077(\\rm stat.\n) \\pm 0.136(\\rm syst. ))\\times 10^{-2}$, from which we infer the branching\nfraction ${\\cal B}(\\Lambda_c^+ \\to p \\eta) = (1.42 \\pm 0.05(\\rm stat.) \\pm\n0.11(\\rm syst.)) \\times 10^{-3}$. In addition, no significant signal for\n$\\Lambda_c^+ \\to p \\pi^0$ is found so an upper limit on the branching fraction\nof ${\\cal B}(\\Lambda_c^+ \\to p \\pi^0)<8.0 \\times 10^{-5}$ at 90\\% credibility\nlevel is set, more than three times better than the best current upper limit.", "category": "hep-ex" }, { "text": "Long-term temporal stability of the DarkSide-50 dark matter detector: The stability of a dark matter detector on the timescale of a few years is a\nkey requirement due to the large exposure needed to achieve a competitive\nsensitivity. It is especially crucial to enable the detector to potentially\ndetect any annual event rate modulation, an expected dark matter signature. In\nthis work, we present the performance history of the DarkSide-50 dual-phase\nargon time projection chamber over its almost three-year low-radioactivity\nargon run. In particular, we focus on the electroluminescence signal that\nenables sensitivity to sub-keV energy depositions. The stability of the\nelectroluminescence yield is found to be better than 0.5%. Finally, we show the\ntemporal evolution of the observed event rate around the sub-keV region being\nconsistent to the background prediction.", "category": "hep-ex" }, { "text": "Measurement of neutral-current $K^+$ production by neutrinos using\n MINERvA: Neutral-current production of $K^{+}$ by atmospheric neutrinos is a\nbackground in searches for the proton decay $p \\rightarrow K^{+} \\bar{\\nu}$.\nReactions such as $\\nu p \\rightarrow \\nu K^{+} \\Lambda$ are indistinguishable\nfrom proton decays when the decay products of the $\\Lambda$ are below detection\nthreshold. Events with $K^{+}$ are identified in MINERvA by reconstructing the\ntiming signature of a $K^{+}$ decay at rest. A sample of 201 neutrino-induced\nneutral-current $K^{+}$ events is used to measure differential cross sections\nwith respect to the $K^{+}$ kinetic energy, and the non-$K^{+}$ hadronic\nvisible energy. An excess of events at low hadronic visible energy is observed\nrelative to the prediction of the NEUT event generator. Good agreement is\nobserved with the cross section prediction of the GENIE generator. A search for\nphotons from $\\pi^{0}$ decay, which would veto a neutral-current $K^{+}$ event\nin a proton decay search, is performed, and a 2$\\sigma$ deficit of detached\nphotons is observed relative to the GENIE prediction.", "category": "hep-ex" }, { "text": "Status of Dual-Readout Calorimetry for Future High-Energy Physics\n Experiments: Future experiments at high energy $e^+e^-$ colliders will focus on extremely\nprecise Standard Model measurements. Among the most important physics\nbenchmarks, there is the capability to resolve the Higgs decays into W or Z\npairs, in their completely hadronic decay modes (4 jets in the final state),\nonly based on the invariant mass of the jet pair coming from decay of the\non-shell boson. This translates into a relative energy resolution target of\n$30\\%/\\sqrt{E}$, well beyond current detector performances. Dual-readout\ncalorimetry is a technique which aims to improve the energy resolution, for\nsingle hadrons and hadronic jets, exploiting the information produced by two\ndifferent physical processes, namely scintillation and Cerenkov light emission.\nThe IDEA detector, whose concept has been included in both the FCC and CEPC\nConceptual Design Reports, is based on a dual-readout fibre calorimeter with\nindependent fibre readout exploiting Silicon PhotoMultipliers (SiPMs). The\nindividual SiPM information will be beneficial for a highly granular\ncalorimeter design, opening up to advanced reconstruction techniques such as\nParticle Flow and a variety of neural network algorithms. In this paper the\nstatus of calorimeter prototypes that have been developed to demonstrate the\nfeasibility of the dual-readout method in association with the high granularity\nfeature is illustrated. The specific choice for the design of each prototype is\npresented, together with the performances achieved at high-energy test beams or\nthrough simulations.", "category": "hep-ex" }, { "text": "LHC experiments for long-lived particles of the dark sector: Dark matter scenarios are being tested at the LHC in the general-purpose\nexperiments through promptly decaying states. In parallel, new dedicated\ndetectors have been proposed for the LHC to probe dark matter portal theories\npredicting long-lived particles that decay away from the interaction point:\nMoEDAL-MAPP, MoEDAL-MALL, FASER, SND@LHC, CODEX-b, MATHUSLA, AL3X, ANUBIS,\nFACET, milliQan, FORMOSA. In addition, the SHiP beam-dump experiment is planned\nto operate with the SPS beam to extend the discovery reach for such particles.\nThe detector design and expected physics sensitivity of these experiments is\npresented with emphasis on scenarios explaining the nature of dark matter.", "category": "hep-ex" }, { "text": "Top physics in ATLAS: These proceedings summarize the latest measurements on top production, top\nproperties and searches using the ATLAS detector at the LHC. The measurements\nare performed on $pp$ collision data with a center of mass energy $\\sqrt{s} =\n7, 8$ and $13$ TeV.", "category": "hep-ex" }, { "text": "Measurement of $\u03bd_\u03bc$ and $\\bar\u03bd_\u03bc$ Neutral Current\n $\u03c0^{0} \\rightarrow \u03b3\u03b3$ Production in the ArgoNeuT Detector: The ArgoNeuT collaboration reports the first measurement of neutral current\n$\\pi^{0}$ production in $\\nu_{\\mu}$-argon and $\\bar{\\nu}_{\\mu}$-argon\nscattering. This measurement was performed using the ArgoNeuT liquid argon time\nprojection chamber deployed at Fermilab's NuMI neutrino beam with an exposure\ncorresponding to 1.2$\\times 10^{20}$ protons-on-target from the Fermilab Main\nInjector and a mean energy for $\\nu_{\\mu}$ of 9.6~GeV and for $\\bar{\\nu}_{\\mu}$\nof 3.6~GeV. We compare the measured cross section and kinematic distributions\nto predictions from the GENIE and NuWro neutrino interaction event generators.", "category": "hep-ex" }, { "text": "Search for stop production in R-parity-violating supersymmetry at HERA: A search for stop production in R-parity-violating supersymmetry has been\nperformed in $e^{+}p$ interactions with the ZEUS detector at HERA, using an\nintegrated luminosity of 65 pb$^{-1}$. At HERA, the R-parity-violating coupling\n$\\lambda'$ allows resonant squark production, $e^+d\\to\\tilde{q}$. Since the\nlowest-mass squark state in most supersymmetry models is the light stop,\n$\\tilde{t}$, this search concentrated on production of $\\tilde{t}$, followed\neither by a direct R-parity-violating decay, or by the gauge decay to\n$b\\tilde{\\chi}^+_{1}$. No evidence for stop production was found and limits\nwere set on $\\lambda'_{131}$ as a function of the stop mass in the framework of\nthe Minimal Supersymmetric Standard Model. The results have also been\ninterpreted in terms of constraints on the parameters of the minimal\nSupergravity model.", "category": "hep-ex" }, { "text": "Heavy Flavour results from Tevatron: The CDF and D0 experiments finalize the analysis of their full statistics\ncollected in the $p \\bar p$ collisions at a center-of-mass energy of $\\sqrt{s}\n= 1.96$ TeV at the Fermilab Tevatron collider. This paper presents several new\nresults on the properties of hadrons containing heavy $b$- and $c$-quarks\nobtained by both collaborations. These results include the search for the rare\ndecays $B^0, B^0_s \\to \\mu^+ \\mu^-$ (CDF), the study of CP asymmetry in $B_s\n\\to J\\psi \\phi$ decay (CDF, D0), the measurement of the like-sign dimuon charge\nasymmetry (D0), the measurement of CP asymmetry in $D^0 \\to K^+K^-$ and $D^0\n\\to \\pi^+\\pi^-$ decays (CDF), and the new measurement of the $B_s \\to\nD_s^{(*)+} D_s^{(*)-}$ branching fraction (CDF). Both experiments still expect\nto produce more results on the properties of heavy flavours.", "category": "hep-ex" }, { "text": "Measurement of F_2^{c\\bar{c}} and F_2^{b\\bar{b}} at Low Q^2 and x using\n the H1 Vertex Detector at HERA: Measurements are presented of inclusive charm and beauty cross sections in\ne^+p collisions at HERA for values of photon virtuality 12 \\le Q^2 \\le 60 GeV^2\nand of the Bjorken scaling variable 0.0002 \\le x \\le 0.005. The fractions of\nevents containing charm and beauty quarks are determined using a method based\non the impact parameter, in the transverse plane, of tracks to the primary\nvertex, as measured by the H1 vertex detector. Values for the structure\nfunctions F_2^{c\\bar{c}} and F_2^{b\\bar{b}} are obtained. This is the first\nmeasurement of F_2^{b\\bar{b}} in this kinematic range. The results are found to\nbe compatible with the predictions of perturbative quantum chromodynamics and\nwithprevious measurements of F_2^{c\\bar{c}}.", "category": "hep-ex" }, { "text": "Observation of the decay $\u03c8(3686)$ $\\rightarrow$\n $\u039b\\bar\u03a3^{\\pm}\u03c0^{\\mp}+c.c.$: Using a sample of $1.06\\times10^{8}$ $\\psi(3686)$ events collected with the\nBESIII detector, we present the first observation of the decays of $\\psi(3686)$\n$\\rightarrow$ $\\Lambda\\bar\\Sigma^{+}\\pi^{-}+c.c.$ and $\\psi(3686)$\n$\\rightarrow$ $\\Lambda\\bar\\Sigma^{-}\\pi^{+}+c.c.$. The branching fractions are\nmeasured to be $\\mathcal{B}(\\psi(3686) \\rightarrow \\Lambda\\bar\\Sigma^{+}\\pi^{-}\n+ c.c.)=(1.40\\pm 0.03 \\pm 0.13)\\times10^{-4}$ and $\\mathcal{B}(\\psi(3686)\n\\rightarrow \\Lambda\\bar\\Sigma^{-}\\pi^{+}+c.c.)=(1.54\\pm 0.04 \\pm\n0.13)\\times10^{-4}$, where the first errors are statistical and the second ones\nsystematic.", "category": "hep-ex" }, { "text": "Observation of the Decay \\bar{B0}-> Ds+ Lambda \\bar{p}: We report the first observation of the decay \\bar{B0} -> D_s^+ Lambda \\bar{p}\nwith a statistical significance of 6.6 sigma. We measure Br(\\bar{B0} -> Ds+\nLambda \\bar{p}) = (2.9 \\pm 0.7\\pm 0.5 \\pm 0.4)* 10^{-5}, where the first error\nis statistical, the second is systematic and the third error comes fr\\om the\nuncertainty in Br(Ds+ -> phi pi+). The data used for this analysis was\naccumulated at the Upsilon(4S) resonance, using the Belle detector at the KEKB\nasymmetric-energy e+e- collider. The integrated luminosity of the data sample\nis 414 fb-1, corresponding to 449*10^{6} B{\\bar B} pairs.", "category": "hep-ex" }, { "text": "Measurement of the branching fraction and search for CP violation in\n $D^0\\rightarrow K^0_S\\,K^0_S\\,\u03c0^+\u03c0^-$ decays at Belle: We measure the branching fraction for the Cabibbo-suppressed decay\n$D^0\\rightarrow K^0_S\\,K^0_S\\,\\pi^+\\pi^-$ and search for $CP$ violation via a\nmeasurement of the $CP$ asymmetry $A_{\\rm CP}$ as well as the $T$-odd\ntriple-product asymmetry $a^T_{\\rm CP}$. We use 922 fb$^{-1}$ of data recorded\nby the Belle experiment, which ran at the KEKB asymmetric-energy $e^+e^-$\ncollider. The branching fraction is measured relative to the Cabibbo-favored\nnormalization channel $D^0\\rightarrow K^0_S\\,\\pi^+\\pi^-$; the result is\n$\\mathcal{B}(D^0\\rightarrow K^0_S\\,K^0_S\\,\\pi^+\\pi^-) = [4.79 \\pm 0.08\\,({\\rm\nstat}) \\pm 0.10\\,({\\rm syst}) \\pm 0.31\\,({\\rm norm})]\\times 10^{-4}$, where the\nfirst uncertainty is statistical, the second is systematic, and the third is\nfrom uncertainty in the normalization channel. We also measure $A_{\\rm CP} =\n[-2.51\\,\\pm 1.44\\,({\\rm stat})\\,^{+0.11}_{-0.10}\\,({\\rm syst})]\\%$, and\n$a^T_{\\rm CP} = [-1.95\\,\\pm 1.42\\,({\\rm stat})\\,^{+0.14}_{-0.12}\\,({\\rm\nsyst})]\\%$. These results show no evidence of CP violation.", "category": "hep-ex" }, { "text": "Search for charged Higgs bosons in decays of top quarks: We present a search for charged Higgs bosons in decays of top quarks, in the\nmass range $80 < m_{H^{\\pm} < 155$ GeV, assuming the subsequent decay $H^{+}\n\\to \\tau^{+} \\nu_\\tau$ (and its charge conjugate). Using 0.9 fb$^{-1}$ of\nlepton+jets data collected with the D0 detector at the Fermilab Tevatron\n$p\\bar{p}$ collider, operating at a center of mass energy $\\sqrt{s}=1.96$ TeV,\nwe find no evidence for a $H^{\\pm}$ signal. Hence, we exclude branching ratios\n$B(t \\to H^+b) > 0.24$ for $m_{H^{\\pm}=80$ GeV, and $B(t \\to H^+b) > 0.19$ for\n$m_{H^{\\pm}=155$ GeV, at the 95% C.L.", "category": "hep-ex" }, { "text": "Recent Results from KTeV: The implications of the published KTeV $K^0_L \\to \\pi^0\\mu^+\\mu^-$ result for\ninterpreting recent $\\Sigma^+ \\to p\\mu^+\\mu^-$ results are discussed. The\nstatus of the KTeV $\\Xi^0 \\to \\Sigma^+\\mu^-\\nu$ analysis is given. The KTeV\n$|V_{us}|$ result is also given.", "category": "hep-ex" }, { "text": "Measurement of the top pair production cross-section in 8 TeV\n proton-proton collisions using kinematic information in the lepton+jets final\n state with ATLAS: A measurement is presented of the $t\\bar{t}$ inclusive production\ncross-section in $pp$ collisions at a center-of-mass energy of $\\sqrt{s}=8$ TeV\nusing data collected by the ATLAS detector at the CERN Large Hadron Collider.\nThe measurement was performed in the lepton+jets final state using a data set\ncorresponding to an integrated luminosity of 20.3 fb$^{-1}$. The cross-section\nwas obtained using a likelihood discriminant fit and $b$-jet identification was\nused to improve the signal-to-background ratio. The inclusive $t\\bar{t}$\nproduction cross-section was measured to be $260\\pm 1{\\textrm{(stat.)}}\n^{+22}_{-23} {\\textrm{(syst.)}}\\pm 8{\\textrm{(lumi.)}}\\pm 4{\\mathrm{(beam)}}$\npb assuming a top-quark mass of 172.5 GeV, in good agreement with the\ntheoretical prediction of $253^{+13}_{-15}$ pb. The $t\\bar{t}\\to\n(e,\\mu)+{\\mathrm{jets}}$ production cross-section in the fiducial region\ndetermined by the detector acceptance is also reported.", "category": "hep-ex" }, { "text": "Early Search for Supersymmetry at ATLAS: The search for physics beyond the Standard Model (BSM) is one of the most\nimportant goals for the general purpose detector ATLAS at the Large Hadron\nCollider at CERN. Supersymmetry search strategies based on generic event\nsignatures of high jet multiplicity and large missing transverse momentum,\noptionally including leptons in the final state with R-parity conservation are\ndiscussed in this document. We review the results for above SUSY search\nstrategies with first data up to 305 $nb^{-1}$ of integrated luminosity\ncollected by ATLAS during 2010 at a centre-of-mass energy of 7 TeV.", "category": "hep-ex" }, { "text": "Prospects for Measuring B_s->mu mu with the CMS Detector: The flavor-changing neutral current decay B_s->mu mu is highly suppressed in\nthe standard model, but its branching fraction of 3.4*10^-9 could be\nsignificantly enhanced through contributions from new physics. At the LHC, this\nrare decay could be observed for the first time. In this contribution, the\nprospects for measuring B_s->mu mu with the CMS detector are presented. In\nparticular, some aspects of the experimental setup, the first and high level\ntrigger selections, and the offline analysis are discussed.", "category": "hep-ex" }, { "text": "Double Chooz: results towards the near detector phase: Since the first indication in 2011 of a non-vanishing value of $\\theta_{13}$\nusing reactor neutrinos by Double Chooz, this collaboration has developed new\nanalyses leading to an increased precision on $\\theta_{13}$ and different\ncross-checks of the oscillation results. Beyond the update of the analysis\nbased on neutron captures on Gd in 2012, Double Chooz has also released a\nconsistent measurement of $\\theta_{13}$ by means of neutron captures on H. The\ncombination of the n-Gd and n-H data samples, as well as 7.23 days of reactor\noff data, in a global rate+shape analysis yields $\\sin^22\\theta_{13} = 0.109\\pm\n0.035$. This measurement has been validated with a new\nbackground-model-independent approach, which compares the observed and expected\nneutrino rates as a function of reactor power. This Reactor Rate Modulation\nanalysis yields $\\sin^22\\theta_{13} = 0.102\\pm 0.043$ when combining the n-Gd\nand n-H samples. The Double Chooz collaboration is currently developing a new\nanalysis increasing the signal-to-background ratio while reducing the\nbackground and detection systematics. This new approach is being prepared as a\nfirst step of the new phase of the experiment that will begin in summer 2014\nwith the operation of a near detector.", "category": "hep-ex" }, { "text": "Measurements of $t\\bar{t}$ spin correlations in CMS: We present an overview of the measurements of $t\\bar{t}$ spin correlations in\nthe CMS Collaboration. We present two analyses both in the dilepton channel\nusing proton-proton collisions at $\\sqrt{s}\\, =\\, 7$ TeV based on an integrated\nluminosity of 5.0 fb$^{-1}$. The spin correlations and polarization are\nmeasured using angular asymmetries. The results are consistent with unpolarized\ntop quarks and Standard Model spin correlation. The second analysis sets a\nlimit on the real part of the top-quark chromo-magnetic dipole moment of\n$-0.043\\, <\\, Re({\\hat{\\mu}}_{t})\\, <\\, 0.117$ at $95\\,%$ confidence level\nthrough the measured azimuthal angle difference between the two charged leptons\nfrom $t\\bar{t}$ production.", "category": "hep-ex" }, { "text": "Strangeness Production in Deep-Inelastic Positron-Proton Scattering at\n HERA: Measurements are presented of $K^0$ meson and $\\Lambda$ baryon production in\ndeep-inelastic positron-proton scattering (DIS) in the kinematic range $10 <\nQ^2 < 70 $GeV$^2$ and $10^{-4} < x < 10^{-2}$. The measurements, obtained using\nthe H1 detector at the HERA collider, are discussed in the light of possible\nmechanisms for increased strangeness production at low Bjorken-$x$. Comparisons\nof the $x_F$ spectra, where $x_F$ is the fractional longitudinal momentum in\nthe hadronic centre-of-mass frame, with results from electron-positron\nannihilation are made. The $x_F$ spectra and the $K^0$ ``seagull'' plot are\ncompared with previous DIS results. The mean $K^0$ and $\\Lambda$ multiplicities\nare studied as a function of the centre-of-mass energy $W$ and are observed to\nbe consistent with a logarithmic increase with $W$ when compared with previous\nmeasurements. A comparison of the levels of strangeness production in\ndiffractive and non-diffractive DIS is made. An upper limit of $0.9 $nb, at the\n95% confidence level, is placed on the cross-section for QCD instanton induced\nevents.", "category": "hep-ex" }, { "text": "Spin Physics Progress with the STAR Detector at RHIC: Progress in STAR over the last two years and projections for the coming two\nyears are discussed. Important technical developments have been the completion\nof the barrel and endcap electromagnetic calorimeters. Measurement of inclusive\npi_0 and jet A_LL over the next two years are expected to answer whether\n$\\Delta$G is a major contributor to the proton's spin. Transverse effects such\nas Collins and Sivers functions at mid-rapidity will also be investigated.", "category": "hep-ex" }, { "text": "Muon identification using multivariate techniques in the CMS experiment\n in proton-proton collisions at $\\sqrt{s}$ = 13 TeV: The identification of prompt and isolated muons, as well as muons from\nheavy-flavour hadron decays, is an important task. We developed two\nmultivariate techniques to provide highly efficient identification for muons\nwith transverse momentum greater than 10 GeV. One provides a continuous\nvariable as an alternative to a cut-based identification selection and offers a\nbetter discrimination power against misidentified muons. The other one selects\nprompt and isolated muons by using isolation requirements to reduce the\ncontamination from nonprompt muons arising in heavy-flavour hadron decays. Both\nalgorithms are developed using 59.7 fb$^{-1}$ of proton-proton collisions data\nat a centre-of-mass energy of $\\sqrt{s}$ = 13 TeV collected in 2018 with the\nCMS experiment at the CERN LHC.", "category": "hep-ex" }, { "text": "Search for transitions from $\u03a5(4S)$ and $\u03a5(5S)$ to\n $\u03b7_b(1S)$ and $\u03b7_b(2S)$ with emission of an $\u03c9$ meson: Using data collected in the Belle experiment at the KEKB asymmetric-energy\n$e^+e^-$ collider we search for transitions $\\Upsilon(4S) \\rightarrow\n\\eta_b(1S)\\omega$, $\\Upsilon(5S) \\rightarrow \\eta_b(1S)\\omega$ and\n$\\Upsilon(5S) \\rightarrow \\eta_b(2S)\\omega$. No significant signals are\nobserved and we set 90\\% confidence level upper limits on the corresponding\nvisible cross sections: $0.2 ~\\textrm{pb}, 0.4 ~\\textrm{pb}$ and $1.9\n~\\textrm{pb}$, respectively.", "category": "hep-ex" }, { "text": "T Violation and CPT Tests in Neutral-Meson Systems: The review covers transitions between M0 and M0bar in all four systems M0 =\nK0, D0, B0 and Bs. These systems are ideal laboratories for studying the\ndiscrete symmetries T and CPT. The properties of time reversal T are discussed\nin classical and quantum mechanics. T violation in K0 K0bar transitions has\nbeen observed in 1970 independent of assuming CPT symmetry by using the\nBell-steinberger unitarity relation. Improvements of this observation are\nreviewed including the latest results in 2013. They show with high significance\nthat CP violation in K0 K0bar transitions is only T violation without any CPT\nviolation. Transitions in the other three systems do not show CP violation so\nfar and therefore neither T nor CPT violation. The large observed CP violation\nin B0 -> J/psi K0 decays is presented to be compatible with only T and no CPT\nviolation, the same for the very small but significant CP violation in decays\nK0 -> pi pi with isospin 2.", "category": "hep-ex" }, { "text": "Heavy quark production at HERA and the LHC: Measurements of heavy quark production, particularly from HERA, their\ntheoretical understanding and their relevance for the LHC are reviewed. The\nstatus of beauty and charm production is discussed in the context of the\ndifferent components of the production process: the parton density function of\nthe colliding hadrons; the hard scatter; and the fragmentation of the quarks\ninto hadrons. The theory of QCD at next-to-leading order generally describes\nwell the hadronic structure and the production of heavy quarks although\nsometimes fails in details which are highlighted. The fragmentation of heavy\nquarks measured at HERA is consistent with that at LEP and hence supports the\nnotion of universality.", "category": "hep-ex" }, { "text": "OPERA neutrino oscillation search: status and perspectives: OPERA is a long-baseline experiment at the Gran Sasso laboratory (LNGS)\ndesigned to search for $\\nu_\\mu \\rightarrow \\nu_\\tau$ oscillations in\nappearance mode. OPERA took data from 2008 to 2012 with the CNGS neutrino beam\nfrom CERN. The data analysis is ongoing, with the goal of establishing\n$\\nu_\\tau$ appearance with high significance and improving the sensitivity to\nthe sterile neutrino search in the $\\nu_\\mu$ $\\rightarrow$ $\\nu_e$ appearance\nchannel. Current results will be presented and perspectives discussed.", "category": "hep-ex" }, { "text": "Search for eta_b in two-photon collisions at LEP II with the DELPHI\n detector: The pseudoscalar meson eta_b has been searched for in two-photon interactions\nat LEP II. The data sample corresponds to a total integrated luminosity of 617\npb^{-1} at centre-of-mass energies ranging from 161 to 209 GeV. Upper limits at\na confidence level of 95% on the product Gamma_{\\gamma\\gamma}(eta_b) x\nBR(eta_b) are 190, 470 and 660 eV/c^2 for the eta_b decaying into 4, 6 and 8\ncharged particles, respectively.", "category": "hep-ex" }, { "text": "Kinematical Reconstruction of the ttbar System Near its Threshold at\n Future e+e- Linear Colliders: We developed a new method for full kinematical reconstruction of the ttbar\nsystem near its threshold at future linear e+e- colliders. In the core of the\nmethod lies likelihood fitting which is designed to improve measurement\naccuracies of the kinematical variables that specify the final states resulting\nfrom ttbar decays. The improvement is demonstrated by applying this method to a\nMonte-Carlo ttbar sample generated with various experimental effects including\nbeamstrahlung, finite acceptance and resolution of the detector system, etc. A\npossible application of this method and its expected impact are also discussed.", "category": "hep-ex" }, { "text": "Search for Supersymmetry in Events with Large Missing Transverse\n Momentum, Jets, and at Least One Tau Lepton in 7 TeV Proton-Proton Collision\n Data with the ATLAS Detector: A search for supersymmetry (SUSY) in events with large missing transverse\nmomentum, jets, and at least one hadronically decaying tau lepton, with zero or\none additional light lepton (e/mu), has been performed using 4.7 fb-1 of\nproton-proton collision data at sqrt(s) = 7 TeV recorded with the ATLAS\ndetector at the Large Hadron Collider. No excess above the Standard Model\nbackground expectation is observed and a 95% confidence level visible\ncross-section upper limit for new phenomena is set. In the framework of\ngauge-mediated SUSY-breaking models, lower limits on the mass scale Lambda are\nset at 54 TeV in the regions where the stau is the next-to-lightest SUSY\nparticle (tan(beta) > 20). These limits provide the most stringent tests to\ndate of GMSB models in a large part of the parameter space considered.", "category": "hep-ex" }, { "text": "Recent Results from the KTeV Experiment: We present recent preliminary results from five decay channels. From the\n$K_L\\to\\pi^+\\pi^-\\gamma$ channel, we extract form factors for the CP violating\nM1 direct photon emission amplitude and the fraction of the total decay\namplitude that is due to direct emission. We have placed an upper limit on the\n$K_L\\to\\pi^0\\pi^0\\gamma$ branching ratio, and preliminary measurements of the\n$K_L\\to\\pi^{\\pm}e^{\\mp}\\nu e^+e^-$ and $\\pi^0\\to e^+e^-$ branching ratios are\npresented. Finally, we report measurements of both the branching ratio and the\nform factor parameters for the decay $K_L\\to e^+e^-\\gamma$.", "category": "hep-ex" }, { "text": "Search for supersymmetry in final states with disappearing tracks in\n proton-proton collisions at $\\sqrt{s}$ = 13 TeV: A search is presented for charged, long-lived supersymmetric particles in\nfinal states with one or more disappearing tracks. The search is based on data\nfrom proton-proton collisions at a center-of-mass energy of 13 TeV collected\nwith the CMS detector at the CERN LHC between 2016 and 2018, corresponding to\nan integrated luminosity of 137 fb$^{-1}$. The search is performed over final\nstates characterized by varying numbers of jets, b-tagged jets, electrons, and\nmuons. The length of signal-candidate tracks in the plane perpendicular to the\nbeam axis is used to characterize the lifetimes of wino- and higgsino-like\ncharginos produced in the context of the minimal supersymmetric standard model.\nThe d$E$/d$x$ energy loss of signal-candidate tracks is used to increase the\nsensitivity to charginos with a large mass and thus a small Lorentz boost. The\nobserved results are found to be statistically consistent with the\nbackground-only hypothesis. Limits on the pair production cross section of\ngluinos and squarks are presented in the framework of simplified models of\nsupersymmetric particle production and decay, and for electroweakino production\nbased on models of wino and higgsino dark matter. The limits presented are the\nmost stringent to date for scenarios with light third-generation squarks and a\nwino- or higgsino-like dark matter candidate capable of explaining the known\ndark matter relic density.", "category": "hep-ex" }, { "text": "Forward Jets, Dijets, and Subjets at the Tevatron: Recent new results on the determination of the rapidity dependence of the\ndifferential inclusive jet cross section, $$, as a\nfunction of jet $E_{T}$ in \\ppbar collisions at $\\sqrt{s}=1800$ GeV, measured\nby the D0 detector at the Tevatron, are presented along with the comparisons to\ntheoretical next-to-leading order (NLO) perturbative QCD predictions. Triple\ndifferential dijet cross sections, $$, at\n$\\sqrt{s}=1800$ GeV, as well as the new results on jet structure at\n$\\sqrt{s}=1800$ and 630 GeV, as measured by the CDF and D0 detectors, are also\ndiscussed.", "category": "hep-ex" }, { "text": "Observation of the $Y(4230)$ and a new structure in $e^+e^- \\rightarrow\n K^+K^-J/\u03c8$: The cross sections of $e^+e^- \\rightarrow K^+K^-J/\\psi$ at center-of-mass\nenergies from 4.127 to 4.600~GeV are measured based on 15.6 fb$^{-1}$ data\ncollected with the BESIII detector operating at the BEPCII storage ring. Two\nresonant structures are observed in the line shape of the cross sections. The\nmass and width of the first structure are measured to be\n($4225.3\\pm2.3\\pm21.5$) MeV and ($72.9\\pm6.1\\pm30.8$)~MeV, respectively. They\nare consistent with those of the established $Y(4230)$. The second structure is\nobserved for the first time with a statistical significance greater than\n8$\\sigma$, denoted as $Y(4500)$. Its mass and width are determined to be\n($4484.7\\pm13.3\\pm24.1$) MeV and ($111.1\\pm30.1\\pm15.2$) MeV, respectively. The\nfirst presented uncertainties are statistical and the second ones are\nsystematic. The product of the electronic partial width with the decay\nbranching fraction $ \\Gamma(Y(4230)\\to e^+ e^-) \\mathcal{B}(Y(4230) \\to K^+ K^-\nJ/\\psi)$ is reported.", "category": "hep-ex" }, { "text": "Photoproduction of Isolated Photons, Inclusively and with a Jet, at HERA: The photoproduction of isolated photons, both inclusive and together with a\njet, has been measured with the ZEUS detector at HERA using an integrated\nluminosity of $374\\, \\mathrm{pb}^{-1}$. Differential cross sections are\npresented in the isolated-photon transverse-energy and pseudorapidity ranges $6\n< E_T^\\gamma < 15$ GeV and $-0.7 < \\eta^\\gamma < 0.9,$ and for jet\ntransverse-energy and pseudorapidity ranges $4 < E_T^{jet} < 35$ GeV and $-1.5\n< \\eta^{jet} < 1.8,$ for exchanged-photon virtualities $Q^2 < 1$ GeV$^2$.\nDifferential cross sections are also presented for inclusive isolated-photon\nproduction as functions of the transverse energy and pseudorapidity of the\nphoton. Higher-order theoretical calculations are compared to the results.", "category": "hep-ex" }, { "text": "Search for pair-produced leptoquarks in e+e- interactions at sqrt(s) =\n 183 GeV: A search for pair-produced leptoquarks has been performed using a sample of\ne+e- collision events collected by the OPAL detector at LEP at e+e-\ncentre-of-mass energies of about 183 GeV. The data sample corresponds to an\nintegrated luminosity of 55.9 pb-1. The leptoquarks were assumed to be produced\nvia couplings to the photon and the Z0 and then to decay within a single\nfermion generation. No evidence for contributions from leptoquark pair\nproduction processes was observed. Lower limits on scalar and vector leptoquark\nmasses are obtained. The existing limits are improved in the region of large\ndecay branching ratio to quark-neutrino.", "category": "hep-ex" }, { "text": "phi2/alpha: We report the recent phi2/alpha results from Belle with KEKB accelerator and\nBabar with PEP-II accelerator. The analysis of B->pi pi, B->rho rho and B->rho\npi are included in this report. These b->u u_bar d decay modes are related to\nthe CKM angle phi2/alpha and the method of phi2/alpha extraction of\ncorresponding decay are also included. After combining all the decay modes, the\nconstraint of phi2/alpha is 100.2+15.0-8.8 degree.", "category": "hep-ex" }, { "text": "First measurements of absolute branching fractions of $\u039e_c^0$ at Belle: We present the first measurements of absolute branching fractions of\n$\\Xi_c^0$ decays into $\\Xi^- \\pi^+$, $\\Lambda K^- \\pi^+$, and $p K^- K^- \\pi^+$\nfinal states. The measurements are made using a data set comprising $(772\\pm\n11)\\times 10^{6}$ $B\\bar{B}$ pairs collected at the $\\Upsilon(4S)$ resonance\nwith the Belle detector at the KEKB $e^+e^-$ collider. We first measure the\nabsolute branching fraction for $B^- \\to \\bar{\\Lambda}_c^- \\Xi_c^0$ using a\nmissing-mass technique; the result is ${\\cal B}(B^- \\to \\bar{\\Lambda}_c^-\n\\Xi_c^0) = (9.51 \\pm 2.10 \\pm 0.88) \\times 10^{-4}$. We subsequently measure\nthe product branching fractions ${\\cal B}(B^- \\to \\bar{\\Lambda}_c^-\n\\Xi_c^0){\\cal B}(\\Xi_c^0 \\to \\Xi^- \\pi^+)$, ${\\cal B}( B^- \\to\n\\bar{\\Lambda}_c^- \\Xi_c^0) {\\cal B}(\\Xi_c^0 \\to \\Lambda K^- \\pi^+)$, and ${\\cal\nB}( B^- \\to \\bar{\\Lambda}_c^- \\Xi_c^0) {\\cal B}(\\Xi_c^0 \\to p K^- K^- \\pi^+)$\nwith improved precision. Dividing these product branching fractions by the\nresult for $B^- \\to \\bar{\\Lambda}_c^- \\Xi_c^0$ yields the following branching\nfractions: ${\\cal B}(\\Xi_c^0 \\to \\Xi^- \\pi^+)= (1.80 \\pm 0.50 \\pm 0.14)\\%$,\n${\\cal B}(\\Xi_c^0 \\to \\Lambda K^- \\pi^+)=(1.17 \\pm 0.37 \\pm 0.09)\\%$, and\n${\\cal B}(\\Xi_c^0 \\to p K^- K^- \\pi^+)=(0.58 \\pm 0.23 \\pm 0.05)\\%.$ For the\nabove branching fractions, the first uncertainties are statistical and the\nsecond are systematic. Our result for ${\\cal B}(\\Xi_c^0 \\to \\Xi^- \\pi^+)$ can\nbe combined with $\\Xi_c^0$ branching fractions measured relative to $\\Xi_c^0\n\\to \\Xi^- \\pi^+$ to yield other absolute $\\Xi_c^0$ branching fractions.", "category": "hep-ex" }, { "text": "Beam-Spin Asymmetries in the Azimuthal Distribution of Pion\n Electroproduction: A measurement of the beam-spin asymmetry in the azimuthal distribution of\npions produced in semi-inclusive deep-inelastic scattering off protons is\npresented. The measurement was performed using the {HERMES} spectrometer with a\nhydrogen gas target and the longitudinally polarized 27.6 GeV positron beam of\nHERA. The sinusoidal amplitude of the dependence of the asymmetry on the angle\n$\\phi$ of the hadron production plane around the virtual photon direction\nrelative to the lepton scattering plane was measured for $\\pi^+,\\pi^-$ and\n$\\pi^0$ mesons. The dependence of this amplitude on the Bjorken scaling\nvariable and on the pion fractional energy and transverse momentum is\npresented. The results are compared to theoretical model calculations.", "category": "hep-ex" }, { "text": "Recent Results of BABAR: The BABAR detector at SLAC's PEP-II storage ring has collected data\nequivalent to about 30.4 fb-1 through June 2001. Results on CP violation, and\nin particular searches for direct CP violation, and measurement of rare B\ndecays are presented.", "category": "hep-ex" }, { "text": "Search for a light CP-odd Higgs boson in the radiative decays of J/psi: We search for a light Higgs boson $A^0$ in the fully reconstructed decay\nchain of $J/\\psi \\rightarrow \\gamma A^0$, $A^0 \\rightarrow \\mu^+\\mu^-$ using\n$(225.0\\pm2.8)\\times10^6$ $J/\\psi$ events collected by the BESIII experiment.\nThe $A^0$ is a hypothetical CP-odd light Higgs boson predicted by many\nextensions of the Standard Model including two spin-0 doublets plus an extra\nsinglet. We find no evidence for $A^0$ production and set $90\\%$\nconfidence-level upper limits on the product branching fraction\n$\\mathcal{B}(J/\\psi \\rightarrow \\gamma A^0) \\times \\mathcal{B}(A^0 \\rightarrow\n\\mu^+\\mu^-)$ in the range of $(2.8-495.3)\\times 10^{-8}$ for $0.212 \\le m_{A^0}\n\\le 3.0$ GeV/c$^2$. The new limits are $5$ times below our previous results,\nand the nature of the $A^0$ is constrained to be mostly singlet.", "category": "hep-ex" }, { "text": "Measurements of Neutral B Decay Branching Fractions to K0S pi+ pi- Final\n States and the Charge Asymmetry of B0 --> K*+ pi-: We analyze the decay B0 -> K0s pi+ pi- using a sample of 232 million\nUpsilon(4S) -> BB decays collected with the BaBar detector at the SLAC PEP-II\nasymmetric-energy B factory. A maximum likelihood fit finds the following\nbranching fractions: BF(B0 -> K0 pi+ pi-) = (43.0 +/- 2.3 +/- 2.3) x 10^{-6},\nBF(B0 -> f0 (-> pi+ pi-) K0) = (5.5 +/- 0.7 +/- 0.5 +/- 0.3) x 10^{-6} and\nBF(B0 -> K*+ pi-) = (11.0 +/- 1.5 +/- 0.5 +/- 0.5) x 10^{-6}. For these\nresults, the first uncertainty is statistical, the second is systematic, and\nthe third (if present) is due to the effect of interference from other\nresonances. We also measure the CP-violating charge asymmetry in the decay B0\n-> K*+ pi-, A(B0 -> K*+ pi-) = -0.11 +/- 0.14 +/- 0.05.", "category": "hep-ex" }, { "text": "Search for Doubly Charmed Baryons Xi_cc^+ and Xi_cc^++ in BABAR: We search for the production of doubly charmed baryons in e^+e^-\nannihilations at or near a center-of-mass energy of 10.58 GeV, in a data sample\nwith an integrated luminosity of 232 fb^-1 recorded with the BABAR detector at\nthe PEP-II storage ring at the Stanford Linear Accelerator Center. We search\nfor Xi_cc^+ baryons in the final states Lambda_c^+K^-pi^+ and Xi_c^0pi^+, and\nXi_cc^++ baryons in the final states Lambda_c^+K^-pi^+pi^+ and Xi_c^0pi^+pi^+.\nWe find no evidence for the production of doubly charmed baryons.", "category": "hep-ex" }, { "text": "Measurement of the Top-antitop Production Cross Section in pp Collisions\n at sqrt(s)=7 TeV using the Kinematic Properties of Events with Leptons and\n Jets: A measurement of the top-antitop production cross section in proton-proton\ncollisions at a centre-of-mass energy of 7 TeV has been performed at the LHC\nwith the CMS detector. The analysis uses a data sample corresponding to an\nintegrated luminosity of 36 inverse picobarns and is based on the\nreconstruction of the final state with one isolated, high transverse-momentum\nelectron or muon and three or more hadronic jets. The kinematic properties of\nthe events are used to separate the top-antitop signal from W+jets and QCD\nmultijet background events. The measured cross section is 173 + 39 - 32 (stat.\n+ syst.) pb, consistent with standard model expectations.", "category": "hep-ex" }, { "text": "Status of Charm Flavor Physics: The role of charm in testing the Standard Model description of quark mixing\nand CP violation through measurements of lifetimes, decay constants and\nsemileptonic form factors is reviewed. Together with Lattice QCD, charm has the\npotential this decade to maximize the sensitivity of the entire flavor physics\nprogram to new physics. and pave the way for understanding physics beyond the\nStandard Model at the LHC in the coming decade. The status of indirect searches\nfor physics beyond the Standard Model through charm mixing, CP-violation and\nrare decays is also reported.", "category": "hep-ex" }, { "text": "Improved Measurement of the Reactor Antineutrino Flux at Daya Bay: This work reports a precise measurement of the reactor antineutrino flux\nusing 2.2 million inverse beta decay (IBD) events collected with the Daya Bay\nnear detectors in 1230 days. The dominant uncertainty on the neutron detection\nefficiency is reduced by 56% with respect to the previous measurement through a\ncomprehensive neutron calibration and detailed data and simulation analysis.\nThe new average IBD yield is determined to be\n$(5.91\\pm0.09)\\times10^{-43}~\\rm{cm}^2/\\rm{fission}$ with total uncertainty\nimproved by 29%. The corresponding mean fission fractions from the four main\nfission isotopes $^{235}$U, $^{238}$U, $^{239}$Pu, and $^{241}$Pu are 0.564,\n0.076, 0.304, and 0.056, respectively. The ratio of measured to predicted\nantineutrino yield is found to be $0.952\\pm0.014\\pm0.023$\n($1.001\\pm0.015\\pm0.027$) for the Huber-Mueller (ILL-Vogel) model, where the\nfirst and second uncertainty are experimental and theoretical model\nuncertainty, respectively. This measurement confirms the discrepancy between\nthe world average of reactor antineutrino flux and the Huber-Mueller model.", "category": "hep-ex" }, { "text": "Amplitude Analysis of the decay D^0 --> K^- K^+ pi^0: Using 385 fb^-1 of e^+e^- collisions at the CM energies of around 10.6 GeV\nrecorded by the BaBar experiment, we study the amplitudes of the singly\nCabibbo-suppressed decay D^0 --> K^- K^+ pi^0. We measure the strong phase\ndifference between the D0bar and D0 decays to the K^*(892)^+ K^- state to be\n-35.5 +/- 1.9 (stat) +/- 2.2 (syst) degrees, and their amplitude ratio to be\n0.599 +/- 0.013 (stat) +/- 0.011 (syst). We observe significant contributions\nfrom the Kpi and K^-K^+ scalar and vector amplitudes, and analyze the moments\nof the cosine of the helicity angle in these systems. We find no evidence for\ncharged, scalar kappa(800) state, nor for higher spin states. We also perform a\nmodel-independent partial wave analysis of the K^-K^+ system in a limited mass\nrange around 1 GeV/c^2. We study several models for Kpi S-wave amplitude, and\ndescribe which one is favored by our data.", "category": "hep-ex" }, { "text": "Reply to 'Corrections to the HARP-CDP Analysis of the LSND Neutrino\n Oscillation Backgrounds': The alleged mistakes in recent papers that reanalyze the backgrounds to the\n'LSND anomaly' do not exist. We maintain our conclusion that the significance\nof the 'LSND anomaly' is not 3.8 sigma but not larger than 2.3 sigma.", "category": "hep-ex" }, { "text": "An optimal method of moments to measure the charge asymmetry at the\n $Z^0$: Parity violation at LEP or SLC can be measured through the charge asymmetry.\nAn optimal method of moments is developed here to measure this asymmetry, as\nwell as similar asymmetries. This method is equivalent to the likelihood fit.\nIt is simpler in use, as it gives analytical formulas for both the asymmetry\nand its statistical error. These formulas give the dependence of the accuracy\non the experimental angular acceptance explicitly.", "category": "hep-ex" }, { "text": "Bounds on the width, mass difference and other properties of X(3872) -->\n pi+pi-J/psi decays: We present results from a study of X(3872) --> pi+pi- J/psi decays produced\nvia exclusive B--> K X(3872) decays. We determine the mass to be M_X(3872)=\n(3871.84\\pm 0.27 (stat)\\pm 0.19 (syst)) MeV, a 90% CL upper limit on the\nnatural width of Gamma_X(3872)<1.2 MeV, the product branching fraction Bf(B+->\nK+X(3872))xBf(X(3872)-->pi+pi-J/psi)=(8.61 \\pm 0.82(stat) \\pm 0.52 (syst))\nx10^{-6}, and a ratio of branching fractions Bf(B0--> K0 X(3872))/BF(B+--> K+\nX(3872))=0.50\\pm 0.14(stat)\\pm0.04(syst). The difference in mass between the\nX(3872)-->pi+pi-J/psi signals in B+ and B0 decays is Delta M_{X(3872)= (-0.69\n\\pm 0.97 (stat)} \\pm 0.19 (syst)) MeV. A search for a charged partner of the\nX(3872) in the decays Bbar0-->K- X+ or B+-->K0X+, X+-->pi+pi0 J/psi resulted in\nupper limits on the product branching fractions for these processes that are\nwell below expectations for the case that the X(3872) is the neutral member of\nan isospin triplet. In addition, we examine possible J^{PC} quantum number\nassignments for the X(3872) based on comparisons of angular correlations\nbetween final state particles in X(3872)-->pi+pi-J/psi decays with simulated\ndata for J^{PC} values of 1^{++} and 2^{-+}. We examine the influence of\nrho-omega interference in the M(pi+pi-) spectrum. The analysis is based on a\n711fb^{-1} data sample that contains 772 million BBbar meson pairs collected at\nthe Upsilon(4S) resonance in the Belle detector at the KEKB e+e- collider.", "category": "hep-ex" }, { "text": "Search for the B_c Meson in Hadronic Z^0 Decays: A search for decays of the B_c meson was performed using data collected from\n1990-1995 with the OPAL detector on or near the Z peak at LEP. The decay\nchannels B_c^+ -> J/psi pi^+, B_c^+ -> J/psi a_1^+ and B_c^+ -> J/psi ell^+ nu\nwere investigated, where ell denotes an electron or a muon. Two candidates are\nobserved in the mode B_c^+ -> J/psi pi^+, with an estimated background of (0.63\n+/- 0.20) events. The weighted mean of the masses of the two candidates is\n(6.32 +/- 0.06) GeV/c^2, which is consistent with the predicted mass of the B_c\nmeson. One candidate event is observed in the mode B_c^+ -> J/psi ell^+ nu with\nan estimated background of (0.82 +/- 0.19) events. No candidate events are\nobserved in the B_c^+ -> J/psi a_1^+ decay mode, with an estimated background\nof (1.10 +/- 0.22) events. Upper bounds at the 90% confidence level are set on\nthe production rates for these processes.", "category": "hep-ex" }, { "text": "Study of Jet Shapes in Inclusive Jet Production in ppbar Collisions at\n sqrt{s} = 1.96 TeV: We report on a study of jet shapes in inclusive jet production in $p \\bar{p}$\ncollisions at $\\sqrt{s} = 1.96 {\\rm TeV}$ using the upgraded Collider Detector\nat Fermilab in Run II (CDF II) based on an integrated luminosity of $170 \\rm\npb^{-1}$. Measurements are carried out on jets with rapidity $0.1 < |Y^{\\rm\njet}| < 0.7$ and transverse momentum 37 GeV/c $< P_T^{\\rm jet} < 380$ GeV/c.\nThe jets have been corrected to the hadron level. The measured jet shapes are\ncompared to leading-order QCD parton-shower Monte Carlo predictions as\nimplemented in the PYTHIA and HERWIG programs. PYTHIA, tuned to describe the\nunderlying event as measured in CDF Run I, provides a better description of the\nmeasured jet shapes than does PYTHIA or HERWIG with their default parameters.", "category": "hep-ex" }, { "text": "Measurement of the very rare $K^+\\rightarrow\u03c0^+\u03bd\\bar\u03bd$ decay: The NA62 experiment reports the branching ratio measurement BR$(K^+\n\\rightarrow \\pi^+ \\nu\\bar{\\nu}) = (10.6^{+4.0}_{-3.4} |_{\\rm stat} \\pm 0.9_{\\rm\nsyst}) \\times 10 ^{-11}$ at 68% CL, based on the observation of 20 signal\ncandidates with an expected background of 7.0 events from the total data sample\ncollected at the CERN SPS during 2016-2018. This provides evidence for the very\nrare $K^+ \\rightarrow \\pi^+ \\nu\\bar{\\nu}$ decay, observed with a significance\nof 3.4$\\sigma$. The experiment achieves a single event sensitivity of\n$(0.839\\pm 0.054)\\times 10^{-11}$, corresponding to 10.0 events assuming the\nStandard Model branching ratio of $(8.4\\pm1.0)\\times10^{-11}$. This measurement\nis also used to set limits on BR($K^+ \\to \\pi^+ X$), where $X$ is a scalar or\npseudo-scalar particle. Details are given of the analysis of the 2018 data\nsample, which corresponds to about 80% of the total data sample.", "category": "hep-ex" }, { "text": "Search for magnetic monopoles and stable particles with high electric\n charges in 8 TeV $pp$ collisions with the ATLAS detector: A search for highly ionizing particles produced in proton-proton collisions\nat 8 TeV center-of-mass energy is performed by the ATLAS collaboration at the\nCERN Large Hadron Collider. The dataset used corresponds to an integrated\nluminosity of 7.0 fb$^{-1}$. A customized trigger significantly increases the\nsensitivity, permitting a search for such particles with charges and energies\nbeyond what was previously accessible. No events were found in the signal\nregion, leading to production cross section upper limits in the mass range\n200--2500 GeV for magnetic monopoles with magnetic charge in the range\n$0.5g_{D}<|g|<2.0g_{D}$, where $g_{D}$ is the Dirac charge, and for stable\nparticles with electric charge in the range $10<|z|<60$. Model-dependent limits\nare presented in given pair-production scenarios, and model-independent limits\nare presented in fiducial regions of particle energy and pseudorapidity.", "category": "hep-ex" }, { "text": "Investigation of Colour Reconnection in WW Events with the DELPHI\n detector at LEP-2: In the reaction e+e- -> WW -> (q_1 qbar_2)(q_3 qbar_4) the usual\nhadronization models treat the colour singlets q_1 qbar_2 and q_3 qbar_4 coming\nfrom two W bosons independently. However, since the final state partons may\ncoexist in space and time, cross-talk between the two evolving hadronic systems\nmay be possible during fragmentation through soft gluon exchange. This effect\nis known as Colour Reconnection. In this article the results of the\ninvestigation of Colour Reconnection effects in fully hadronic decays of W\npairs in DELPHI at LEP are presented. Two complementary analyses were\nperformed, studying the particle flow between jets and W mass estimators, with\nnegligible correlation between them, and the results were combined and compared\nto models. In the framework of the SK-I model, the value for its kappa\nparameter most compatible with the data was found to be: kappa_{SK-I} =\n2.2^{+2.5}_{-1.3} corresponding to the probability of reconnection P_{reco} to\nbe in the range 0.31 < P_{reco} < 0.68 at 68% confidence level with its best\nvalue at 0.52.", "category": "hep-ex" }, { "text": "Search for Pair Production of Supersymmetric Top Quarks in Dilepton\n Events from $p\\bar{p}$ Collisions at $\\sqrt{s}$ = 1.96 TeV: We present the results of a search for pair production of the supersymmetric\npartner of the top quark (the stop quark $\\tilde{t}_{1}$) decaying to a\n$b$-quark and a chargino $\\chargino$ with a subsequent $\\chargino$ decay into a\nneutralino $\\neutralino$, lepton $\\ell$, and neutrino $\\nu$. Using a data\nsample corresponding to 2.7 fb$^{-1}$ of integrated luminosity of $p\\bar{p}$\ncollisions at $\\sqrt{s} = 1.96$ TeV collected by the CDF II detector, we\nreconstruct the mass of candidate stop events and fit the observed mass\nspectrum to a combination of standard model processes and stop quark signal. We\nfind no evidence for $\\pairstop$ production and set 95% C.L. limits on the\nmasses of the stop quark and the neutralino for several values of the chargino\nmass and the branching ratio ${\\cal B}(\\chargino\\to\\neutralino\\ell^{\\pm}\\nu)$.", "category": "hep-ex" }, { "text": "Comparison of D --> K_s^0 pi and D --> K_L^0 pi Decay Rates: We present measurements of D -> K0_S pi and D -> K0_L pi branching fractions\nusing 281 pb-1 of psi(3770) data at the CLEO-c experiment. We find that B(D0 ->\nK0_S pi0) is larger than B(D0 -> K0_L pi0), with an asymmetry of R(D0) = 0.108\n+- 0.025 +- 0.024. For B(D+ -> K0_S pi+) and B(D+ -> K0_L pi+), we observe no\nmeasurable difference; the asymmetry is R(D+) = 0.022 +- 0.016 +- 0.018. The D0\nasymmetry is consistent with the value based on the U-spin prediction A(D0 ->\nK0 pi0)/A(D0 -> K0bar pi0) = -tan^2(theta_C), where theta_C is the Cabibbo\nangle.", "category": "hep-ex" }, { "text": "Charmless Hadronic B Decays at CLEO: The CLEO collaboration has studied two-body charmless hadronic decays of $B$\nmesons into final states containing two pseudo-scalar mesons, or a\npseudo-scalar and a vector meson. We summarize and discuss results presented\nduring the winter/spring 1999 conference season, and provide a brief outlook\ntowards future attractions to come.\n In particular, CLEO presented preliminary results on the decays $B^\\pm \\to\n\\pi^\\pm\\rho^0$ ($Br(B^\\pm \\to \\pi^\\pm\\rho^0) = (1.5 \\pm 0.5 \\pm 0.4)\\times\n10^{-5}$), $B\\to \\pi^\\pm\\rho^\\mp$ ($Br(B\\to\n\\pi^\\pm\\rho^\\mp)=(3.5^{+1.1}_{-1.0}\\pm 0.5)\\times 10^{-5}$), $B\\to \\pi^\\pm\nK^{\\star\\mp}$ ($Br(B\\to \\pi^\\pm K^{\\star\\mp}) =\n(2.2^{+0.8+0.4}_{-0.6-0.5})\\times 10^{-5}$), and $B^\\pm \\to K^\\pm \\pi^0$\n($Br(B^\\pm \\to K^\\pm \\pi^0) = (1.5 \\pm 0.4 \\pm 0.3) \\times 10^{-5}$) at DPF99,\nAPS99, APS99, and ICHEP98 respectively. None of these decays had been observed\npreviously. The first two of these constitute the first observation of hadronic\n$b\\to u$ transitions. In addition, CLEO presented preliminary updates on a\nlarge number of previously published branching fractions and upper limits.", "category": "hep-ex" }, { "text": "Pion spectra in Ar+Sc interactions at SPS energies: This contribution discusses recent results from analysis of Ar+Sc\ninteractions recorded with the NA61/SHINE detector at six beam momenta: 13A,\n19A, 30A, 40A, 75A, 150A GeV/c at the CERN SPS. Rapidity and transverse mass\nspectra of pions obtained with the \"h-\" analysis method are presented and\ncompared to results from p+p, Be+Be and Pb+Pb collisions.", "category": "hep-ex" }, { "text": "Real time data analysis with the ATLAS Trigger at the LHC in Run-2: The trigger selection capabilities of the ATLAS detector have been\nsignificantly enhanced for the LHC Run- 2 in order to cope with the higher\nevent rates and with the large number of simultaneous interactions (pile-up)\nper protonproton bunch crossing. A new hardware system, designed to analyse\nreal time event-topologies at Level-1 came to full use in 2017. A\nhardware-based track reconstruction system, expected to be used real-time in\n2018, is designed to provide track information to the high-level software\ntrigger at its full input rate. The high-level trigger selections are largely\nrelying on offline-like reconstruction techniques, and in some cases\nmultivariate analysis methods. Despite the sudden change in LHC operations\nduring the second half of 2017, which caused an increase in pile-up and\ntherefore also in CPU usage of the trigger algorithms, the set of triggers (so\ncalled trigger menu) running online has undergone only minor modifications\nthanks to the robustness and redundancy of the trigger system, and the use of a\nlevelling luminosity scheme in agreement with LHC and other experiments. This\npresentation gives a brief yet comprehensive review of the real-time\nperformance of the ATLAS trigger system in 2017. Considerations will be\npresented on the most relevant parameters of the trigger (efficiency to collect\nsignal and output data rate) as well as details on some aspects of the\nalgorithms which are run real-time on the High Level Trigger CPU farm.", "category": "hep-ex" }, { "text": "Observation of charmonium pairs produced exclusively in $pp$ collisions: A search is performed for the central exclusive production of pairs of\ncharmonia produced in proton-proton collisions. Using data corresponding to an\nintegrated luminosity of $3{\\rm\\ fb}^{-1}$ collected at centre-of-mass energies\nof 7 and 8 TeV, $J/\\psi J/\\psi$ and $J/\\psi\\psi(2S)$ pairs are observed, which\nhave been produced in the absence of any other activity inside the LHCb\nacceptance that is sensitive to charged particles in the pseudorapidity ranges\n$(-3.5,-1.5)$ and $(1.5,5.0)$. Searches are also performed for pairs of P-wave\ncharmonia and limits are set on their production. The cross-sections for these\nprocesses, where the dimeson system has a rapidity between 2.0 and 4.5, are\nmeasured to be $$ \\begin{array}{rl} \\sigma^{J/\\psi J/\\psi} &= 58\\pm10{(\\rm\nstat)} \\pm 6{(\\rm syst)} {\\rm\\ pb} , \\\\ \\sigma^{J/\\psi\\psi(2S)} &= 63\n^{+27}_{-18}{(\\rm stat)}\\pm 10{(\\rm syst)} {\\rm\\ pb} , \\\\\n\\sigma^{\\psi(2S)\\psi(2S)} &< 237 {\\rm\\ pb}, \\\\ \\sigma^{\\chi_{c0}\\chi_{c0}} &<\n69 {\\rm\\ nb}, \\\\ \\sigma^{\\chi_{c1}\\chi_{c1}} &< 45 {\\rm\\ pb}, \\\\\n\\sigma^{\\chi_{c2}\\chi_{c2}} &< 141 {\\rm\\ pb}, \\\\ \\end{array} $$ where the upper\nlimits are set at the 90% confidence level. The measured $J/\\psi J/\\psi$ and\n$J/\\psi\\psi(2S)$ cross-sections are consistent with theoretical expectations.", "category": "hep-ex" }, { "text": "FunctionalObjects.h: Using Symbolic Syntax in C++ Programs: functionalObjects.h allows the C++ programmer performing common mathematical\ncalculations to use a more symbolic syntax rather than an algorithmic syntax.\nThis is not as ambitious as a symbolic manipulation program such as\nMathematica; it is more like having the ability to drop a very simple\nMathematica statement into a C++ program.", "category": "hep-ex" }, { "text": "Recent Studies of Exotic Hadrons at the LHCb Experiment: Recent results on studies of exotic hadrons at the LHCb experiment are\nsummarised. These are the observation of new resonances decaying to J/$\\psi\nK^{+}$ and J/$\\psi\\phi$, evidence of a J/$\\psi\\Lambda$ structure and\nobservation of excited $\\Xi^{-}$ states in the $\\Xi_{b}^{-}\\to J/\\psi \\Lambda\nK^{-}$ decay and the study of $B_{s}^{0}\\to J/\\psi\\pi^{+}\\pi^{-}K^{+}K^{-}$\ndecays.", "category": "hep-ex" }, { "text": "Properties of the X(3872) at Belle: We report recent results on the properties of the X(3872) produced via the B+\n--> K+ X(3872) decay process. We observe X -->pi+pi-pi0 J/psi decays where the\n3pi invariant masses cluster near the upper kinematic boundary suggesting that\nthey originate from sub-threshold decays to virtual omega(782) mesons. This is\nconsistent with expectations for a DD*-bar bound state interpretation for the\nX(3872). In addition, we constrain the possible charmonium-state assignments\nfor this particles. Results are obtained from a 253/fb data sample that\ncontains 274 million BB-barr pairs that was collected near the Upsilon(4S)\nresonance with the Belle detector at the KEKB asymmetric energy e+e- collider.", "category": "hep-ex" }, { "text": "SM+Top at the LHC: These proceedings highlight a selection of recent results by the ATLAS, CMS\nand LHCb collaborations. The majority of the featured analyses make use of the\nlarge set of $\\sqrt{s}=13$ TeV proton-proton collision data collected during\nthe successful second run of the LHC. A particular focus is placed on analyses\nof Standard Model processes involving either hadronic jets or W/Z bosons.\nSearches and cross-section measurements involving top quark signatures are also\ngiven prominence, as are those targeting highly boosted objects such as W/Z and\nH bosons, and which feature the use of large-radius jets and substructure\ntechniques.", "category": "hep-ex" }, { "text": "Up and Down Quark Structure of the Proton: We measure proton structure parameters sensitive primarily to valence quarks\nusing 8.6 fb$^{-1}$ of data collected by the D0 detector in $\\sqrt{s}=1.96$ TeV\n$p\\bar{p}$ collisions at the Fermilab Tevatron. We exploit the property of the\nforward-backward asymmetry in dilepton events to be factorized in to distinct\nstructure parameters and electroweak quark-level asymmetries. Contributions to\nthe asymmetry from $s$, $c$ and $b$ quarks, as well as from $u$ and $d$ quarks,\nare suppressed allowing valence $u$ and $d$ quarks to be separately determined.\nWe find and $u$ to $d$ quark ratio near the peak values in the quark density\ndistributions that is smaller than predictions from modern parton distribution\nfunctions.", "category": "hep-ex" }, { "text": "Dalitz Plot Study of B0 --> K+K-K0S Decays: We present a study of the dynamics in B0 --> K+ K- K0S decays with\napproximately 230 million BBbar events collected by the BABAR detector at SLAC.\nWe find that the Dalitz plot distribution is best parameterized with the phi\nK0S mode, an S-wave K+ K- resonance near 1500 MeV/c^2, and a large non-resonant\ncontribution. We set limits on resonances not included in our model, and study\nmodels for the non-resonant contribution.", "category": "hep-ex" }, { "text": "Combined measurements of the properties of the Higgs boson using the\n ATLAS detector: The combined measurement of the mass, couplings and spin-CP properties of the\nrecently discovered Higgs boson obtained with the ATLAS detector using up to\n$25$ fb$^{-1}$ of $7$ TeV and $8$ TeV $pp$ collision data is reviewed.", "category": "hep-ex" }, { "text": "Production of $\u03c0^{0}$, $K^{\\pm}$ and $\u03b7$ mesons in Pb-Pb and pp\n collisions at $\\sqrt{s_{\\rm NN}}=$2.76 TeV measured with the ALICE detector\n at the LHC: One of the key signatures of the Quark-Gluon Plasma (QGP) is the modification\nof hadron transverse momentum differential cross-sections in heavy-ion\ncollisions (HIC) as compared to proton-proton (pp) collisions. Suppression of\nhadron production at high transverse momenta ($p_{\\rm T}$) in HIC has been\nexplained by the energy loss of the partons produced in the hard scattering\nprocesses which traverse the deconfined quantum chromodynamic (QCD) matter. The\ndependence of the observed suppression on the $p_{\\rm T}$ of the measured\nhadron towards higher $p_{\\rm T}$ is an important input for the theoretical\nunderstanding of jet quenching effects in the QGP and the nature of the energy\nloss, while suppression towards lower $p_{\\rm T}$ gives information about\ncollective behaviour. The ALICE experiment at the Large Hadron Collider (LHC)\nperforms a variety of measurements including the spectra of neutral mesons and\nkaons at mid-rapidity in a wide $p_{\\rm T}$ range in pp, p-Pb and Pb-Pb\ncollisions. An overview of ALICE results in HIC and pp collisions at\n$\\sqrt{s_{NN}}=$2.76 TeV of neutral pions, kaons and eta mesons as a function\nof transverse momentum ($p_{\\rm T}$) and centrality will be presented. Ratios\n$\\eta$/$\\pi^{0}$, $K^{\\pm}$/$\\pi^{\\pm}$ as well as comparisons to model\ncalculations will also be discussed.", "category": "hep-ex" }, { "text": "A study of time-dependent CP-violating asymmetries in B0 --> J/psi K0S\n and B0 --> psi(2S) K0S decays: BABAR has studied the time dependent asymmetries in the the decays B0 ->\nJ/psi K0S and B0 -> psi(2S) K0S in a data set of 9.0 fb^-1 taken at the\nY(4S)resonance. In these channels we reconstruct 168 events of which 120 are\nflavor tagged and used in a likelihood fit where we determine sin2beta. The\nflavor of the other neutral $B$ mesons is tagged using information primarily\nfrom identified leptons and Kaons. A neural network is used to recover events\nwithout any clear Kaon or lepton signature. A preliminary result of\nsin2beta=0.12+/-0.37+/-0.09 is obtained.", "category": "hep-ex" }, { "text": "Search for $B \\to \u03c0\\ell^+\\ell^-$ Decays at Belle: We present a search for the B-> pi e^+ e^- and B-> pi \\mu^+ \\mu^- decays,\nwith a data sample of 657 million BBbar pairs collected with the Belle detector\nat the KEKB $e^+e^-$ collider. Signal events are reconstructed from a charged\nor a neutral pion candidate and a pair of oppositely charged electrons or\nmuons. No significant signal is observed and we set the upper limit on the\nisospin-averaged branching fraction BF(B -> \\pi \\ell^+\\ell^-) < 6.2x10^-8 at\nthe 90% confidence level.", "category": "hep-ex" }, { "text": "A Vision of Nuclear and Particle Physics: This paper will consist of a selected, personal view of some of the issues\nassociated with the intersections of nuclear and particle physics. As well as\ntouching on the recent developments we will attempt to look at how those\naspects of the subject might evolve over the next few years.", "category": "hep-ex" }, { "text": "Comparative overview of differential measurements at ATLAS and CMS: The study of the top quark has a central role for both the ATLAS and CMS\nexperiments. The measurement of the $t\\bar{t}$ production differential cross\nsection, in particular, is sensitive to existence of new resonances, it is a\nstringent test of perturbative QCD calculations and it is used to improve the\nmodelling of $t\\bar{t}$ production. ATLAS and CMS provided a large number of\nresults during the last years at $\\sqrt{s}$=7, 8, 13 TeV, in different regions\nof the phase space, considering different channels and topology and measuring\nthe cross section as a function of the kinematic variables of the $t\\bar{t}$\nsystem, the top quarks and/or their decay products. Even if the individual\nsteps are dependent on the specific analysis all the differential cross section\nmeasurements proceed through the same workflow: the event selection, the\nbackground determination, the reconstruction of the $t\\bar{t}$ system, the\ndefinition of the fiducial phase space, the unfolding applied to remove the\neffect of limited acceptance and resolution of the detector and the evaluation\nof the systematic uncertainties. In the following I will focus on the\ntechniques used by ATLAS and CMS to perform some of these steps while\npresenting a selection of recent results by the two experiments.", "category": "hep-ex" }, { "text": "Search for magnetic monopoles and stable particles with high electric\n charges in 8 TeV $pp$ collisions with the ATLAS detector: A search for highly ionizing particles produced in proton-proton collisions\nat 8 TeV center-of-mass energy is performed by the ATLAS collaboration at the\nCERN Large Hadron Collider. The dataset used corresponds to an integrated\nluminosity of 7.0 fb$^{-1}$. A customized trigger significantly increases the\nsensitivity, permitting a search for such particles with charges and energies\nbeyond what was previously accessible. No events were found in the signal\nregion, leading to production cross section upper limits in the mass range\n200--2500 GeV for magnetic monopoles with magnetic charge in the range\n$0.5g_{D}<|g|<2.0g_{D}$, where $g_{D}$ is the Dirac charge, and for stable\nparticles with electric charge in the range $10<|z|<60$. Model-dependent limits\nare presented in given pair-production scenarios, and model-independent limits\nare presented in fiducial regions of particle energy and pseudorapidity.", "category": "hep-ex" }, { "text": "Recent Progress and Puzzles in Charmonium Physics: While the charmonium model has been effective in describing ccbar bound\nmesons, there have been many recently discovered charmonium-like states it\ncannot accommodate. Here I provide a review of recent results from the\nB-factories including the X(3872), three new particles in the mass range near\n3.93 GeV, and four new resonances in initial state radiation (ISR) decays.", "category": "hep-ex" }, { "text": "Study of the lineshape of $X(3872)$ using $B$ decays to\n $D^0\\overline{D}{}^{*0}K$: We present a study of the $X(3872)$ lineshape in the decay $B \\to X(3872)K\\to\nD^0\\overline{D}{}^{*0}K$ using a data sample of $772\\times 10^6$\n$B\\overline{B}$ pairs collected at the $\\Upsilon(4S)$ resonance with the Belle\ndetector at the KEKB asymmetric-energy $e^+e^-$ collider. The peak near the\nthreshold in the $D^0\\overline{D}{}^{*0}$ invariant mass spectrum is fitted\nusing a relativistic Breit-Wigner lineshape. We determine the mass and width\nparameters to be $m = 3873.71 ^{+0.56}_{-0.50} ({\\rm stat}) \\pm0.13 ({\\rm\nsyst}) ~{\\rm MeV}/c^2$ and $\\Gamma_0 = 5.2 ^{+2.2}_{-1.5} ({\\rm stat}) \\pm 0.4\n({\\rm syst})~{\\rm MeV}$, respectively. The branching fraction is found to be\n${\\cal B} (B^+\\to X(3872)K^+) \\times {\\cal{B}}(X(3872) \\to\nD^0\\overline{D}{}^{*0}) = (0.97 ^{+0.21}_{-0.18} ({\\rm stat}) \\pm 0.10 ({\\rm\nsyst})) \\times 10^{-4}$. The signal from $B^0$ decays is observed for the first\ntime with $5.2\\sigma$ significance, and the ratio of branching fractions\nbetween charged and neutral $B$ decays is measured to be ${\\cal B}(B^0\\to\nX(3872)K^0)/{\\cal B}(B^+ \\to X(3872)K^+) = 1.34^{+0.47}_{-0.40} ({\\rm stat})\n^{+0.10}_{-0.12} ({\\rm syst})$. The peak is also studied using a Flatt\\'{e}\nlineshape. We determine the lower limit on the $D\\overline{D}{}^{*}$ coupling\nconstant $g$ to be $0.075$ at 95% credibility in the parameter region where the\nratio of $g$ to the mass difference from the $D^0\\overline{D}{}^{*0}$ threshold\nis equal to $-15.11~{\\rm GeV}^{-1}$, as measured by LHCb.", "category": "hep-ex" }, { "text": "Evidence for Direct CP Violation from Dalitz-plot analysis of B+/- ->\n K+/- pi+/- pi-/+: We report a Dalitz-plot analysis of the charmless hadronic decays of charged\nB mesons to the final state K+/- pi+/- pi-/+. Using a sample of 383.2 +/- 4.2\nmillion BBbar pairs collected by the BaBar detector, we measure CP-averaged\nbranching fractions and direct CP asymmetries for intermediate resonant and\nnonresonant contributions. We find evidence for direct CP violation in the\ndecay B+ -> rho0(770) K+, with a CP violation parameter A_CP = (+44 +/- 10 +/-\n4 +5,-13)%.", "category": "hep-ex" }, { "text": "Measurement of neutrino oscillations by means of a high density detector\n on the atmospheric neutrino beam: A high-density calorimeter, consisting of magnetized iron planes interleaved\nby RPCs, as tracking and timing devices, is a good candidate for a next\ngeneration experiment on atmospheric neutrinos. With 34 kt of mass and in four\nyears of data taking, this experiment will be sensitive to $\\nu_\\mu \\to \\nu_x$\noscillation with $\\Delta m^2 > 6 \\times 10^{-5}$ and mixing near to maximal and\nfully cover the region of oscillation parameters suggested by Super-Kamiokande\nresults. Moreover, the experimental method will enable to measure the\noscillation parameters from the modulation of the L/E spectrum ($\\nu_\\mu$\ndisappearance). For $\\Delta m^2 > 3 \\times 10^{-3}$ eV$^2$, this experiment can\nalso establish whether the oscillation occurs into a tau or a sterile neutrino,\nby looking for an excess of muon-less events at high energies produced by\nupward-going tau neutrinos ($\\nu_\\tau$ appearance).", "category": "hep-ex" }, { "text": "Muon Identification at ATLAS and CMS: Muonic final states will provide clean signatures formany physics processes\nat the LHC. The two LHC experiments ATLAS and CMS will be able to identify\nmuons with a high reconstruction efficiency above 96% and a high transverse\nmomentum resolution better than 2% for transverse momenta below 400 GeV/c and\nabout 10% at 1 TeV/c. The two experiments follow complentary concepts of muon\ndetection. ATLAS has an instrumented air-toroid mangetic system serving as a\nstand-alone muon spectrometer. CMS relies on high bending power and momentum\nresolution in the inner detector, and uses an iron yoke to increase its\nmagnetic field. The iron yoke is instrumented with chambers used for muon\nidentification. Therefore, muon momenta can only be reconstructed with high\nprecision by combining inner-detector information with the data from the muon\nchambers.", "category": "hep-ex" }, { "text": "Diphoton resonance at e+e- and photon colliders: In this note, I will review the opportunities offered by the hint of a new\nresonance observed at LHC for future e+e- TeV linear collider (LC) projects.\nThis discussion is mainly influenced by two specific scenarios of physics which\nassume either a (pseudo-)scalar or a tensor resonance, but these estimates can\nbe used in most scenarios. I envisage either a photon collider, which has a\nguaranteed signal with the LHC observation, or a standard e+e- collider, more\nstraightforward to implement. After a detailed study of the heavy graviton\nscenario, I conclude that at a TeV LC, high accuracy measurements, including\nrare modes, allow to unambiguously establish the origin of this resonance. Also\nenvisaged in some detail is a radion scenario which illustrates the production\nof a scalar. The role of an LC for precision measurements on Higgs and top\ncouplings is recalled in the context of the Randall Sundrum model.", "category": "hep-ex" }, { "text": "Dark Matter Benchmark Models for Early LHC Run-2 Searches: Report of the\n ATLAS/CMS Dark Matter Forum: This document is the final report of the ATLAS-CMS Dark Matter Forum, a forum\norganized by the ATLAS and CMS collaborations with the participation of experts\non theories of Dark Matter, to select a minimal basis set of dark matter\nsimplified models that should support the design of the early LHC Run-2\nsearches. A prioritized, compact set of benchmark models is proposed,\naccompanied by studies of the parameter space of these models and a repository\nof generator implementations. This report also addresses how to apply the\nEffective Field Theory formalism for collider searches and present the results\nof such interpretations.", "category": "hep-ex" }, { "text": "Charm Decays Within the Standard Model and Beyond: The charm quark has unique properties that make it a very important probe of\nmany facets of the Standard Model. New experimental information on charm decays\nis becoming available from dedicated experiments at charm factories, and\nthrough charm physics programs at the b-factories and hadron machines. In\nparallel, theorists are working on matrix element calculations based on\nunquenched lattice QCD, that can be validated by experimental measurements and\naffect our ultimate knowledge of the quark mixing parameters. Recent\npredictions are compared with corresponding experimental data and good\nagreement is found. Charm decays can also provide unique new physics\nsignatures; the status of present searches is reviewed. Finally, charm data\nrelevant for improving beauty decay measurements are presented.", "category": "hep-ex" }, { "text": "Evidence for a bottom baryon resonance Lambda_b* in CDF data: Using data from proton-antiproton collisions at Ecms=1.96 TeV recorded by the\nCDF II detector at the Fermilab Tevatron, evidence for the excited resonance\nstate Lambda_b* is presented in its Lambda_b0 pi+ pi- decay, followed by the\nLambda_b0 -->Lambda_c+ (-->proton K- pi+) pi- decays. The analysis is based on\na data sample corresponding to an integrated luminosity of 9.6/fb collected by\nan online event selection based on charged-particle tracks displaced from the\nproton-antiproton interaction point. The significance of the observed signal is\n3.5 Gaussian sigmas. The mass of the observed state is found to be 5919.22 +-\n0.76 MeV in agreement with similar findings in proton-proton collision\nexperiments.", "category": "hep-ex" }, { "text": "Search for a W' Boson via the Decay Mode W' -> mu nu in 1.8 TeV p-pbar\n Collisions: We report the results of a search for a W' boson produced in p-pbar\ncollisions at a center-of-mass energy of 1.8 TeV using a 107 pb-1 data sample\nrecorded by the Collider Detector at Fermilab. We consider the decay channel W'\n-> mu nu and search for anomalous production of high transverse mass mu-nu\nlepton pairs. We observe no excess of events above background and set limits on\nthe rate of W' boson production and decay relative to Standard Model W boson\nproduction and decay using a fit of the transverse mass distribution observed.\nIf we assume Standard Model strength couplings of the W' boson to quark and\nlepton pairs, we exclude a W' boson with invariant mass less than 660 GeV/c**2\nat 95% confidence level.", "category": "hep-ex" }, { "text": "Observation of new $\u039e_c^0$ baryons decaying to $\u039b_c^+ K^-$: The $\\Lambda_c^+K^-$ mass spectrum is studied with a data sample of $pp$\ncollisions at a centre-of-mass energy of 13 TeV corresponding to an integrated\nluminosity of 5.6 fb$^{-1}$ collected by the LHCb experiment. Three $\\Xi_c^0$\nstates are observed with a large significance and their masses and natural\nwidths are measured to be \\begin{eqnarray*} m(\\Xi_c(2923)^0)&=& 2923.04 \\pm\n0.25 \\pm 0.20 \\pm 0.14 ~\\mathrm{MeV}, \\Gamma(\\Xi_c(2923)^0) &=& 7.1 \\pm 0.8 \\pm\n1.8 ~\\mathrm{MeV}, \\end{eqnarray*} \\begin{eqnarray*} m(\\Xi_c(2939)^0) &=&\n2938.55 \\pm 0.21 \\pm 0.17 \\pm 0.14 ~\\mathrm{ MeV}, \\Gamma(\\Xi_c(2939)^0) &=&\n10.2 \\pm 0.8 \\pm 1.1 ~\\mathrm{ MeV}, \\end{eqnarray*} \\begin{eqnarray*}\nm(\\Xi_c(2965)^0) &=& 2964.88 \\pm 0.26 \\pm 0.14 \\pm 0.14~\\mathrm{ MeV},\n\\Gamma(\\Xi_c(2965)^0) &=& 14.1 \\pm 0.9 \\pm 1.3~\\mathrm{ MeV}, \\end{eqnarray*}\nwhere the uncertainties are statistical, systematic, and due to the limited\nknowledge of the $\\Lambda_c^+$ mass. The $\\Xi_c(2923)^0$ and $\\Xi_c(2939)^0$\nbaryons are new states. The $\\Xi_c(2965)^0$ state is in the vicinity of the\nknown $\\Xi_c(2970)^0$ baryon; however, their masses and natural widths differ\nsignificantly.", "category": "hep-ex" }, { "text": "Measurements of differential cross sections of Z/gamma*+jets+X events in\n proton anti-proton collisions at sqrt{s}=1.96 TeV: We present cross section measurements for Z/gamma*+jets+X production,\ndifferential in the transverse momenta of the three leading jets. The data\nsample was collected with the D0 detector at the Fermilab Tevatron proton\nanti-proton collider at a center-of-mass energy of 1.96 TeV and corresponds to\nan integrated luminosity of 1 fb-1. Leading and next-to-leading order\nperturbative QCD predictions are compared with the measurements, and agreement\nis found within the theoretical and experimental uncertainties. We also make\ncomparisons with the predictions of four event generators. Two\nparton-shower-based generators show significant shape and normalization\ndifferences with respect to the data. In contrast, two generators combining\ntree-level matrix elements with a parton shower give a reasonable description\nof the the shapes observed in data, but the predicted normalizations show\nsignificant differences with respect to the data, reflecting large scale\nuncertainties. For specific choices of scales, the normalizations for either\ngenerator can be made to agree with the measurements.", "category": "hep-ex" }, { "text": "Determination of \u03b1S using OPAL hadronic event shapes at sqrt(s) =\n 91 - 209 GeV and resummed NNLO calculations: Hadronic event shape distributions from e+e- annihilation measured by the\nOPAL experiment at centre-of-mass energies between 91 GeV and 209 GeV are used\nto determine the strong coupling {\\alpha}S. The results are based on QCD\npredictions complete to the next-to- next-to-leading order (NNLO), and on NNLO\ncalculations matched to the resummed next-to-leading-log-approximation terms\n(NNLO+NLLA). The combined NNLO result from all variables and centre-of-mass\nenergies is {\\alpha}S(mZ0) = 0.1201 {\\pm} 0.0008(stat.) {\\pm} 0.0013(exp.)\n{\\pm} 0.0010(had.) {\\pm} 0.0024(theo.). while the combined NNLO+NLLA result is\n{\\alpha}S(mZ0) = 0.1189 {\\pm} 0.0008(stat.) {\\pm} 0.0016(exp.) {\\pm}\n0.0010(had.) {\\pm} 0.0036(theo.). The completeness of the NNLO and NNLO+NLLA\nresults with respect to missing higher order contributions, studied by varying\nthe renormalization scale, is improved compared to previous results based on\nNLO or NLO+NLLA predictions only. The observed energy dependence of {\\alpha}S\nagrees with the QCD prediction of asymptotic freedom and excludes the absence\nof running.", "category": "hep-ex" }, { "text": "X-Ray Multi-Energy Introscopy Systems with New Semiconductor\n Scintillators: Theoretical background and data on the ways of practical realization are\npresented, related to the problem of detection of dangerous organic objects\n(explosives, drugs, etc.) in the presence of other organic substances with\natomic number differing by no more than 20-30%. For this purpose, multi-energy\nX-ray introscopy is used. It has been shown that the \"weakest link\" in the\nexisting multi-energy introscopes used for safety inspection and medicine are\ndetectors of ionizing radiation. In particular, critical is the type of\nscintillator used in the low-energy detection subsystem. Data are presented on\ndesign principles and properties of combined detectors based on a new type of\nsemiconductor scintillators (SCS) -- $ZnSe(Te,O)$, with conversion efficiency\nof 19-22%, afterglow level less then $0.05 %$ after $10 ms$, and radiation\nstability up to $500 Mrad$. Results are given on the practical use of\nexperimental samples of the low-energy detector subsystem based on the new SCS\nmaterial in two-energy introscopes of the 4th and 5th generation.", "category": "hep-ex" }, { "text": "Precision Measurements of the Semileptonic Charm Decays $D^0 \\to \u03c0^-\n \\ell^+ \u03bd$ and $D^0 \\to K^- \\ell^+ \u03bd$: We investigate the decays $D^0\\to\\pi^-\\ell^+\\nu$ and $D^0\\to K^-\\ell^+ \\nu$,\nwhere $\\ell$ is $e$ or $\\mu$, using approximately 7 ${\\rm fb}^{-1}$ of data\ncollected with the CLEO III detector. We find $R_0\\equiv {\\cal B}(D^0\\to\n\\pi^-e^+\\nu)/{\\cal B}(D^0\\to K^-e^+\\nu)= 0.082 \\pm 0.006 \\pm 0.005$. Fits to\nthe kinematic distributions of the data provide parameters describing the form\nfactor of each mode. Combining the form factor results and $R_0$ gives\n$|f^{\\pi}_{+}(0)|^2 |V_{cd}|^2/|f^K_{+}(0)|^2 |V_{cs}|^2 =\n0.038^{+0.006+0.005}_{-0.007-0.003}$.", "category": "hep-ex" }, { "text": "Recent $J/\u03c8$ Results from BESII: The studies on the multi-quark candidates, light scalar mesons and excited\nbaryon states at BES are presented, based on $5.8 \\times 10^7$ $J/\\psi$ data\ncollected with BESII detector. The measurements of some $J/\\psi$ and $\\eta_c$\ndecays are presented too. We also report the searches for the lepton flavor\nviolation and pentaquark states in $J/\\psi$ decays.", "category": "hep-ex" }, { "text": "The Spin Structure Function $g_1^{\\rm p}$ of the Proton and a Test of\n the Bjorken Sum Rule: New results for the double spin asymmetry $A_1^{\\rm p}$ and the proton\nlongitudinal spin structure function $g_1^{\\rm p}$ are presented. They were\nobtained by the COMPASS collaboration using polarised 200 GeV muons scattered\noff a longitudinally polarised NH$_3$ target. The data were collected in 2011\nand complement those recorded in 2007 at 160\\,GeV, in particular at lower\nvalues of $x$. They improve the statistical precision of $g_1^{\\rm p}(x)$ by\nabout a factor of two in the region $x\\lesssim 0.02$. A next-to-leading order\nQCD fit to the $g_1$ world data is performed. It leads to a new determination\nof the quark spin contribution to the nucleon spin, $\\Delta \\Sigma$ ranging\nfrom 0.26 to 0.36, and to a re-evaluation of the first moment of $g_1^{\\rm p}$.\nThe uncertainty of $\\Delta \\Sigma$ is mostly due to the large uncertainty in\nthe present determinations of the gluon helicity distribution. A new evaluation\nof the Bjorken sum rule based on the COMPASS results for the non-singlet\nstructure function $g_1^{\\rm NS}(x,Q^2)$ yields as ratio of the axial and\nvector coupling constants $|g_{\\rm A}/g_{\\rm V}| = 1.22 \\pm 0.05~({\\rm stat.})\n\\pm 0.10~({\\rm syst.})$, which validates the sum rule to an accuracy of about\n9\\%.", "category": "hep-ex" }, { "text": "LHCb time-dependent results: This review reports preliminary results of time-dependent measurements of\ndecays of B^0 mesons and B^0_s mesons coming from the analysis of about 36\npb^-1 of data collected by the LHCb experiment during the 2010 run of the Large\nHadron Collider at sqrt(s)=7 TeV.", "category": "hep-ex" }, { "text": "Potential Constraints to Neutrino-Nucleus Interactions Based on Electron\n Scattering Data: A thorough understanding of neutrino-nucleus interactions physics is crucial\nto achieving precision goals in broader neutrino physics programs. The\ncomplexity of nuclei comprising the detectors and limited understanding of\ntheir weak response constitutes one of the biggest systematic uncertainties in\nneutrino experiments - both at intermediate energies affecting the short- and\nlong-baseline neutrino programs as well as at lower energies affecting coherent\nscattering neutrino programs. While electron and neutrino interactions are\ndifferent at the primary vertex, many underlying relevant physical processes in\nthe nucleus are the same in both cases, and electron scattering data collected\nwith precisely controlled kinematics, large statistics and high precision\nallows one to constrain nuclear properties and specific interaction processes.\nTo this end, electron-nucleus scattering experiments provide vital\ncomplementary information to test, assess and validate different nuclear models\nand event generators intended to be used in neutrino experiments. In fact, for\nmany decades, the study of electron scattering off a nucleus has been used as a\ntool to probe the properties of that nucleus and its electromagnetic response.\nWhile previously existing electron scattering data provide important\ninformation, new and proposed measurements are tied closely to what is required\nfor the neutrino program in terms of expanding kinematic reach, the addition of\nrelevant nuclei and information on the final states hadronic system.", "category": "hep-ex" }, { "text": "Deep Learning for direct Dark Matter search with nuclear emulsions: We propose a new method for the discrimination of sub-micron nuclear recoil\ntracks from an instrumental background in fine-grain nuclear emulsions used in\nthe directional dark matter search. The proposed method uses a 3D Convolutional\nNeural Network, whose parameters are optimised by Bayesian search. Unlike\nprevious studies focused on extracting the directional information, we focus on\nthe signal/background separation exploiting the polarisation dependence of the\nLocalised Surface Plasmon Resonance phenomenon. Comparing the proposed method\nwith the conventional cut-based approach shows a significant boost in the\nreduction factor for given signal efficiency.", "category": "hep-ex" }, { "text": "Charged kaon lifetime at KLOE: Preliminary result on the charged kaon lifetime, obtained by the KLOE\nexperiment operating at DA$\\Phi$NE, the Frascati $\\phi$-factory, is presented", "category": "hep-ex" }, { "text": "Observation of $\u039b_c^+ \\to \u039b^0 K^+$, $\u039b_c^+ \\to\n \u03a3^0 K^+$ and $\u039b_c^+ \\to \u03a3^+ K^+\u03c0^-$ decays: We present measurements of the Cabibbo-suppressed decays $\\Lambda_c^+ \\to\n\\Lambda^0 K^+$ and $\\Lambda_c^+ \\to \\Sigma^0 K^+$ (both first observations),\n$\\Lambda_c^+ \\to \\Sigma^+ K^+\\pi^-$ (seen with large statistics for the first\ntime), $\\Lambda_c^+ \\to p K^+ K^-$ and $\\Lambda_c^+ \\to p \\phi$ (measured with\nimproved accuracy). Improved branching ratio measurements for the decays\n$\\Lambda_c^+ \\to \\Sigma^0 K^+ K^-$ and $\\Lambda_c^+ \\to \\Sigma^0 \\phi$, which\nare attributed to W-exchange diagrams, are shown. We also present the first\nevidence for $\\Lambda_c^+ \\to \\Xi(1690) K^+$ and set an upper limit on\nnon-resonant $\\Lambda_c^+ \\to \\Sigma^0 K^+ K^-$ decay. This analysis was\nperformed using 23.6 fb$^{-1}$ of data collected by the Belle detector at the\n$e^+ e^-$ asymmetric collider KEKB.", "category": "hep-ex" }, { "text": "Observation of medium induced modifications of jet fragmentation in PbPb\n collisions at $\\sqrt{s_\\mathrm{NN}} =$ 5.02 TeV using isolated-photon-tagged\n jets: Measurements of fragmentation functions for jets associated with an isolated\nphoton are presented for the first time in pp and PbPb collisions. The analysis\nuses data collected with the CMS detector at the CERN LHC at a nucleon-nucleon\ncenter-of-mass energy of 5.02 TeV. Fragmentation functions are obtained for\njets with p$_\\mathrm{T}^\\text{jet} >$ 30 GeV in events containing an isolated\nphoton with p$_\\mathrm{T}^\\gamma>$ 60 GeV, using charged tracks with transverse\nmomentum p$_\\mathrm{T}^\\text{trk} >$ 1 GeV in a cone around the jet axis. The\nassociation with an isolated photon constrains the initial p$_\\mathrm{T}$ and\nazimuthal angle of the parton whose shower produced the jet. For central PbPb\ncollisions, modifications of the jet fragmentation functions are observed when\ncompared to those measured in pp collisions, while no significant differences\nare found in the 50% most peripheral collisions. Jets in central PbPb events\nshow an excess (depletion) of low (high) p$_\\mathrm{T}$ particles, with a\ntransition around 3 GeV. This measurement shows for the first time the\nin-medium shower modifications of partons (quark dominated) with well defined\ninitial kinematics. It constitutes a new well-controlled reference for testing\ntheoretical models of the parton passage through the QGP.", "category": "hep-ex" }, { "text": "Observation of the Higgs boson decay to a pair of tau leptons with the\n CMS detector: A measurement of the coupling strength of the Higgs boson to a pair of tau\nleptons is performed using events recorded in proton-proton collisions by the\nCMS experiment at the LHC in 2016 at a center-of-mass energy of 13 TeV. The\ndata set corresponds to an integrated luminosity of 35.9 inverse femtobarns.\nThe H to tau tau signal is established with a significance of 4.9 standard\ndeviations, to be compared to an expected significance of 4.7 standard\ndeviations. The best fit of the product of the observed H to tau tau signal\nproduction cross section and branching fraction is 1.09 +0.27-0.26 times the\nstandard model expectation. The combination with the corresponding measurement\nperformed with data collected by the CMS experiment at center-of-mass energies\nof 7 and 8 TeV leads to an observed significance of 5.9 standard deviations,\nequal to the expected significance. This is the first observation of Higgs\nboson decays to tau leptons by a single experiment.", "category": "hep-ex" }, { "text": "Measurements of underlying-event properties using neutral and charged\n particles in pp collisions at 900 GeV and 7 TeV with the ATLAS detector at\n the LHC: We present first measurements of charged and neutral particle-flow\ncorrelations in pp collisions using the ATLAS calorimeters. Data were collected\nin 2009 and 2010 at centre-of-mass energies of 900 GeV and 7 TeV. Events were\nselected using a minimum-bias trigger which required a charged particle in\nscintillation counters on either side of the interaction point. Particle flows,\nsensitive to the underlying event, are measured using clusters of energy in the\nATLAS calorimeters, taking advantage of their fine granularity. No Monte Carlo\ngenerator used in this analysis can accurately describe the measurements. The\nresults are independent of those based on charged particles measured by the\nATLAS tracking systems and can be used to constrain the parameters of Monte\nCarlo generators.", "category": "hep-ex" }, { "text": "Uncovering the neutrino mass ordering with the next galactic\n core-collapse supernova neutrino burst using water Cherenkov detectors: A major challenge of particle physics is determining the neutrino mass\nordering (MO). Due to matter effects, the flavor content of the neutrino flux\nfrom a Core-Collapse Supernova (CCSN) depends on the true neutrino MO resulting\nin markedly different energy and angle distributions for the measured lepton in\nwater Cherenkov neutrino detectors. In this article, those distributions are\ncompared for eight different CCSN models and used to study how their\ndifferences affect the determination of the neutrino mass ordering. In all\ncases, the inferred neutrino mass ordering is found to be either correct or\ninconclusive, with no significant false positives. However, the substantial\nvariation observed among model predictions emphasizes the criticality of\nongoing research in CCSN modeling.", "category": "hep-ex" }, { "text": "Standard Model Higgs Boson Searches at the Tevatron: The CDF and D{\\O} experiments at the Tevatron are currently the only capable\nof searching for the Standard Model Higgs boson. This article describes their\nmost sensitive searches in the expected Higgs mass range, focusing on advanced\nmethods used to extract the maximal sensitivity from the data. CDF presents\nnewly updated results for $H \\to W^+W^-$ and $ZH \\to l^+l^- b\\bar{b}$. D{\\O}\\\npresents two new searches for $WH \\to l\\nu b\\bar{b}$. These new analyses use\nthe same 1 fb$^{-1}$ dataset as previous searches, but with improved techniques\nresulting in markedly improved sensitivity.", "category": "hep-ex" }, { "text": "First measurement of $\\rm \u03a9_c^0$ production in pp collisions at\n $\\sqrt{s}=13$ TeV with ALICE: Recent measurements of charm-baryon production in proton--proton (pp)\ncollisions at midrapidity by the ALICE collaboration showed that\nbaryon-to-meson yield ratios are significantly higher than those measured in\n$\\rm e^+e^-$ collisions. The charm baryon-to-meson and charm baryon-to-baryon\nyield ratios provide unique information on hadronization mechanisms since the\ncontributions from parton distribution function and parton--parton scattering\nterms cancel in the ratios. In this contribution, the first measurement of $\\rm\n\\Omega_{c}^{0}$ production via the hadronic decay channel $\\rm \\Omega_{c}^{0}\n\\rightarrow \\Omega^{-}\\pi^{+}$ (and its charge conjugate) in $2 J/psi Omega^-, where J/psi ->\nmu^+ mu^-, Omega^- -> Lambda K^-, and Lambda -> p pi^-. Significance of the\nobserved signal is estimated to be 5.5 Gaussian standard deviations. The\nOmega_b mass and lifetime are measured to be 6054.4 +- 6.8 (stat.) +- 0.9\n(syst.) MeV/c^2 and 1.13^{+0.53}_{-0.40}(stat.) +- 0.02(syst.) ps,\nrespectively. In addition, the mass and lifetime of the Xi_b baryon are\nmeasured to be 5790.9 +- 2.6(stat.) +- 0.8(syst.) MeV/c^2 and\n1.56^{+0.27}_{-0.25}(stat.) +- 0.02(syst.) ps, respectively. Under the\nassumption that the Xi_b and Omega_b are produced with similar kinematic\ndistributions as the Lambda_b baryon, we measure\n \\sigma.Br(Xi_b -> J/psi Xi^-)/\\sigma.Br(Lambda_b -> J/Psi Lambda) = 0.167\n^{+0.037}_{-0.025}(stat.) +- 0.012(syst.) and \\sigma.Br(Omega_b -> J/psi\nOmega^-)/\\sigma.Br(Lambda_b -> J/Psi Lambda) = 0.045 ^{+0.017}_{-0.012}(stat.)\n+- 0.004(syst.) for baryons produced with transverse momentum in the range of 6\n- 20 GeV/c.", "category": "hep-ex" }, { "text": "Top cross section measurements at ATLAS: Measurements of the production cross section of top-quark pairs ($t\\bar t$)\nin $pp$ collisions at $\\sqrt{s}$ = 7 TeV are presented using 35 \\ipb\\ of data\nrecorded with the ATLAS detector at the Large Hadron Collider. Events are\nselected in the single lepton (electron or muon) and dilepton topologies with\nmulti-jets, and large missing transverse energy. The result is $\\sigma_{t\\bar\nt} = 180 \\pm 9\\,\\mathrm{(stat.)} \\pm15 \\,\\mathrm{(syst.)} \\pm 6\n\\,\\mathrm{(lumi.)\\,pb}$, which agrees with the Standard Model prediction.", "category": "hep-ex" }, { "text": "Measurement of $CP$ asymmetry in $B_s^0 \\to D_s^{\\mp} K^{\\pm}$ decays: We report the measurements of the $CP$-violating parameters in $B_s^0 \\to\nD_s^{\\mp} K^{\\pm}$ decays observed in $pp$ collisions, using a data set\ncorresponding to an integrated luminosity of $3.0\\,\\text{fb}^{-1}$ recorded\nwith the LHCb detector. We measure $C_f = 0.73 \\pm 0.14 \\pm 0.05$, $A^{\\Delta\n\\Gamma}_f = 0.39 \\pm 0.28 \\pm 0.15$, $A^{\\Delta \\Gamma}_{\\overline{f}} = 0.31\n\\pm 0.28 \\pm 0.15$, $S_f = -0.52 \\pm 0.20 \\pm 0.07$, $S_{\\overline{f}} = -0.49\n\\pm 0.20 \\pm 0.07$, where the uncertainties are statistical and systematic,\nrespectively. These parameters are used together with the world-average value\nof the $B_s^0$ mixing phase, $-2\\beta_s$, to obtain a measurement of the CKM\nangle $\\gamma$ from $B_s^0 \\to D_s^{\\mp} K^{\\pm}$ decays, yielding $\\gamma =\n(128\\,_{-22}^{+17})^\\circ$ modulo $180^\\circ$, where the uncertainty contains\nboth statistical and systematic contributions. This corresponds to\n$3.8\\,\\sigma$ evidence for $CP$ violation in the interference between decay and\ndecay after mixing.", "category": "hep-ex" }, { "text": "Event Shapes and Power Corrections in ep DIS: Deep-inelastic ep scattering data, taken with the H1 detector at HERA, are\nused to study the event shape variables thrust, jet broadening, jet mass, C\nparameter, and two kinds of differential two-jet rates over a large range of\n``relevant energy'' Q between 7 GeV and 100 GeV. The Q dependence of the mean\nvalues is fit to second order calculations of perturbative QCD applying power\nlaw corrections proportional to 1/Q^p to account for hadronization effects. The\nconcept of these power corrections is tested by a systematic investigation in\nterms of a non-perturbative parameter alpha_{p-1} and the strong coupling\nconstant.", "category": "hep-ex" }, { "text": "Physics in the tau-charm Region at BESIII: The Beijing Spectrometer (BESIII) collaboration uses $e^+e^-$ collisions in\nthe tau-charm energy region to study a broad spectrum of topics. These include\nstudies of light mesons and light baryons, studies of charmonium, including\nexotic mesons and baryons containing charmonium, studies of charmed mesons and\nbaryons, studies of QCD and tau physics, as well as searches for new physics.\nThe following is a Snowmass white paper that outlines the BESIII\naccomplishments and potential in each of these areas.", "category": "hep-ex" }, { "text": "Search for pair-produced three-jet resonances in proton-proton\n collisions at $\\sqrt{s} =$ 13 TeV: A search has been performed for pair-produced resonances decaying into three\njets. The proton-proton collision data used for this analysis were collected\nwith the CMS detector in 2016 at a center-of-mass energy of 13 TeV and\ncorrespond to an integrated luminosity of 35.9 fb$^{-1}$. The mass range from\n200 to 2000 GeV is explored in four separate mass regions. The observations\nshow agreement with standard model expectations. The results are interpreted\nwithin the framework of $R$-parity violating SUSY, where pair-produced gluinos\ndecay to a six quark final state. Gluino masses below 1500 GeV are excluded at\n95% confidence level. An analysis based on data with multijet events\nreconstructed at the trigger level extends the reach to masses as low as 200\nGeV. Improved analysis techniques have led to enhanced sensitivity, allowing\nthe most stringent limits to date to be set on gluino pair production.", "category": "hep-ex" }, { "text": "Searching for diboson resonances in the boosted all-hadronic final state\n at $\\sqrt{\\rm{s}}=13$ TeV with CMS: This article summarises three searches for diboson resonances in the\nall-hadronic final state using data collected at a center-of-mass energy of\n$\\sqrt{\\rm{s}}=13$ TeV with the CMS experiment at the CERN LHC. The boson decay\nproducts are contained in one large-radius jet, resulting in dijet final states\nwhich are resolved using jet substructure techniques. The analyses presented\nuse 2.3, 35.9 and 77.3 inverse femtobarns of data collected between 2015 and\n2017. These include the first search for diboson resonances using data\ncollected at a 13 TeV collision energy, the introduction of a new algorithm to\ntag vector bosons in the context of analyzing the data collected in 2016, and\nthe development of a novel multidimensional fit improving on the sensitivity of\nthe previous search method with up to $30\\%$. The results presented here are\nthe most sensitive to date of diboson resonance searches in the dijet final\nstate. An emphasis on improvements in technique for vector boson tagging is\nmade.", "category": "hep-ex" }, { "text": "Experimental Prospects for CP and T Violation Studies in Charm: We present the current status of experimental results and prospects for the\ndetermination of CP and T violation in the charm sector. Such measurements have\nacquired renewed interest in recent years in view of theoretical work, which\nhas highlighted the possibility to probe experimental signatures from New\nPhysics beyond the Standard Model, since the effect of CP violation due to\nStandard Model processes is expected to be highly suppressed in D decays. The\ncurrent limits of experimental sensitivities for these studies are reaching the\ninteresting theoretical regimes. We include new measurements from the Belle,\nBABAR, and CLEO-c collaborations.", "category": "hep-ex" }, { "text": "Electroweak penguin decays at LHCb: Promising ways to search for New Physics effects in radiative penguin decays\nare in the angular analysis of $B_{d} \\rightarrow K^{*0} \\mu^{+}\\mu^{-}$, in\nthe measurement of direct CP violation in $\\B_{d} \\rightarrow\nK^{*0}\\mu^{+}\\mu^{-}$ and a time dependent analysis of $B_{s} \\rightarrow \\phi\n\\gamma$. All of these studies are being pursued at LHCb. First results will be\nshown from the 2010 and early 2011 data, with particular emphasis on $B_{d}\n\\rightarrow K^{*0} \\mu^{+}\\mu^{-}$.", "category": "hep-ex" }, { "text": "Recent results on nucleon resonance electrocouplings from the studies of\n $\u03c0^{+}\u03c0^{-}p$ electroproduction with the CLAS detector: Recent results on nucleon resonance studies in $\\pi^{+}\\pi^{-}p$ electro-\nproduction off protons with the CLAS detector are presented. The analysis of\nCLAS data allowed us to determine all essential contributing mechanisms,\nproviding a credible separation between resonant and non-resonant parts of the\ncross sections in a wide kinematical area of invariant masses of the final\nhadronic system $1.3\u03c0\u03c0, K\u03c0and KK Decays: We report measurements of the branching fractions for $B^0\\to\\pi^+\\pi^-$,\n$K^+\\pi^-$, $K^+K^-$ and $K^0\\pi^0$, and $B^+\\to\\pi^+\\pi^0$, $K^+\\pi^0$,\n$K^0\\pi^+$ and $K^+\\bar{K}{}^0$. The results are based on 10.4 fb$^{-1}$ of\ndata collected on the $\\Upsilon$(4S) resonance at the KEKB $e^+e^-$ storage\nring with the Belle detector, equipped with a high momentum particle\nidentification system for clear separation of charged $\\pi$ and $K$ mesons. We\nfind ${\\cal B}(B^0\\to\\pi^+\\pi^-) =(0.56^{+0.23}_{-0.20}\\pm 0.04)\\times\n10^{-5}$, ${\\cal B}(B^0\\to K^+\\pi^-) =(1.93^{+0.34 +0.15}_{-0.32 -0.06})\\times\n10^{-5}$, ${\\cal B}(B^+\\to K^+\\pi^0) =(1.63^{+0.35 +0.16}_{-0.33 -0.18})\\times\n10^{-5}$, ${\\cal B}(B^+\\to K^0\\pi^+) =(1.37^{+0.57 +0.19}_{-0.48 -0.18})\\times\n10^{-5}$, and ${\\cal B}(B^0\\to K^0\\pi^0) =(1.60^{+0.72 +0.25}_{-0.59\n-0.27})\\times 10^{-5}$, where the first and second errors are statistical and\nsystematic. We also set upper limits of ${\\cal B}(B^+\\to\\pi^+\\pi^0)<1.34\\times\n10^{-5}$, ${\\cal B}(B^0\\to K^+K^-)<0.27\\times 10^{-5}$, and ${\\cal B}(B^+\\to\nK^+\\bar{K}{}^0)<0.50\\times 10^{-5}$ at the 90% confidence level.", "category": "hep-ex" }, { "text": "Measurement of B(Y(nS) -> mu+ mu-) at CLEO: The decay branching fractions of the three narrow Upsilon resonances to mu+\nmu- have been measured by analyzing about 4.3 1/fb e+e- data collected with the\nCLEO III detector. The branching fraction B(Y(1S) -> mu+ mu-) = (2.49 +- 0.02\n+- 0.07)% is consistent with the current world average but B(Y(2S) -> mu+ mu-)\n= (2.03 +- 0.03 +- 0.08)% and B(Y(3S) -> mu+ mu-) = (2.39 +- 0.07 +- 0.10)% are\nsignificantly larger than prior results. These new muonic branching fractions\nimply a narrower total decay width for the Y(2S) and Y(3S) resonances and lower\nother branching fractions that rely on these decays in their determination.", "category": "hep-ex" }, { "text": "Time-dependent CP asymmetries in Bs decays at LHCb: The LHCb experiment will search for New Physics in Bs mixing. The Bs mixing\nphase will be extracted from the measurement of the time-dependent CP asymmetry\nin exclusive Bs decays governed by the b -> ccbar s quark-level transition.\nLarge New Physics effects can be discovered or excluded with the data collected\nduring the very first physics run of LHC. Based on Monte Carlo simulations of\nthe LHCb detector, the expected sensitivity with 2 inverse fb on the\nCP-violation parameter phi_s is sigma(phi_s) = 0.022.", "category": "hep-ex" }, { "text": "Study of Upsilon(3S,2S) -> eta Upsilon(1S) and Upsilon(3S,2S) -> pi+pi-\n Upsilon(1S) hadronic trasitions: We study the Upsilon(3S,2S)->eta Upsilon(1S) and Upsilon(3S,2S)->pi+pi-\nUpsilon(1S) transitions with 122 million Upsilon(3S) and 100 million\nUpsilon(2S) mesons collected by the BaBar detector at the PEP-II asymmetric\nenergy e+e- collider. We measure B[Upsilon(2S)->eta\nUpsilon(1S)]=(2.39+/-0.31(stat.)+/-0.14(syst.))10^-4 and Gamma[Upsilon(2S)->eta\nUpsilon(1S)]/Gamma[Upsilon(2S)-> pi+pi-\nUpsilon(1S)]=(1.35+/-0.17(stat.)+/-0.08(syst.))10^-3. We find no evidence for\nUpsilon(3S)->eta Upsilon(1S) and obtain B[Upsilon(3S)->eta Upsilon(1S)]<1.0\n10^-4 and Gamma[Upsilon(3S)->eta Upsilon(1S)]/Gamma[Upsilon(3S)->pi+pi-\nUpsilon(1S)]<2.3 10^-3 as upper limits at the 90% confidence level. We also\nprovide improved measurements of the Upsilon(2S) - Upsilon(1S) and Upsilon(3S)\n- Upsilon(1S) mass differences, 562.170+/-0.007(stat.)+/-0.088(syst.) MeV/c^2\nand 893.813+/-0.015(stat.)+/-0.107(syst.) MeV/c^2 respectively.", "category": "hep-ex" }, { "text": "Event Structure and Double Helicity Asymmetry in Jet Production from\n Polarized p+p Collisions at sqrt(s) = 200 GeV: We report on event structure and double helicity asymmetry ($A_LL$) of jet\nproduction in longitudinally polarized p+p collisions at $\\sqrt{s}$=200 GeV.\nPhotons and charged particles were measured at midrapidity $|\\eta| < 0.35$ with\nthe requirement of a high-momentum ($>2$ GeV/$c$) photon in each event.\nMeasured event structure is compared with {\\sc pythia} and {\\sc geant}\nsimulations. The shape of jets and the underlying event were well reproduced at\nthis collision energy. For the measurement of jet $A_{LL}$, photons and charged\nparticles were clustered with a seed-cone algorithm to obtain the cluster $p_T$\nsum ($p_T^{\\rm reco}$). The effect of detector response and the underlying\nevents on $p_T^{\\rm reco}$ was evaluated with the simulation. The production\nrate of reconstructed jets is satisfactorily reproduced with the NLO pQCD jet\nproduction cross section. For $4 < p_T^{\\rm reco} < 12$ GeV/$c$ with an average\nbeam polarization of $< P > = 49%$ we measured $A_{LL} = -0.0014 \\pm\n0.0037^{\\rm stat}$ at the lowest $p_T^{\\rm reco}$ bin (4-5 GeV/$c$) and\n$-0.0181 \\pm 0.0282^{\\rm stat}$ at the highest $p_T^{\\rm reco}$ bin (10-12\nGeV/$c$) with a beam polarization scale error of 9.4% and a $\\pT$ scale error\nof 10%. Jets in the measured $p_T^{\\rm reco}$ range arise primarily from\nhard-scattered gluons with momentum fraction $0.02 < x < 0.3$ according to {\\sc\npythia}. The measured $A_{LL}$ is compared with predictions that assume various\n$\\Delta G(x)$ distributions based on the GRSV parameterization. The present\nresult imposes the limit $-1.1 < \\int_{0.02}^{0.3}dx \\Delta G(x, \\mu^2 = 1 {\\rm\nGeV}^2) < 0.4$ at 95% confidence level or $\\int_{0.02}^{0.3}dx \\Delta G(x,\n\\mu^2 = 1 {\\rm GeV}^2) < 0.5$ at 99% confidence level.", "category": "hep-ex" }, { "text": "The Status and Prospects of the Muon $g-2$ Experiment at Fermilab: The E989 Muon $g-2$ Experiment at Fermilab aims to measure the muon magnetic\nanomaly, $a_\\mu$, to an unprecedented precision of 140 parts per billion (ppb),\nrepresenting a four-fold improvement over the current best measurement,\nachieved at Brookhaven National Lab. There stands a greater than 3 standard\ndeviations discrepancy between the Brookhaven measurement of $a_\\mu$ and the\ntheoretical value predicted using the Standard Model. The Fermilab experiment\nseeks to either resolve or confirm this discrepancy, which is suggestive of new\nphysics interactions. To achieve the E989 target precision, the anomalous\nprecession frequency of muons in a magnetic storage ring must be determined\nwith a systematic uncertainty below 70\\,ppb, and the average magnetic field\nexperienced by these stored muons must be known equally well. The muon\nanomalous precession frequency is imprinted on the time-dependent energy\ndistribution of decay positrons observed by 24 electromagnetic calorimeters. A\nsuite of pulsed NMR probes continually monitors the magnetic field. This\ndocument presents the current status of the Fermilab experiment while\nemphasizing the ongoing analysis of the 2018 Run 1 dataset and the systematic\neffects that complicate it.", "category": "hep-ex" }, { "text": "Measurement of Event Shapes in Proton-Antiproton Collisions at\n Center-of-Mass Energy 1.96 TeV: A study of event shape observables in proton-antiproton collisions at 1.96\nTeV is presented. The data for this analysis were recorded by the CDF II\ndetector at the Tevatron collider. The variables studied are the transverse\nthrust and thrust minor, both defined in the plane perpendicular to the beam\ndirection. The observables are measured using energies from unclustered\ncalorimeter cells. In addition to studies of the differential distributions, we\npresent the dependence of event shape mean values on the leading jet transverse\nenergy. Data are compared with pythia Tune A and to resummed parton level\npredictions that were matched to fixed order results at NLO accuracy (NLO+NLL).\nPredictions from pythia Tune A agree fairly well with the data. However, the\nunderlying event contributes significantly to these observables, making it\ndifficult to make direct comparisons to the NLO+NLL predictions, which do not\naccount for the underlying event. To overcome this difficulty, we introduce a\nnew observable, a weighted difference of the mean values of the thrust and\nthrust minor, which is less sensitive to the underlying event, allowing for a\ncomparison with NLO+NLL. Both pythia Tune A and the NLO+NLL calculations agree\nwell within the 20% theoretical uncertainty with the data for this observable,\nindicating that perturbative QCD successfully describes shapes of the hadronic\nfinal states.", "category": "hep-ex" }, { "text": "Hunting for Axionlike Dark Matter by Searching for an Oscillating\n Neutron Electric Dipole Moment: We report on a search for ultra-low-mass axion-like dark matter by analysing\nthe ratio of the spin-precession frequencies of stored ultracold neutrons and\n$^{199}$Hg atoms for an axion-induced oscillating electric dipole moment of the\nneutron and an axion-wind spin-precession effect. No signal consistent with\ndark matter is observed for the axion mass range $10^{-24}~\\textrm{eV} \\le m_a\n\\le 10^{-17}~\\textrm{eV}$. Our null result sets the first laboratory\nconstraints on the coupling of axion dark matter to gluons, which improve on\nastrophysical limits by up to 3 orders of magnitude, and also improves on\nprevious laboratory constraints on the axion coupling to nucleons by up to a\nfactor of 40. The results were initially presented in Phys. Rev. X 7, 041034,\nof which this proceeding is largely a summary.", "category": "hep-ex" }, { "text": "Measurements of the $\u03c4$ Mass and Mass Difference of the $\u03c4^{+}$\n and $\u03c4^{-}$} at BaBar: We present the result from a precision measurement of the mass of the $\\tau$\nlepton, $M_\\tau$, based on $423 fb^{-1}$ of data recorded at the $\\Upsilon(4S)$\nresonance with the BaBar detector. Using a pseudomass endpoint method, we\ndetermine the mass to be $1776.68 \\pm 0.12 (stat) \\pm 0.41 (syst) MeV$. We also\nmeasure the mass difference between the $\\tau^+$ and $\\tau^-$, and obtain\n$(M_{\\tau^{+}}-M_{\\tau^{-}})/M^\\tau_{AVG} = (-3.4 \\pm 1.3 (stat) \\pm 0.3\n(syst)) \\times 10^{-4}$, where $M^\\tau_{AVG}$ is the average value of\n$M_{\\tau^+}$ and $M_{\\tau^-}$.", "category": "hep-ex" }, { "text": "New results on alpha_s and optimized scales: A summary of the latest alpha_s results at LEP1 and LEP2 from event-shape\npredictions at Order(alpha2_s) + NLLA is presented. Later these are compared to\nmeasurements obtained using the Experimentally Optimized Scale method. Finally\nthe alpha_s measurement from the 4-jet rate is discussed.", "category": "hep-ex" }, { "text": "Search for Direct CP Violation in K+-->pi+-pi+pi- Decays by NA48/2: First preliminary measurement of the direct CP-violating parameter Ag by the\nNA48/2 experiment at CERN SPS is presented. Using more than 1.6 billions of\ncharged kaon decays into three charged pions, the charge asymmetry in the\nK+-->pi+-pi+pi- Dalitz plot slope, Ag, has been measured to Ag = (0.5 +- 3.8) x\n10^-4. This result is more than an order of magnitude more precise than results\nof previous experiments.", "category": "hep-ex" }, { "text": "Measurement of the leptonic ttbar charge asymmetry in the dilepton\n channel with the D0 detector: We present the legacy measurement of the leptonic ttbar charge asymmetry in\nthe dilepton channel with the D0 detector.", "category": "hep-ex" }, { "text": "Rare B0_(s) -> mu+mu- decays: This review summarizes the current experimental results on rare B0_(s) ->\nmu+mu- decays of the Tevatron experiments CDF and D0, and the LHC experiments\nATLAS, CMS and LHCb. The experimental branching fraction upper limits for the\nB0_s -> mu+mu- are already quite close to the branching fraction predicted by\nthe Standard Model, and the first observation of the B0_s -> mu+mu- decay is\nexpected soon. The rare decays B0_(s) -> mu+mu- are highly suppressed in the\nStandard Model, and therefore accurate measurements of these branching\nfractions provide complementary constraints to the free parameters of various\nextensions of the Standard Model.", "category": "hep-ex" }, { "text": "A Luminosity Spectrometer for the Zeus Experiment at HERA: The HERA luminosity upgrade is expected to generate two major problems in the\ncurrent method of luminosity determination which is based on counting\nbrehmsstrahlung photons: damage of the calorimeter monitor due to high primary\nsynchrotron radiation and large multiple event (pile-up) corrections. The\nluminosity spectrometer presented in this talk, is a novel method that reduces\nthe impact of these problems in the luminosity measurement and is expected to\nyield a total systematic uncertainty of 1.4%. The spectrometer counts\nbrehmsstrahlung photon conversions in the beam pipe exit window using two small\ncalorimeters (former ZEUS beam pipe calorimeters) symmetrically placed away\nfrom the synchrotron radiation plane. The photon conversion rate is measured by\ncounting electron-positron (ep) coincidences in the calorimeters. The ep\nacceptance is measured using a third calorimeter (6 meter tagger) which tags\nthe brehmsstrahlung electrons. The electron-positron pair is separated by a\nsmall dipole magnet.", "category": "hep-ex" }, { "text": "Limits on Majoron-emitting double-beta decays of Xe-136 in the\n KamLAND-Zen experiment: We present limits on Majoron-emitting neutrinoless double-beta decay modes\nbased on an exposure of 112.3 days with 125 kg of Xe-136. In particular, a\nlower limit on the ordinary (spectral index n = 1) Majoron-emitting decay\nhalf-life of Xe-136 is obtained as T_{1/2}^{0\\nu\\chi^{0}} > 2.6 x 10^{24} yr at\n90% C.L., a factor of five more stringent than previous limits. The\ncorresponding upper limit on the effective Majoron-neutrino coupling, using a\nrange of available nuclear matrix calculations, is < (0.8 - 1.6) x\n10^{-5}. This excludes a previously unconstrained region of parameter space and\nstrongly limits the possible contribution of ordinary Majoron emission modes to\n0\\nu\\beta\\beta decay for neutrino masses in the inverted hierarchy scheme.", "category": "hep-ex" }, { "text": "Searches for the Supersymmetric Partner of the Bottom Quark: We have performed a search for the scalar bottom quark from gluino decays in\nan R-parity conserving SUSY scenario with m(gluino) > m(sbottom), by\ninvestigating a final state of large missing transverse energy, with three or\nmore jets, and some of them from the hadronization of b-quarks. A data sample\nof 156pb-1 collected by the Collider Detector at Fermilab at a center-of-mass\nenergy of 1.96TeV was used. For the final selection, jets containing secondary\ndisplaced vertices were required. This analysis has been performed 'blind', in\nthat the inspection of the signal region was only made after the standard model\nprediction was fina lized. Comparing data with SUSY predictions, we can exclude\nmasses of the gluino and sbottom of up to 280 and 240GeV/c^2 respectively.", "category": "hep-ex" }, { "text": "Measurement of the $B^{\\pm}$ production cross-section in pp collisions\n at $\\sqrt{s} =$ 7 and 13 TeV: The production of $B^{\\pm}$ mesons is studied in $pp$ collisions at\ncentre-of-mass energies of 7 and 13 TeV, using $B^{\\pm}\\rightarrow J/\\psi\nK^{\\pm}$ decays and data samples corresponding to 1.0 fb$^{-1}$ and 0.3\nfb$^{-1}$, respectively. The production cross-sections summed over both charges\nand integrated over the transverse momentum range $0 pi pi pi dynamics through a\nDalitz plot analysis gives the possibility to extract information on the quark\nmass difference. Finally, the branching ratio for the eta --> pi0 gamma gamma\ndecay is compared with previous measurements and with the expectations from\nChiral Perturbation Theory.", "category": "hep-ex" }, { "text": "Study of $K^+ \\rightarrow \u03c0^{0} e^{+} \u03bd\u03b3$ decay with OKA\n setup: Results of a study of the $K^+ \\rightarrow \\pi^{0} e^{+} \\nu \\gamma $ decay\nat OKA setup are presented. More than 32000 events of this decay are observed.\nThe differential spectra over the photon energy and the photon-electron opening\nangle in kaon rest frame are presented. The branching ratios, normalized to\nthat of $K_{e3}$ decay are calculated for different cuts in $E^*_\\gamma$ and\n$cos\\Theta^{*}_{e\\gamma}$. In particular, the branching ratio for\n$E^{*}_{\\gamma}>30$ MeV and $\\Theta^{*}_{e \\gamma}>20^{\\circ}$ is measured R =\n$\\frac{Br(K^+ \\rightarrow \\pi^{0} e^{+} \\nu_{e} \\gamma) } {Br(K^+ \\rightarrow\n\\pi^{0} e^{+} \\nu_{e})} $ =\n=(0.587$\\pm$0.010($stat.$)$\\pm$0.015($syst.$))$\\times10^{-2}$, which is in a\ngood agreement with ChPT $O(p^{4})$ calculations.", "category": "hep-ex" }, { "text": "Measurements of branching fraction ratios and CP asymmetries in B+/-\n ->D_CP K+/- decays in hadron collisions: We reconstruct B+/- -> D K+/- decays in a data sample collected by the CDF II\ndetector at the Tevatron collider corresponding to 1 fb-1 of integrated\nluminosity. We select decay modes where the D meson decays to either K- pi+\n(flavor eigenstate) or K- K+, pi- pi+ (CP-even eigenstates), and measure the\ndirect CP asymmetry A_CP+ = 0.39 +/- 0.17(stat) +/- 0.04(syst), and the double\nratio of CP-even to flavor eigenstate branching fractions R_CP+ = 1.30 +/-\n0.24(stat) +/- 0.12(syst). These measurements will improve the determination of\nthe CKM angle gamma. They are performed here for the first time using data from\nhadron collisions.", "category": "hep-ex" }, { "text": "Search for Dark Matter Annihilation in the Earth using the ANTARES\n Neutrino Telescope: A search for a neutrino signal from WIMP pair annihilations in the centre of\nthe Earth has been performed with the data collected with the ANTARES neutrino\ntelescope from 2007 to 2012. The event selection criteria have been developed\nand tuned to maximise the sensitivity of the experiment to such a neutrino\nsignal. No significant excess of neutrinos over the expected background has\nbeen observed. Upper limits at $90\\%$ C.L. on the WIMP annihilation rate in the\nEarth and the spin independent scattering cross-section of WIMPs to nucleons\n$\\sigma^{SI}_p$ were calculated for WIMP pair annihilations into either\n$\\tau^{+}\\tau^{-}$, $W^+W^-$, $b\\overline{b}$ or the non-SUSY\n$\\nu_{\\mu}\\bar{\\nu}_{\\mu}$ as a function of the WIMP mass (between\n$25\\,\\mathrm{GeV/c^2}$ and $1000\\,\\mathrm{GeV/c^2}$) and as a function of the\nthermally averaged annihilation cross section times velocity $\\langle\\sigma_{A}\nv\\rangle_{Earth}$ of the WIMPs in the centre of the Earth. For masses of the\nWIMP close to the mass of iron nuclei ($50\\,\\mathrm{GeV/c^2}$), the obtained\nlimits on $\\sigma^{SI}_p$ are more stringent than those obtained by other\nindirect searches.", "category": "hep-ex" }, { "text": "Search for charged-lepton flavor violation in top quark production and\n decay in pp collisions at $\\sqrt{s} =$ 13 TeV: Results are presented from a search for charged-lepton flavor violating\n(CLFV) interactions in top quark production and decay in pp collisions at a\ncenter-of-mass energy of 13 TeV. The events are required to contain one\noppositely charged electron-muon pair in the final state, along with at least\none jet identified as originating from a bottom quark. The data correspond to\nan integrated luminosity of 138 fb$^{-1}$, collected by the CMS experiment at\nthe LHC. This analysis includes both the production (q $\\to$ e$\\mu$t) and decay\n(t $\\to$ e$\\mu$q) modes of the top quark through CLFV interactions, with q\nreferring to a u or c quark. These interactions are parametrized using an\neffective field theory approach. With no significant excess over the standard\nmodel expectation, the results are interpreted in terms of vector-, scalar-,\nand tensor-like CLFV four-fermion effective interactions. Finally, observed\nexclusion limits are set at 95% confidence levels on the respective branching\nfractions of a top quark to an e$\\mu$ pair and an up (charm) quark of 0.13\n$\\times$ 10$^{-6}$ (1.31 $\\times$ 10$^{-6}$), 0.07 $\\times$ 10$^{-6}$ (0.89\n$\\times$ 10$^{-6}$), and 0.25 $\\times$ 10$^{-6}$ (2.59 $\\times$ 10$^{-6}$) for\nvector, scalar, and tensor CLFV interactions, respectively.", "category": "hep-ex" }, { "text": "Measurement of the Transverse Single-Spin Asymmetry for Mid-rapidity\n Production of Neutral Pions in Polarized p+p Collisions at 200 GeV\n Center-of-Mass Energy: The spin structure of the proton has revealed itself to be extremely complex\nand is an area of ongoing research. The Relativistic Heavy Ion Collider (RHIC)\nat Brookhaven National Laboratory (BNL) inaugurated its operation as the first\npolarized-proton collider during the 2001-2002 run, marking the beginning of a\nnew era in the study of proton spin structure.\n From the data collected in this run, the PHENIX experiment measured the\ntransverse single-spin asymmetry (A_N) for neutral pion production at x_F~0.0\nover a transverse momentum range of 1 to 5 GeV/c from polarized proton-proton\ninteractions at a center-of-mass energy of 200 GeV and found it to be zero\nwithin a few percent. Interest in these measurements arises from the\nobservation of large (~30%) transverse single-spin asymmetries in pion\nproduction at forward angles by the E704 collaboration at Fermilab (sqrt{s} =\n19.4 GeV), found by the STAR and BRAHMS experiments to persist at RHIC\nenergies, as well as single-spin, azimuthal asymmetries observed recently in\nsemi-inclusive deep-inelastic scattering experiments. Such large asymmetries\nwere initially surprising because at leading order, pQCD predicted only small\neffects.\n Several possible origins of these large asymmetries have been proposed.\nDespite great theoretical progress in recent years, no single, clear formalism\nhas emerged in which to interpret the available data. Further theoretical work\nand a variety of additional experimental measurements will be necessary to\nunderstand current results and elucidate the transverse spin structure of the\nproton.", "category": "hep-ex" }, { "text": "Search for Cosmic-ray Boosted Sub-GeV Dark Matter using Recoil Protons\n at Super-Kamiokande: We report a search for cosmic-ray boosted dark matter with protons using the\n0.37 megaton$\\times$years data collected at Super-Kamiokande experiment during\nthe 1996-2018 period (SKI-IV phase). We searched for an excess of proton\nrecoils above the atmospheric neutrino background from the vicinity of the\nGalactic Center. No such excess is observed, and limits are calculated for two\nreference models of dark matter with either a constant interaction\ncross-section or through a scalar mediator. This is the first experimental\nsearch for boosted dark matter with hadrons using directional information. The\nresults present the most stringent limits on cosmic-ray boosted dark matter and\nexclude the dark matter-nucleon elastic scattering cross-section between\n$10^{-33}\\text{ cm}^{2}$ and $10^{-27}\\text{ cm}^{2}$ for dark matter mass from\n10 MeV/$c^2$ to 1 GeV/$c^2$.", "category": "hep-ex" }, { "text": "Correlated inclusive /\\bar production in e+e- annihilations at\n sqrt(s)~10.5 GeV: Using a 13.7/fb sample of continuum two-jet e+e- -> qqbar events collected\nwith the CLEO detector, we have searched for correlations between / and /\\bar\nparticles, specifically in cases where the opening angle between the two\nparticles is large and each has momentum $>$1 GeV/c. Such correlations may\nindicate the presence of baryon number conservation at the primary quark level.\nA previous CLEO study of /\\c/\\cbar correlations indicated direct, associated\nproduction of primary charmed baryons /\\c: e+e- -> ccbar -> /\\c/\\cbar. That\neffect was not observed in Monte Carlo simulations. Our current search for\nsimilar direct, associated production of / baryons at the primary quark level\n(e+e- -> ssbar -> /\\bar, e.g.) qualitatively indicates a similar effect,\nalthough it relies on a Monte Carlo dependent subtraction of background /\\bar\nproduction (based on the default JETSET 7.4 event generator).", "category": "hep-ex" }, { "text": "Feasibility, engineering aspects and physics reach of microwave cavity\n experiments searching for hidden photons and axions: Using microwave cavities one can build a resonant\n``light-shining-through-walls'' experiment to search for hidden sector photons\nand axion like particles, predicted in many extensions of the standard model.\nIn this note we make a feasibility study of the sensitivities which can be\nreached using state of the art technology.", "category": "hep-ex" }, { "text": "Performance of the CMS Zero Degree Calorimeters in pPb collisions at the\n LHC: The two Zero Degree Calorimeters (ZDCs) of the CMS experiment are located at\n$\\pm 140~$m from the collision point and detect neutral particles in the\n$|\\eta| > 8.3$ pseudorapidity region. This paper presents a study on the\nperformance of the ZDC in the 2016 pPb run. The response of the detectors to\nultrarelativistic neutrons is studied using in-depth Monte Carlo simulations. A\nmethod of signal extraction based on template fits is presented, along with a\ndedicated calibration procedure. A deconvolution technique for the correction\nof overlapping collision events is discussed.", "category": "hep-ex" }, { "text": "Recent Results from the Tevatron Fixed Target and Collider Experiments: We present a review of recent QCD related results from the Fermilab Tevatron\nfixed target and collider experiments. Topics include jet and boson production,\nW boson and top quark mass measurements, and studies of CP violation.", "category": "hep-ex" }, { "text": "Study of charmless hadronic B decays into the final states $K\u03c0,\n \u03c0\u03c0$, and KK, with the first observation of $B \\to \u03c0^+ \u03c0^-$ and $B\\to\n K^0\u03c0^0$: We have studied charmless hadronic decays of B mesons into two-body final\nstates with kaons and pions. We present preliminary results based on 9.66\nmillion $B\\bar{B}$ pairs collected with the CLEO detector. We have made the\nfirst observation of the decay $B \\to \\pi^+\\pi^-$, with the branching fraction\nof $Br(B \\to \\pi^+ \\pi^-) = (4.7^{+1.8}_{-1.5} \\pm 0.6) \\times 10^{-6}$. We\nhave also observed for the first time the decay $B \\to K^0\\pi^0$ with the\nbranching fraction of $Br(B \\to K^0 \\pi^0) = (14.8^{+5.9+2.4}_{-5.1-3.3})\n\\times 10^{-6}$, thus completing the set of four $K\\pi$ branching fraction\nmeasurements. We present improved measurements for the decays $B\\to\nK^{\\pm}\\pi^{\\mp}$, $B^{\\pm}\\to K^0\\pi^{\\pm}$, and $B^{\\pm}\\to K^{\\pm}\\pi^0$. We\nuse these and other charmless hadronic B decays to make a first determination\nof the value of the weak phase ${\\rm Arg}(V^*_{ub})=\\gamma =\n{113^\\circ}^{+25^\\circ}_{-23^\\circ}$.", "category": "hep-ex" }, { "text": "Top properties (excluding mass) and ancillary measurements: A review on recent top quark properties measurements by the ATLAS and CMS\nCollaborations in pp collisions at the LHC is presented.", "category": "hep-ex" }, { "text": "Search for Dark Matter at CMS: The results are presented from searches with the CMS experiment for\ndirectly-produced dark matter particles. All these searches use the full LHC\nRun-I dataset of ~20/fb of proton-proton collisions at 8TeV centre-of-mass\nenergy. Final states with a monojet, monophoton, and monolepton signature are\nconsidered, as well as processes with dark-matter particles produced in\nassociation with top quarks. Most of these results have been interpreted using\nan effective field theory approach, while first results are also reported with\nsimplified models.", "category": "hep-ex" }, { "text": "Interpretation of Scalar and axial mesons in LHCb from an historical\n perspective: LHCb measurements of $B_{d,s} \\to J/\\psi + X$ are shown to be consistent with\nhistorical data on scalar and axial mesons below 2 GeV. This is in contrast to\nsome recent interpretations of these data. Further tests of our hypotheses in\nother $B_{u,d,s} \\to J/\\psi + X$ decay modes are suggested.", "category": "hep-ex" }, { "text": "Search for supersymmetric particles in events with lepton pairs and\n large missing transverse momentum in sqrt{s} = 7 TeV proton-proton collisions\n with the ATLAS experiment: Results are presented of searches for the production of supersymmetric\nparticles decaying into final states with missing transverse momentum and\nexactly two isolated leptons in sqrt{s}=7 TeV proton-proton collisions at the\nLarge Hadron Collider. Search strategies requiring lepton pairs with identical\nsign or opposite sign electric charges are described. In a data sample\ncorresponding to an integrated luminosity of 35 pb-1 collected with the ATLAS\ndetector, no significant excesses are observed. Based on specific benchmark\nmodels, limits are placed on the squark mass between 450 and 690 GeV for\nsquarks approximately degenerate in mass with gluinos, depending on the\nsupersymmetric mass hierarchy considered.", "category": "hep-ex" }, { "text": "Investigation of the $e^+e^- \\to \u03c9\u03c0^0 \\to \u03c0^0 \u03c0^0 \u03b3$\n reaction in the energy domain near the $\u03c6$-meson: The $e^+e^- \\to \\omega \\pi^0 \\to \\pi^0 \\pi^0 \\gamma$ process was investigated\nin the SND experiment at the VEPP-2M collider. A narrow energy interval near\nthe $\\phi$-meson was scanned. The observed cross-section reveals, at the level\nof three standard deviation, the interference effect caused by $\\phi \\to\n\\pi^0\\pi^0\\gamma$ decay. The cross-section parameters, as well as the real and\nimaginary parts of the $\\phi$-meson related amplitude, were measured.", "category": "hep-ex" }, { "text": "Measurements of top-quark pair differential cross-sections in the $e\u03bc$\n channel in $pp$ collisions at $\\sqrt{s} = 13$ TeV using the ATLAS detector: This article presents measurements of $t\\bar{t}$ differential cross-sections\nin a fiducial phase-space region, using an integrated luminosity of 3.2\nfb$^{-1}$ of proton--proton data at a centre-of-mass energy of $\\sqrt{s} = 13$\nTeV recorded by the ATLAS experiment at the LHC in 2015. Differential\ncross-sections are measured as a function of the transverse momentum and\nabsolute rapidity of the top quark, and of the transverse momentum, absolute\nrapidity and invariant mass of the $t\\bar{t}$ system. The $t\\bar{t}$ events are\nselected by requiring one electron and one muon of opposite electric charge,\nand at least two jets, one of which must be tagged as containing a $b$-hadron.\nThe measured differential cross-sections are compared to predictions of\nnext-to-leading order generators matched to parton showers and the measurements\nare found to be consistent with all models within the experimental\nuncertainties with the exception of the POWHEG-Box + HERWIG++ predictions,\nwhich differ significantly from the data in both the transverse momentum of the\ntop quark and the mass of the $t\\bar{t}$ system.", "category": "hep-ex" }, { "text": "Inclusive and exclusive measurements of $B$ decays to $\u03c7_{c1}$ and\n $\u03c7_{c2}$ at Belle: We report inclusive and exclusive measurements for $\\chi_{c1}$ and\n$\\chi_{c2}$ production in $B$ decays. We measure $\\mathcal{B}(B \\to \\chi_{c1}\nX)$= $(3.03 \\pm 0.05(\\mbox{stat}) \\pm 0.24(\\mbox{syst})) \\times 10^{-3}$ and\n$\\mathcal{B}(B \\to \\chi_{c2} X)$= $(0.70 \\pm 0.06(\\mbox{stat}) \\pm\n0.10(\\mbox{syst})) \\times 10^{-3}$. For the first time, $\\chi_{c2}$ production\nin exclusive $B$ decays in the modes $B^0 \\to \\chi_{c2}\\pi^- K^+$ and $B^+ \\to\n\\chi_{c2} \\pi^+ \\pi^- K^+$ has been observed, along with first evidence for the\n$B^+ \\to \\chi_{c2} \\pi^+ K_S^0$ decay mode. For $\\chi_{c1}$ production, we\nreport the first observation in the $B^+ \\to \\chi_{c1} \\pi^+ \\pi^- K^+$, $B^0\n\\to \\chi_{c1} \\pi^+ \\pi^- K_S^0$ and $B^0 \\to \\chi_{c1} \\pi^0 \\pi^- K^+$ decay\nmodes. Using these decay modes, we observe a difference in the production\nmechanism of $\\chi_{c2}$ in comparison to $\\chi_{c1}$ in $B$ decays. In\naddition, we report searches for $X(3872)$ and $\\chi_{c1}(2P)$ in the $B^+ \\to\n(\\chi_{c1} \\pi^+ \\pi^-) K^+$ decay mode. The reported results use $772 \\times\n10^{6}$ $B\\overline{B}$ events collected at the $\\Upsilon(4S)$ resonance with\nthe Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider.", "category": "hep-ex" }, { "text": "Forward pi^0-meson production at HERA: The production of high transverse momentum piz^0-mesons has been measured in\ndeep-inelastic e-p scattering events at low Bjorken-$x$ taken with the\n H1 detector at HERA. The production of high p_T particles is strongly\ncorrelated to the emission of hard partons in QCD and is therefore sensitive to\nthe dynamics of the strong interaction. For the first time the measurement of\nsingle particles has been extended to the region of small angles w.r.t. the\nproton remnant (forward region) and down to very low values of x ~ 5x10^-5.\nThis region is expected to be particularly sensitive to QCD evolution effects\nin final states. Differential cross sections of inclusive pi^0-meson production\nhave been measured as a function of Bjorken-x and the four-momentum transfer\nQ^2, and also as a function of the transverse momentum and the polar angle of\nthe pi^0-mesons. A recent BFKL calculation and QCD models based on the DGLAP\nsplitting functions are compared to the data. The best description of the data\nis achieved by the BFKL calculation.", "category": "hep-ex" }, { "text": "Recent Results on $\u03c8(3770)$ Physics at BES-II: About 33, 6.5 and 1.0 pb$^{-1}$ of $e^+e^-$ annihilation data were,\nrespectively, taken around the center-of-mass energies of $\\sqrt s=$ 3.773 GeV,\nat $\\sqrt s=$ 3.650 GeV and at $\\sqrt s=$ 3.6648 GeV with the BES-II detector\nat the BEPC collider. By analyzing these data sets, we measure the branching\nfraction for $\\psi(3770)\\to$ non-$D\\bar D$; observe an anomalous line shape of\nthe cross section for $e^+e^-\\to$ hadrons in the energy region from 3.650 to\n3.872 GeV; and measure the line shapes of the $D^+D^-$, $D^0\\bar D^0$ and\n$D\\bar D$ production and the ratios of the production rates of $D^+D^-$ and\n$D^0\\bar D^0$ in $e^+e^-$ annihilation at $\\psi(3770)$ resonance. We also\nsearch for $\\psi(3770)$ decay into exclusive light hadron processes containing\n$K^0_S$ or $\\pi^0\\pi^0$ mesons in the final states.", "category": "hep-ex" }, { "text": "Measurement of the top quark pair production cross-section with ATLAS in\n the single lepton channel: A measurement of the production cross-section for top quark pairs (t tbar) in\npp collisions at sqrt{s} = 7 TeV is presented using data recorded with the\nATLAS detector at the Large Hadron Collider. Events are selected in the single\nlepton topology by requiring an electron or muon, large missing transverse\nmomentum and at least three jets. With a data sample of 35/pb, two different\nmultivariate methods, one of which uses b-quark jet identification while the\nother does not, use kinematic variables to obtain cross-section measurements of\nsigma (t tbar) = 187 +/- 11 (stat.) +18-17 (syst.) +/- 6 (lumi.) pb and sigma\n(t tbar) = 173 +/- 17 (stat.) +18-16 (syst.) +/- 6 (lumi.) pb} respectively.\nThe two measurements are in agreement with each other and with QCD\ncalculations. The first measurement has a better a priori sensitivity and\nconstitutes the main result of this Letter.", "category": "hep-ex" }, { "text": "Measurement of Mw from LEP2: In 1997 each LEP experiment collected approximately 55 inv. pb of data at a\ncenter-of-mass energy of 183 GeV. These data yield a sample of candidate e+e-\n-> WW events from which the mass of the W boson, Mw, is measured. The LEP\ncombined result, including data taken at roots = 161 and 172 GeV and assuming\nthe Standard Model relation between the W decay width and mass, is\n Mw = 80.35 +/- 0.07 (exp) +/- 0.04 (CR) +/- 0.03 (E_beam) GeV, where the\nerrors correspond to experimental, colour-reconnection/Bose-Einstein, and LEP\nbeam energy uncertainties respectively.", "category": "hep-ex" }, { "text": "The search for solar axions in the CAST experiment: The CAST (CERN Axion Solar Telescope) experiment at CERN searches for solar\naxions with energies in the keV range. It is possible that axions are produced\nin the core of the sun by the interaction of thermal photons with virtual\nphotons of strong electromagnetic fields. In this experiment, the solar axions\ncan be reconverted to photons in the transversal field of a 9 Tesla\nsuperconducting magnet. At both ends of the 10m-long dipole magnet three\ndifferent X-ray detectors were installed, which are sensitive in the\ninteresting photon energy range. Preliminary results from the analysis of the\n2004 data are presented: g$_{a\\gamma}<0.9\\times10^{-10}$ GeV$^{-1}$ at 95% C.L.\nfor axion masses m$_{a} <$ 0.02 eV. At the end of 2005, data started to be\ntaken with a buffer gas in the magnet pipes in order to extend the sensitivity\nto axion masses up to 0.8 eV.", "category": "hep-ex" }, { "text": "Measurement of inclusive jet and dijet cross sections in proton-proton\n collisions at 7 TeV centre-of-mass energy with the ATLAS detector: Jet cross sections have been measured for the first time in proton-proton\ncollisions at a centre-of-mass energy of 7 TeV using the ATLAS detector. The\nmeasurement uses an integrated luminosity of 17 nb-1 recorded at the Large\nHadron Collider. The anti-kt algorithm is used to identify jets, with two jet\nresolution parameters, R = 0.4 and 0.6. The dominant uncertainty comes from the\njet energy scale, which is determined to within 7% for central jets above 60\nGeV transverse momentum. Inclusive single-jet differential cross sections are\npresented as functions of jet transverse momentum and rapidity. Dijet cross\nsections are presented as functions of dijet mass and the angular variable\n$\\chi$. The results are compared to expectations based on next-to-leading-order\nQCD, which agree with the data, providing a validation of the theory in a new\nkinematic regime.", "category": "hep-ex" }, { "text": "High Energy Muon Momentum Estimation from Multiple Coulomb Scattering in\n Dense Detectors: A method is described for estimating muon track momentum from the\ndistribution of hits along tracks in dense calorimeters due to multiple Coulomb\nscattering (MCS). The method requires only well-aligned conventional drift\nchambers or similar tracking devices and can be implemented with or without a\nmagnetic field present. Neutrino experiments can use this technique to increase\nacceptance for large angle charged-current scattering events. Resolutions in a\ntypical detector geometry vary from ~10% at p=20 GeV/c to ~50% for p=500 GeV/c,\nif the number of hits on the track is sufficient.", "category": "hep-ex" }, { "text": "Extraction of F_2^c(x,Q^2) from D* cross sections at H1: The charm contribution to the proton structure, F_2^c(x,Q^2), is determined\nusing the inclusive cross sections of D*(2010) meson production in\ndeep-inelastic scattering. The cross section measurement covers the region 5 <\nQ2 < 1000 GeV2 in photon virtuality and 0.02 < y < 0.70 in the inelasticity of\nthe scattering process. The D* meson is measured in transverse momentum and\npseudo-rapidity down to p_T > 1.5 GeV and up to |eta| < 1.5. The data were\ntaken with the H1 detector corresponding to an integrated luminosity of 347\npb-1. F_2^c is determined from the D* production cross sections and compared to\nleading and next-to-leading order perturbative QCD predictions.", "category": "hep-ex" }, { "text": "The experimental future of Neutrino Oscillations: After the recent experimental results on neutrino oscillations, some shape\nstarts to emerge from the puzzle. However, the situation is still far from\nbeing clarified. First of all, accommodating all experimental results in a\nsingle and simple framework is not possible, and the possibility of sterile\nneutrinos entering the oscillation process has not been ruled out. Moreover,\nnew questions arise that the presently-available data, nor those that will be\navailable in a near future, will be able to answer. In this paper some of these\nproblems will be discussed, as well as the experimental guidelines for their\nclarification.", "category": "hep-ex" }, { "text": "The program of research at hadronic beams of ITEP accelerator.\n (Collection of experimental proposals): This is a collection of proposals of experiments at hadronic beams of 10 GeV\naccelerator, situated at the Institute of Theoretical and Experimental Physics\n(Moscow, Russia). The proposals were presented by the leaders of several ITEP\nexperimental groups and include selected problems of hadron-hadron (exotic\nstates, scalar mesons, electomagnetic form factors, polarization phenomena\netc.) and hadron-nucleon interactions (flucton and nuclear matter properties,\nhadron properties inside nuclei, interactions at small distances). Most of\nproposals are united by an idea of a common magnetic spectrometer with LiH(D)\nand polarized targets, wich could be built on the base of an existing 3m\nmagnet. Some of them also refer to the intrinsic accelerator beam and to the\nnew ion ring.", "category": "hep-ex" }, { "text": "Direct determination of Neutrino Mass from Tritium Beta Spectrum: The investigation of the endpoint region of the tritium beta decay spectrum\nis still the most sensitive direct method to determine the neutrino mass scale.\nIn the nineties and the beginning of this century the tritium beta decay\nexperiments at Mainz and Troitsk have reached a sensitivity on the neutrino\nmass of 2 eV/c^2 . They were using a new type of high-resolution spectrometer\nwith large sensitivity, the MAC-E-Filter, and were studying the systematics in\ndetail. Currently, the KATRIN experiment is being set up at Forschungszentrum\nKarlsruhe, Germany. KATRIN will improve the neutrino mass sensitivity by one\norder of magnitude down to 0.2 eV/c^2, sufficient to cover the degenerate\nneutrino mass scenarios and the cosmologically relevant neutrino mass range.", "category": "hep-ex" }, { "text": "An Experimentalist's View of Neutrino Oscillations: Neutrinos, and primarily neutrino oscillations, have undoubtedly been one of\nthe most exciting topics in the field of high-energy physics over the past few\nyears. The existence of neutrino oscillations would require an extension of the\ncurrently accepted description of sub-nuclear phenomena beyond the Standard\nModel. Compelling evidence of new physics, which seems to be pointing towards\nneutrino oscillations, is coming from the solar neutrino deficit and from the\natmospheric neutrino anomaly. More controversial effects have been observed\nwith artificially produced neutrinos. The present experimental status of\nneutrino oscillations is reviewed, as well as the planned future experimental\nprogramme, which, it is hoped, will solve most of the outstanding puzzles.", "category": "hep-ex" }, { "text": "Discovery of Single Top Quark Production: The first observation of electroweak single top quark production was recently\nreported by the the D0 and CDF collaborations based on 2.3 and 3.2 fb-1 of\nppbar collision data collected at \\sqrt{s}=1.96 TeV from the Fermilab Tevatron\ncollider. Several multivariate techniques are used to separate the single top\nsignal from backgrounds, and both collaborations present measurements of the\nsingle top cross section and the CKM matrix element |Vtb|.", "category": "hep-ex" }, { "text": "Search for $CP$ violation with kinematic asymmetries in the $D^0 \\to K^+\n K^- \u03c0^+ \u03c0^-$ decay: We search for $CP$ violation in the singly-Cabibbo-suppressed decay\n$D^{0}\\rightarrow K^{+}K^{-}\\pi^{+}\\pi^{-}$ using data corresponding to an\nintegrated luminosity of $988\\text{ }{\\rm fb}^{-1}$ collected by the Belle\ndetector at the KEKB $e^{+}e^{-}$ collider. We measure a set of five\nkinematically dependent $CP$ asymmetries, of which four asymmetries are\nmeasured for the first time. The set of asymmetry measurements can be sensitive\nto $CP$ violation via interference between the different partial-wave\ncontributions to the decay and performed on other pseudoscalar decays. We find\nno evidence of $CP$ violation.", "category": "hep-ex" }, { "text": "Search for high-mass Z-gamma resonances in e+e-gamma and mu+mu-gamma\n final states in proton-proton collisions at sqrt(s) = 8 and 13 TeV: This paper describes the search for a high-mass narrow-width scalar particle\ndecaying into a Z boson and a photon. The analysis is performed using\nproton-proton collision data recorded with the CMS detector at the LHC at\ncenter-of-mass energies of 8 and 13 TeV, corresponding to integrated\nluminosities of 19.7 and 2.7 inverse femtobarns, respectively. The Z bosons are\nreconstructed from opposite-sign electron or muon pairs. No statistically\nsignificant deviation from the standard model predictions has been found in the\n200-2000 GeV mass range. Upper limits at 95% confidence level have been derived\non the product of the scalar particle production cross section and the\nbranching fraction of the Z decaying into electrons or muons, which range from\n280 to 20 fb for resonance masses between 200 and 2000 GeV.", "category": "hep-ex" }, { "text": "Proton structure and elastic scattering amplitudes: Three main statements are advocated in this talk:\n 1. Protons become more active at the periphery with increase of their\ncollision energy as follows from comparison of ISR and LHC data.\n 2. The geometric scaling is violated even in the diffraction region as\nfollows from comparison of lower energy and LHC data.\n 3. The problem of the ratio of real to imaginary parts of the elastic\nscattering amplitude at non-zero transferred momenta is very crucial.\n The talk is based on arXiv:1206.5474 (review), 1202.2016, 1204.1914,\n1204.4866, 1208.3073, 1209.1935, 1212.3313, 1304.5345, 1306.5384. All papers\nhave been published already.", "category": "hep-ex" }, { "text": "The LHCb ultra-fast simulation option, Lamarr: design and validation: Detailed detector simulation is the major consumer of CPU resources at LHCb,\nhaving used more than 90% of the total computing budget during Run 2 of the\nLarge Hadron Collider at CERN. As data is collected by the upgraded LHCb\ndetector during Run 3 of the LHC, larger requests for simulated data samples\nare necessary, and will far exceed the pledged resources of the experiment,\neven with existing fast simulation options. An evolution of technologies and\ntechniques to produce simulated samples is mandatory to meet the upcoming needs\nof analysis to interpret signal versus background and measure efficiencies. In\nthis context, we propose Lamarr, a Gaudi-based framework designed to offer the\nfastest solution for the simulation of the LHCb detector. Lamarr consists of a\npipeline of modules parameterizing both the detector response and the\nreconstruction algorithms of the LHCb experiment. Most of the parameterizations\nare made of Deep Generative Models and Gradient Boosted Decision Trees trained\non simulated samples or alternatively, where possible, on real data. Embedding\nLamarr in the general LHCb Gauss Simulation framework allows combining its\nexecution with any of the available generators in a seamless way. Lamarr has\nbeen validated by comparing key reconstructed quantities with Detailed\nSimulation. Good agreement of the simulated distributions is obtained with\ntwo-order-of-magnitude speed-up of the simulation phase.", "category": "hep-ex" }, { "text": "First study of the CP-violating phase and decay-width difference in\n $B_s^0\\to\u03c8(2S)\u03c6$ decays: A time-dependent angular analysis of $B_s^0\\to\\psi(2S)\\phi$ decays is\nperformed using data recorded by the LHCb experiment. The data set corresponds\nto an integrated luminosity of 3.0\\invfb collected during Run 1 of the LHC. The\nCP-violating phase and decay-width difference of the $B_s^0$ system are\nmeasured to be $\\phi_s = 0.23^{+0.29}_{-0.28} \\pm 0.02$ rad and $\\Delta\\Gamma_s\n= 0.066^{+0.041}_{-0.044} \\pm 0.007$ ps$^{-1}$, respectively, where the first\nuncertainty is statistical and the second systematic. This is the first time\nthat $\\phi_s$ and $\\Delta\\Gamma_s$ have been measured in a decay containing the\n$\\psi(2S)$ resonance.", "category": "hep-ex" }, { "text": "Measurement of Baryon Electromagnetic Form Factors at BESIII: The Beijing $e^+e^-$-collider (BEPCII) is a double-ring symmetric collider\nrunning at center-of-mass energies between 2.0 and 4.6 GeV. This energy range\nallows the BESIII-experiment to measure baryon electromagnetic form factors in\ndirect $e^+e^-$-annihilation and in initial state radiation processes. In this\npaper, results on $e^+e^-\\rightarrow p\\bar{p}$ and $e^+e^-\\rightarrow \\Lambda\n\\bar{\\Lambda}$ based on data collected by BESIII in 2011 and 2012 are\npresented. Expectations from the BESIII high luminosity energy scan from 2015\nand from radiative return at different center-of-mass energies are also\nreported.", "category": "hep-ex" }, { "text": "First measurement of low intensity fast neutron background from rock at\n the Boulby Underground Laboratory: A technique to measure low intensity fast neutron flux has been developed.\nThe design, calibrations, procedure for data analysis and interpretation of the\nresults are discussed in detail. The technique has been applied to measure the\nneutron background from rock at the Boulby Underground Laboratory, a site used\nfor dark matter and other experiments, requiring shielding from cosmic ray\nmuons. The experiment was performed using a liquid scintillation detector. A\n6.1 litre volume stainless steel cell was filled with an in-house made liquid\nscintillator loaded with Gd to enhance neutron capture. A two-pulse signature\n(proton recoils followed by gammas from neutron capture) was used to identify\nthe neutron events from much larger gamma background from PMTs. Suppression of\ngammas from the rock was achieved by surrounding the detector with high-purity\nlead and copper. Calibrations of the detector were performed with various gamma\nand neutron sources. Special care was taken to eliminate PMT afterpulses and\ncorrelated background events from the delayed coincidences of two pulses in the\nBi-Po decay chain. A four month run revealed a neutron-induced event rate of\n1.84 +- 0.65 (stat.) events/day. Monte Carlo simulations based on the GEANT4\ntoolkit were carried out to estimate the efficiency of the detector and the\nenergy spectra of the expected proton recoils. From comparison of the measured\nrate with Monte Carlo simulations the flux of fast neutrons from rock was\nestimated as (1.72 +- 0.61 (stat.) +- 0.38 (syst.))*10^(-6) cm^(-2) s^(-1)\nabove 0.5 MeV.", "category": "hep-ex" }, { "text": "Differential Z + jet cross section measurements at 8 TeV: The measurement of differential cross section of a Z boson produced in\nassociation with jets is presented. The cross section is presented with respect\nto various jet kinematic variables where the Z bosons are reconstructed from\nopposite sign lepton pairs. The analysis is based on data of proton proton\ncollisions with the centre of mass energy of 8 TeV collected in 2012 by the CMS\nexperiment at LHC corresponding to 19.8 /fb of integrated luminosity. Obtained\nresults are compared with different generators and are shown to be consistent\nwith the Standard Model predictions.", "category": "hep-ex" }, { "text": "Measurements of the mass and width of the eta_c using psi' -> gamma\n eta_c: The mass and width of the lowest lying S-wave spin singlet charmonium state,\nthe eta_c, are measured using a data sample of 1.06x10^8 psi' decays collected\nwith the BESIII detector at the BEPCII storage ring. We use a model that\nincorporates interference between the signal reaction, psi' -> gamma eta_c, and\na non-resonant radiative background to successfully describe the line shape of\nthe eta_c. We measure the eta_c mass to be 2984.3 +- 0.6 +- 0.6 MeV/c^2 and the\ntotal width to be 32.0 +- 1.2 +- 1.0 MeV, where the first errors are\nstatistical and the second are systematic.", "category": "hep-ex" }, { "text": "Searches for leptoquarks and excited fermions at HERA: Recent results on searches for new particles at the electron-proton collider\nHERA are reported. Based on roughly 100pb-1 of e^+p data and 16pb-1 of e^-p\ndata per experiment, taken in the years 1994-2000, the H1 and ZEUS\ncollaborations have derived new exclusion limits for the direct production of\nexcited fermion states and leptoquarks. The latter are searched for in\ndifferent decay channels, including lepton-flavor violating decays. The\nproduction of R_P-violating squarks followed by leptoquark-like decays to\nlepton and quark is studied, as are cascade decays yielding multi-jet plus\nlepton signatures. New limits from indirect searches are also reported. Several\nof the searches obtain sensitivities of the same order or exceeding those of\nother experiments, indicating the substantial discovery potential of future\nHERA running.", "category": "hep-ex" }, { "text": "Measurement of Branching Fractions for $B\\to \u03b7_c K^{(*)}$ Decays: We report measurements of branching fractions for charged and neutral $B\\to\n\\eta_c K$ decays where the $\\eta_c$ meson is reconstructed in the $K_S^0\nK^{\\pm}\\pi^{\\mp}, K^+ K^- \\pi^0, K^{*0} K^-\\pi^+$ and $p \\bar{p}$ decay\nchannels. The neutral $B^0$ channel is a CP eigenstate and can be used to\nmeasure the CP violation parameter $\\sin 2\\phi_1$. We also report the first\nobservation of the $B^0\\to \\eta_c K^{*0}$ mode. The results are based on an\nanalysis of 29.1 fb$^{-1}$ of data collected by the Belle detector at KEKB.", "category": "hep-ex" }, { "text": "Search for a massless dark photon in $\u039b^{+}_{c}\\to p\n \u03b3^{\\prime}$ decay: A search for a massless dark photon $\\gamma^{\\prime}$ is conducted using 4.5\n$\\mathrm{fb}^{-1}$ of $e^+e^-$ collision data collected at center-of-mass\nenergies between 4.600 and 4.699 $\\mathrm{GeV}$ with the BESIII detector at\nBEPCII. No significant signal is observed, and the upper limit on the branching\nfraction $\\mathcal{B}(\\Lambda^{+}_{c}\\to p \\gamma^{\\prime})$ is determined to\nbe $8.0\\times 10^{-5}$ at 90% confidence level.", "category": "hep-ex" }, { "text": "Spin Physics with the PHENIX Detector System: The PHENIX experiment at RHIC has extended its scope to cover spin physics\nusing polarized proton beams. The major goals of the spin physics at RHIC are\nelucidation of the spin structure of the nucleon and precision tests of the\nsymmetries. Sensitivities of the spin physics measurements with the PHENIX\ndetector system are reviewed.", "category": "hep-ex" }, { "text": "Measurement of the forward-backward asymmetry of electron and muon\n pair-production in $pp$ collisions at $\\sqrt{s}$ = 7 TeV with the ATLAS\n detector: This paper presents measurements from the ATLAS experiment of the\nforward-backward asymmetry in the reaction $pp\\rightarrow\nZ/\\gamma^{*}\\rightarrow l^{+}l^{-}$, with $l$ being electrons or muons, and the\nextraction of the effective weak mixing angle. The results are based on the\nfull set of data collected in 2011 in $pp$ collisions at the LHC at $\\sqrt{s}$\n= 7 TeV, corresponding to an integrated luminosity of 4.8 fb$^{-1}$. The\nmeasured asymmetry values are found to be in agreement with the corresponding\nStandard Model predictions. The combination of the muon and electron channels\nyields a value of the effective weak mixing angle of $0.2308 \\pm 0.0005\n\\mathrm{(stat.)} \\pm 0.0006 \\mathrm{(syst.)} \\pm 0.0009\\mathrm{(PDF)}$, where\nthe first uncertainty corresponds to data statistics,the second to systematic\neffects and the third to knowledge of the parton density functions. This result\nagrees with the current world average from the Particle Data Group fit.", "category": "hep-ex" }, { "text": "$\u03a5$ Production in Heavy-Ion Collisions from the STAR Experiment: In these proceedings, we present recent results of $\\Upsilon$ measurements in\nheavy-ion collisions from the STAR experiment at RHIC. Nuclear modification\nfactors ($R_{AA}$) for $\\Upsilon(1S)$ and $\\Upsilon(1S+2S+3S)$ in U+U\ncollisions at \\sqrtsNN\\ = 193 GeV are measured through the di-electron channel\nand compared to those in Au+Au collisions at \\sqrtsNN\\ = 200 GeV and Pb+Pb\ncollisions at \\sqrtsNN\\ = 2.76 TeV. The ratio between the $\\Upsilon(2S+3S)$ and\n$\\Upsilon(1S)$ yields in Au+Au collisions at \\sqrtsNN\\ = 200 GeV is measured in\nthe di-muon channel and compared to those in p+p collisions and in Pb+Pb\ncollisions at \\sqrtsNN\\ = 2.76 TeV. Prospects for future $\\Upsilon$\nmeasurements with the STAR experiment are also discussed.", "category": "hep-ex" }, { "text": "Search for a CP-odd Higgs boson decaying into a heavy CP-even Higgs\n boson and a $Z$ boson in the $\\ell^+\\ell^- t\\bar{t}$ and\n $\u03bd\\bar\u03bdb\\bar{b}$ final states using 140 fb$^{-1}$ of data collected\n with the ATLAS detector: A search for a heavy CP-odd Higgs boson, $A$, decaying into a $Z$ boson and a\nheavy CP-even Higgs boson, $H$, is presented. It uses the full LHC Run 2\ndataset of $pp$ collisions at $\\sqrt{s}=13$ TeV collected with the ATLAS\ndetector, corresponding to an integrated luminosity of $140$ fb$^{-1}$. The\nsearch for $A\\to ZH$ is performed in the $\\ell^+\\ell^- t\\bar{t}$ and\n$\\nu\\bar{\\nu}b\\bar{b}$ final states and surpasses the reach of previous\nsearches in different final states in the region with $m_H>350$ GeV and\n$m_A>800$ GeV. No significant deviation from the Standard Model expectation is\nfound. Upper limits are placed on the production cross-section times the decay\nbranching ratios. Limits with less model dependence are also presented as\nfunctions of the reconstructed $m(t\\bar{t})$ and $m(b\\bar{b})$ distributions in\nthe $\\ell^+\\ell^- t\\bar{t}$ and $\\nu\\bar{\\nu}b\\bar{b}$ channels, respectively.\nIn addition, the results are interpreted in the context of two-Higgs-doublet\nmodels.", "category": "hep-ex" }, { "text": "UV Irradiation Facility for Solar Effects Simulations: We describe an experimental setup developed aiming to irradiate samples under\nUV radiation for accelerated test for solar effects according to the relevant\nECSS-ESA standards. This facility has been already used for projects belonging\nto large space programs (Cosmic Vision, Artes) for simulations up to 3500\nequivalent sun hours. In particular, we detail the calculation of the UV dose\ndelivered by Sun, the calibration of the detectors, the spatial distribution of\nthe UV radiation on samples, the remote control of both samples temperature and\nlamp radiation, the samples heat dissipation and operation in a helium\natmosphere.", "category": "hep-ex" }, { "text": "The Double Chooz reactor neutrino experiment: The Double Chooz reactor neutrino experiment will be the next detector to\nsearch for a non vanishing theta13 mixing angle with unprecedented sensitivity,\nwhich might open the way to unveiling CP violation in the leptonic sector. The\nmeasurement of this angle will be based in a precise comparison of the\nantineutrino spectrum at two identical detectors located at different distances\nfrom the Chooz nuclear reactor cores in France. Double Chooz is particularly\nattractive because of its capability to measure sin2(2theta13) to 3 sigmas if\nsin2(2theta13) > 0.05 or to exclude sin2(2theta13) down to 0.03 at 90% C.L. for\nDm2 = 2.5 x 10-3 eV2 in three years of data taking with both detectors. The\nconstruction of the far detector starts in 2008 and the first neutrino results\nare expected in 2009. The current status of the experiment, its physics\npotential and design and expected performance of the detector are reviewed.", "category": "hep-ex" }, { "text": "Development of time-of-flight particle identification for future Higgs\n factories: With the emergence of advanced Silicon (Si) sensor technologies such as\nLGADs, it is now possible to achieve exceptional time measurement precision\nbelow 50 ps. As a result, the implementation of time-of-flight (TOF) particle\nidentification (PID) for charged hadrons at future $e^{+}e^{-}$ Higgs factory\ndetectors has gained increasing attention. Other PID techniques require a\ngaseous tracker with excellent dE/dx resolution, or a Ring-imaging Cherenkov\ndetector (RICH), which adds additional material in front of the calorimeter.\nTOF measurements can be implemented either in the outer layers of the tracker\nor in the electromagnetic calorimeter, and are thus particularly interesting as\na PID method for detector concepts based on all-silicon trackers and optimised\nfor particle-flow reconstruction. In this study, we will explore potential\nintegration scenarios of a TOF measurement in a future Higgs factory detector,\nusing the International Large Detector (ILD) as an example. We will focus on\nthe challenges associated with crucial components of TOF PID, namely track\nlength reconstruction and TOF measurements. The subsequent discussion will\nhighlight the vital impact of precise track length reconstruction and various\nTOF measurement techniques, including recently developed machine learning\napproaches. We will evaluate the performance in terms of $\\pi/K$ and $K/p$\nseparation as a function of momentum, and discuss potential physics\napplications.", "category": "hep-ex" }, { "text": "Search for contact interactions in opposite-sign dimuon events in pp\n collisions at sqrt(s) = 7 TeV: Results are reported from a search for the effects of contact interactions\nusing events with a high-mass, oppositely charged muon pair. The events are\ncollected in proton-proton collisions at sqrt(s) = 7 TeV using the Compact Muon\nSolenoid detector at the Large Hadron Collider. The data sample corresponds to\nan integrated luminosity of 5.3 inverse femtobarns. The observed dimuon mass\nspectrum is consistent with that expected from the standard model. The data are\ninterpreted in the context of a quark- and muon-compositeness model with a\nleft-handed isoscalar current and an energy scale parameter Lambda. The 95%\nconfidence level lower limit on Lambda is 9.5 TeV under the assumption of\ndestructive interference between the standard model and contact-interaction\namplitudes. For constructive interference, the limit is 13.1 TeV. These limits\nare comparable to the most stringent ones reported to date.", "category": "hep-ex" }, { "text": "Measurement of the charge asymmetry in top quark pair production in pp\n collisions at sqrt(s) = 8 TeV using a template method: The charge asymmetry in the production of top quark and antiquark pairs is\nmeasured in proton-proton collisions at a center-of-mass energy of 8 TeV. The\ndata, corresponding to an integrated luminosity of 19.6 inverse femtobarns,\nwere collected by the CMS experiment at the LHC. Events with a single isolated\nelectron or muon, and four or more jets, at least one of which is likely to\nhave originated from hadronization of a bottom quark, are selected. A template\ntechnique is used to measure the asymmetry in the distribution of differences\nin the top quark and antiquark absolute rapidities. The measured asymmetry is\nA[c,y] = [0.33 +/- 0.26 (stat) +/- 0.33 (syst)]%, which is the most precise\nresult to date. The results are compared to calculations based on the standard\nmodel and on several beyond-the-standard-model scenarios.", "category": "hep-ex" }, { "text": "Why is the Conclusion of the GERDA Experiment not Justified ?: The first results of the GERDA double beta experiment in Gran Sasso were\nrecently presented. They are fully consistent with the Heidelberg-Moscow\nexperiment, but because of its low statistics cannot proof anything at this\nmoment. It is no surprise that the statistics is still far from being able to\ntest the signal claimed by the HEIDELBERG-MOSCOW experiment. The energy\nresolution of the coaxial detectors is a factor of 1.5 worse than in the\nHEIDELBERG-MOSCOW experiment. The original goal of background reduction to\n10^{-2}counts/kgykeV, or by an order of magnitude compared to the\nHEIDELBERG-MOSCOW experiment, has not been reached. The background is only a\nfactor 2.3 lower if we refer it to the experimental line width, i.e. in units\ncounts/kgy energy resolution.\n With pulse shape analysis (PSA) the background in the HEIDELBERG-MOSCOW\nexperiment around Q_{\\beta\\beta} is 4x10^{-3} counts/kgykeV\n\\cite{HVKK-IVK-MPhLA2006}, which is a factor of 4 (5 referring to the line\nwidth) lower than that of GERDA with pulse shape analysis.\n The amount of enriched material used in the GERDA measurement is 14.6kg, only\na factor of 1.34 larger than that used in the HM experiment. The background\nmodel is oversimplified and not yet adequate. It is not shown that the lines of\ntheir background can be identified. GERDA has to continue the measurement\nfurther ~5years, until they can responsibly present an understood background.\nThe present half life limit presented by GERDA of T_{1/2}^{0\\nu} > 2.1 x\n10^{25} y (90% confidence level, i.e. 1.6sigma)) is still lower than the\nhalf-life of T_{1/2}^{0\\nu} = 2.23^{{+0.44}_{-0.31}} x 10^{25} y\n\\cite{HVKK-IVK-MPhLA2006} determined in the HEIDELBERG-MOSCOW experiment.", "category": "hep-ex" }, { "text": "Precision Measurement of CP Violation in D0->pi+pi- at CDF: We report a preliminary measurement of the CP violating asymmetry in\nD0->pi+pi- using approximately 215,000 decays reconstructed in about 5.94/fb of\nCDF data. We use the strong D*+->D0pi+ decay (\"D* tag\") to identify the flavor\nof the charmed meson at production time and exploit CP-conserving strong c-cbar\npair-production in p-pbar collisions. Higher statistic samples of\nCabibbo-favored D0->K-pi+ decays with and without D* tag are used to highly\nsuppress systematic uncertainties due to detector effects. The result is the\nworld's most precise measurement to date.", "category": "hep-ex" }, { "text": "Search for Single Top Production at the Tevatron: Searches for the electroweak production of single top quarks have been\nstarted at the Fermilab Tevatron proton-antiproton collider using Run II data\nby both the D0 and CDF collaborations. Using a dataset of approximately\n160pb^-1, neither experiment finds evidence for Single Top production and sets\n95% C.L. upper limits on the production cross section. The D0 limits are 19pb\non the s-channel production, 25pb on the t-channel production, and 23pb on the\ncombined s+t-channel production. The CDF limits are 8.5pb on the t-channel\nproduction and 13.7pb on the combined s+t-channel production.", "category": "hep-ex" }, { "text": "Study of Hadronic Five-Body Decays of Charmed Mesons: We study the decay of D+ and Ds+ mesons into charged five body final states,\nand report the discovery of the decay mode D+ -> K+K-Pi+Pi+Pi-, as well as\nmeasurements of the decay modes D+ -> K-Pi+Pi+Pi+Pi-, Ds+ -> K+K-Pi+Pi+Pi-, Ds+\n-> PhiPi+Pi+Pi- and D+/Ds+ -> Pi+Pi+Pi+Pi-Pi-. An analysis of the resonant\nsubstructure is also included, with evidence suggesting that both decays\nproceed primarily through an a1 vector resonance.", "category": "hep-ex" }, { "text": "Measurement of the production cross section of an isolated photon\n associated with jets in proton-proton collisions at sqrt(s) = 7 TeV with the\n ATLAS detector: A measurement of the cross section for the production of an isolated photon\nin association with jets in proton-proton collisions at a center-of-mass energy\nsqrt(s) = 7 TeV is presented. Photons are reconstructed in the pseudorapidity\nrange |eta(gamma)|<1.37 and with a transverse energy E_T(gamma)>25 GeV. Jets\nare reconstructed in the rapidity range |y(jet)|<4.4 and with a transverse\nmomentum p_T(jet)>20 GeV. The differential cross section dsigma/dE_T(gamma) is\nmeasured, as a function of the photon transverse energy, for three different\nrapidity ranges of the leading-p_T jet: |y(jet)|<1.2, 1.2<=|y(jet)|<2.8 and\n2.8<=|y(jet)|< 4.4. For each rapidity configuration the same-sign\n(eta(gamma)y(jet)>=0) and opposite-sign (eta(gamma)y(jet)<0) cases are studied\nseparately. The results are based on an integrated luminosity of 37 pb^-1,\ncollected with the ATLAS detector at the LHC. Next-to-leading order\nperturbative QCD calculations are found to be in fair agreement with the data,\nexcept for E_T(gamma)<~45 GeV, where the theoretical predictions overestimate\nthe measured cross sections.", "category": "hep-ex" }, { "text": "Search for narrow resonances using the dijet mass spectrum in pp\n collisions at sqrt(s) = 8 TeV: Results are presented of a search for the production of new particles\ndecaying to pairs of partons (quarks, antiquarks, or gluons), in the dijet mass\nspectrum in proton-proton collisions at sqrt(s) = 8 TeV. The data sample\ncorresponds to an integrated luminosity of 4.0 inverse femtobarns, collected\nwith the CMS detector at the LHC in 2012. No significant evidence for narrow\nresonance production is observed. Upper limits are set at the 95% confidence\nlevel on the production cross section of hypothetical new particles decaying to\nquark-quark, quark-gluon, or gluon-gluon final states. These limits are then\ntranslated into lower limits on the masses of new resonances in specific\nscenarios of physics beyond the standard model. The limits reach up to 4.8 TeV,\ndepending on the model, and extend previous exclusions from similar searches\nperformed at lower collision energies. For the first time mass limits are set\nfor the Randall-Sundrum graviton model in the dijet channel.", "category": "hep-ex" }, { "text": "Search for Free Fractional Electric Charge Elementary Particles: We have carried out a direct search in bulk matter for free fractional\nelectric charge elementary particles using the largest mass single sample ever\nstudied - about 17.4 mg of silicone oil. The search used an improved and highly\nautomated Millikan oil drop technique. No evidence for fractional charge\nparticles was found. The concentration of particles with fractional charge more\nthan 0.16e (e being the magnitude of the electron charge) from the nearest\ninteger charge is less than $4.71\\times10^{-22}$ particles per nucleon with 95%\nconfidence.", "category": "hep-ex" }, { "text": "Prospects at Future B Factories: Proceedings of CKM 2012, the 7th International Workshop on the CKM Unitarity\nTriangle, University of Cincinnati, USA, 28 September - 2 October 2012.\n A concise overview of the possibilities offered by high-luminosity B\nFactories in mixing and mixing-related CP violating processes in B decays is\npresented.", "category": "hep-ex" }, { "text": "Muon reconstruction and identification with the Run II D0 detector: We present an overview of the muon reconstruction and identification methods\nemployed by the D0 Collaboration to analyze the Run II (2001-2011) ppbar data\nof the Fermilab Tevatron collider at sqrt s = 1.96 TeV. We discuss the\nperformance of these methods, how it is measured using D0 data, and how it is\nproperly modeled by the D0 simulation program. In its pseudorapidity\nacceptance, eta< 2, the muon system identifies high-pT muons (pT>10 GeV) with\nefficiencies ranging from 72% to 89%. Muons tracks are reconstructed in the D0\ncentral tracking system with efficiencies ranging from 85% to 92% and with a\ntypical relative momentum resolution of 10% for pT = 40 GeV. Isolation criteria\nreject multijet background with efficiencies of 87% to 99%.", "category": "hep-ex" }, { "text": "$\\mathrm{t\\bar{t}H}$ production at $\\mathrm{13\\,TeV}$: In this paper, the latest results of searches for the standard model Higgs\nboson produced in association with a top quark-antiquark pair\n($\\mathrm{t\\bar{t}H}$), where Higgs decays into photons, bottom quark-antiquark\npair or leptons via $\\mathrm{WW^*}$, $\\mathrm{ZZ^*}$ and $\\mathrm{\\tau\\tau}$\nwill be presented. The analyses have been performed using the\n$\\mathrm{13\\,TeV}$ pp collisions data recorded by the CMS experiment in 2015\nand part of 2016. The results are presented in the form of the best fit to the\nsignal strength ($\\mathrm{\\mu=\\sigma/\\sigma_{SM}}$) measured with respect to\nthe Standard Model prediction and its expected and observed $\\mathrm{95\\%}$\nC.L. upper limits.", "category": "hep-ex" }, { "text": "Status Report of the MACRO Experiment for the year 2001: In this 2001 status report of the MACRO experiment, results are presented on\natmospheric neutrinos and neutrino oscillations, high energy neutrino\nastronomy, searches for WIMPs, search for low energy stellar gravitational\ncollapse neutrinos, stringent upper limits on GUT magnetic monopoles,\nnuclearites and lightly ionizing particles, high energy downgoing muons,\nprimary cosmic ray composition and shadowing of primary cosmic rays by the Moon\nand the Sun.", "category": "hep-ex" }, { "text": "Observation of $K^*(892)^0\\bar K^*(892)^0$ in $\u03c7_{cJ}$ Decays: $K^*(892)^0\\bar K^*(892)^0$ signals from $\\chi_{cJ} (J=0,1,2)$ decays are\nobserved for the first time using a data sample of 14 million $\\psi(2S)$ events\naccumulated at the BES II detector. The branching fractions ${\\cal\nB}(\\chi_{cJ}\\to K^*(892)^0\\bar K^*(892)^0)$ $(J = 0,1,2)$ are determined to be\n$(1.55 \\pm 0.35 \\pm 0.30)\\times 10^{-3}$, $(1.58 \\pm 0.32 \\pm 0.29)\\times\n10^{-3}$, and $(4.67 \\pm 0.55 \\pm 0.85)\\times 10^{-3}$ for the $\\chi_{c0}$,\n$\\chi_{c1}$ and $\\chi_{c2}$ decays, respectively, where the first errors are\nstatistical and the second are systematic. The significances of these signals\nare about 4.2$\\sigma$, 4.3$\\sigma$, and 7.5$\\sigma$, respectively.", "category": "hep-ex" }, { "text": "Search for a light charged Higgs boson decaying to c s-bar in pp\n collisions at sqrt(s) = 8 TeV: A search for a light charged Higgs boson, originating from the decay of a top\nquark and subsequently decaying into a charm quark and a strange antiquark, is\npresented. The data used in the analysis correspond to an integrated luminosity\nof 19.7 inverse femtobarns recorded in proton-proton collisions at sqrt(s) = 8\nTeV by the CMS experiment at the LHC. The search is performed in the process t\nt-bar to W+/- b H-/+ b-bar, where the W boson decays to a lepton (electron or\nmuon) and a neutrino. The decays lead to a final state comprising an isolated\nlepton, at least four jets and large missing transverse energy. No significant\ndeviation is observed in the data with respect to the standard model\npredictions, and model-independent upper limits are set on the branching\nfraction B(t to H+ b), ranging from 1.2 to 6.5% for a charged Higgs boson with\nmass between 90 and 160 GeV, under the assumption that B(H+ to c s-bar) = 100%.", "category": "hep-ex" }, { "text": "The monitoring system for the aerogel Cherenkov counter of the BELLE\n detector: We report on a design and performances of a monitoring system developed for\nthe aerogel Cherenkov counters (ACC) of the BELLE detector. The system consists\nof blue LEDs, a diffuser box, and optical distributors which distribute the LED\nlight to the ACC modules. The employed LED (NSPB series) has been observed to\nhave high reliability on the long term stability and the temprature dependence.\nThe diffuser box is employed to reduce the intrinsic non-uniformity of the LED\nlight intensity. The overall performances of the present monitoring system on\nuniformity and intensity of the light output have been found to satisfy all the\nrequirements for the monitoring.", "category": "hep-ex" }, { "text": "Transverse Polarization of Lambda and Lambda-bar Hyperons in Quasireal\n Photoproduction: The HERMES experiment has measured the transverse polarization of Lambda and\nLambda-bar hyperons produced inclusively in quasireal photoproduction at a\npositron beam energy of 27.6 GeV. The transverse polarization of the Lambda\nhyperon is found to be positive while the observed Lambda-bar polarization is\ncompatible with zero. The transverse polarization values averaged over the\nkinematic acceptance of HERMES are 0.078 +/- 0.006(stat) +/- 0.012(syst) and\n-0.025 +/- 0.015(stat) +/- 0.018(syst) for Lambda and Lambda-bar hyperons,\nrespectively. The dependences of Lambda and Lambda-bar polarizations on the\nfraction $\\zeta$ of the beam's light-cone momentum carried by the hyperon and\non the hyperon's transverse momentum $p_T$ were investigated. The measured\nLambda polarization rises linearly with $p_T$ and exhibits a different behavior\nfor low and high values of $\\zeta$, which approximately correspond to the\nbackward and forward regions in the center-of-mass frame of the $\\gamma^*N$\nreaction.", "category": "hep-ex" }, { "text": "Top quark and W/Z results from the Tevatron: We summarize results of some crucial measurements of the top quark and W/Z\nboson properties carried out by the D0 and the CDF collaborations at the\nTevatron collider at Fermilab based on data collected during Run 1 (1992-96).\nAmong the interesting properties measured are the pair-production cross section\nand the mass of the top quark, and the mass and the width of the W boson.\nSearches for singly produced top quarks and for certain non-standard production\nand decays of the top quark, as well as studies of angular correlations in the\nproduction and decay of the top quarks are also presented. Expectations from\nthe ongoing Run 2 of the Tevatron, presently in its second year, are discussed.", "category": "hep-ex" }, { "text": "Neutrino Characterisation using Convolutional Neural Networks in CHIPS\n water Cherenkov detectors: This work presents a novel approach to water Cherenkov neutrino detector\nevent reconstruction and classification. Three forms of a Convolutional Neural\nNetwork have been trained to reject cosmic muon events, classify beam events,\nand estimate neutrino energies, using only a slightly modified version of the\nraw detector event as input. When evaluated on a realistic selection of\nsimulated CHIPS-5kton prototype detector events, this new approach\nsignificantly increases performance over the standard likelihood-based\nreconstruction and simple neural network classification.", "category": "hep-ex" }, { "text": "Search for Lepton Flavor Violation in $\u03a5(3S)\\rightarrow\n e^{\\pm}\u03bc^{\\mp}$: We report on the first search for electron-muon lepton flavor violation (LFV)\nin the decay of a $b$~quark and $b$~antiquark bound state. We look for the LFV\ndecay $\\Upsilon (3S)\\rightarrow e^{\\pm}\\mu^{\\mp}$ in a sample of 118~million\n$\\Upsilon (3S)$ mesons from 27~fb$^{-1}$ of data collected with the \\babar\\\ndetector at the SLAC PEP-II $e^+e^-$ collider operating with a 10.36~GeV\ncenter-of-mass energy. No evidence for a signal is found and we set a limit on\nthe branching fraction $\\mathcal{B}(\\Upsilon(3S)\\rightarrow\ne^{\\pm}\\mu^{\\mp})<3.6\\times10^{-7}\\mathrm{at~ 90\\%~ CL}$. This result can be\ninterpreted as a limit $\\Lambda_{NP}/g^2_{NP} > 80~$TeV on the energy scale\n$\\Lambda_{NP}$ divided by the coupling-squared $g^2_{NP}$ of relevant new\nphysics.", "category": "hep-ex" }, { "text": "Dalitz plot analysis of the D^+ -> K^-pi^+pi^+ decay: We perform a Dalitz plot analysis of D^+ -> K^-pi^+pi^+ decay with the CLEO-c\ndata set of 572 pb^-1 of e^+e^- collisions accumulated at the psi(3770). This\ncorresponds to 1.6 million D^+D^- pairs from which we select 140793 candidate\nevents with a small background of 1.1%. We compare our results with previous\nmeasurements using the isobar model. We modify the isobar model with improved\ndescription of some of the contributing resonances, and get better agreement\nwith our data. We also consider a quasi-model-independent approach and measure\nthe magnitude and phase of the contributing K pi S wave in the range of\ninvariant masses from the threshold to the maximum in this decay. This gives an\nimproved descriptions of our data over the isobar model. Finally we allow for\nan isospin-two pi^+pi^+ S-wave contribution, and find that adding this to both\nthe isobar model and quasi-model-independent approach gives the best\ndescription of our data.", "category": "hep-ex" }, { "text": "Searches for exclusive Higgs and $Z$ boson decays into $J/\u03c8\u03b3$,\n $\u03c8(2S)\u03b3$, and $\u03a5(nS)\u03b3$ at $\\sqrt{s}=13$ TeV with the\n ATLAS detector: Searches for the exclusive decays of the Higgs and $Z$ bosons into a\n$J/\\psi$, $\\psi(2S)$, or $\\Upsilon(nS)$ ($n=1,2,3$) meson and a photon are\nperformed with a $pp$ collision data sample corresponding to an integrated\nluminosity of 36.1 fb$^{-1}$ collected at $\\sqrt{s}=13$ TeV with the ATLAS\ndetector at the CERN Large Hadron Collider. No significant excess of events is\nobserved above the expected backgrounds, and 95% confidence-level upper limits\non the branching fractions of the Higgs boson decays to $J/\\psi\\gamma$,\n$\\psi(2S)\\gamma$, and $\\Upsilon(nS)\\gamma$ of $3.5\\times10^{-4}$,\n$2.0\\times10^{-3}$, and $(4.9,5.9,5.7)\\times10^{-4}$, respectively, are\nobtained assuming Standard Model production. The corresponding 95%\nconfidence-level upper limits for the branching fractions of the $Z$ boson\ndecays are $2.3\\times10^{-6}$, $4.5\\times10^{-6}$ and\n$(2.8,1.7,4.8)\\times10^{-6}$, respectively.", "category": "hep-ex" }, { "text": "Measurement of the Absolute Branching Fraction of D0 -> K- pi+: We measure the absolute branching fraction for $D0 \\to K^{-} \\pi^{+}$ using\npartial reconstruction of $B0bar \\to D^{*+} X \\ell^{-} \\bar{\\nu}_{\\ell}$\ndecays. Only the charged lepton and the soft pion from the decay $D^{*+} \\to\nD^{0} \\pi^{+}$ are used. Based on a data sample of 230 million BBbar pairs\ncollected at the $\\Upsilon(4S)$ resonance with the \\babar detector at the\nPEP-II asymmetric-energy $B$ Factory at SLAC, we obtain ${\\cal B}(\\Dz \\to \\Km\n\\pip) = (4.025 \\pm 0.038 \\pm 0.098)%$, where the first error is statistical and\nthe second error is systematic.", "category": "hep-ex" }, { "text": "Search for production of single top quarks via flavor-changing neutral\n currents at the Tevatron: We search for the production of single top quarks via flavor-changing neutral\ncurrent couplings of a gluon to the top quark and a charm (c) or up (u) quark.\nWe analyze 230 pb^{-1} of lepton+jets data from \\ppbar collisions at a center\nof mass energy of 1.96 TeV collected by the D0 detector at the Fermilab\nTevatron Collider. We observe no significant deviation from standard model\npredictions, and hence set upper limits on anomalous coupling parameters\n\\kappa^c_g/\\Lambda and \\kappa^u_g/\\Lambda, where the \\kappa_g define the\nstrength of the tcg and tug couplings, and \\Lambda defines the scale of new\nphysics. The limits at 95% C.L. are: \\kappa^c_g/\\Lambda < 0.15 TeV^{-1} and\n\\kappa^u_g/\\Lambda < 0.037 TeV^{-1}.", "category": "hep-ex" }, { "text": "Heavy quark meson spectroscopy at CDF: From a study of the X(3872) mass and width based on the world's largest\nsample of $X(3872)\\to J/\\psi\\pi^+\\pi^-$ decays, we find that our X(3872) signal\nis consistent with a single state, and leads to the most precise measurement of\nthe X(3872) mass. We also report the recent evidence for a new narrow\nstructure, Y(4140), decaying to the $J/\\psi \\phi$ final state, in exclusive\n$B^+\\to J/\\psi\\phi K^+$ decays in a data sample corresponding to an integrated\nluminosity of 2.7 \\ifb collected at the CDF II detector. This narrow structure\nwith its mass well above open charm pairs is unlikely to be a candidate for a\nconventional charmonium state.", "category": "hep-ex" }, { "text": "Production of Slow Protonium in Vacuum: We describe how protonium, the quasi-stable antiproton-proton bound system,\nhas been synthesized following the interaction of antiprotons with the\nmolecular ion H$_2^+$ in a nested Penning trap environment. From a careful\nanalysis of the spatial distributions of antiproton annihilation events in the\nATHENA experiment, evidence is presented for protonium production with sub-eV\nkinetic energies in states around $n$ = 70, with low angular momenta. This work\nprovides a new 2-body system for study using laser spectroscopic techniques.", "category": "hep-ex" }, { "text": "Evidence for the decay B0 --> K+K-pi0: We report a search for charmless hadronic decays of neutral B mesons to the\nfinal state K+K-pi0. The results are based on a 711 fb^-1 data sample that\ncontains 772x10^6 BB-bar pairs, and was collected at the Y(4S) resonance with\nthe Belle detector at the KEKB asymmetric-energy e+e- collider. We find the\nfirst evidence for this decay with a significance of 3.5 standard deviations\nand measure its branching fraction as BF(B0 --> K+K-pi0) = [2.17 +/- 0.60(stat)\n+/- 0.24 (syst)]x10^-6.", "category": "hep-ex" }, { "text": "Measurement of the centrality dependence of the charged-particle\n pseudorapidity distribution in proton--lead collisions at\n $\\sqrt{s_{_{\\rm{NN}}}} = 5.02$ TeV with the ATLAS detector: The centrality dependence of the mean charged-particle multiplicity as a\nfunction of pseudorapidity is measured in approximately 1 $\\mu$b$^{-1}$ of\nproton--lead collisions at a nucleon--nucleon centre-of-mass energy of\n$\\sqrt{s_{_{\\rm{NN}}}} = 5.02$ TeV using the ATLAS detector at the Large Hadron\nCollider. Charged particles with absolute pseudorapidity less than 2.7 are\nreconstructed using the ATLAS pixel detector. The $p$+Pb collision centrality\nis characterised by the total transverse energy measured in the Pb-going\ndirection of the forward calorimeter. The charged-particle pseudorapidity\ndistributions are found to vary strongly with centrality, with an increasing\nasymmetry between the proton-going and Pb-going directions as the collisions\nbecome more central. Three different estimations of the number of nucleons\nparticipating in the $p$+Pb collision have been carried out using the Glauber\nmodel as well as two Glauber--Gribov inspired extensions to the Glauber model.\nCharged-particle multiplicities per participant pair are found to vary\ndifferently for these three models, highlighting the importance of including\ncolour fluctuations in nucleon--nucleon collisions in the modelling of the\ninitial state of $p$+Pb collisions.", "category": "hep-ex" }, { "text": "Evidence for the decay $B^0\\to J/\u03c8\u03c9$ and measurement of the\n relative branching fractions of $B^0_s$ meson decays to $J/\u03c8\u03b7$ and\n $J/\u03c8\u03b7^{'}$: First evidence of the $B^0\\to J/\\psi\\omega$ decay is found and the\n$B_{s}^0\\to J/\\psi\\eta$ and $B_{s}^0\\to J/\\psi\\eta^{\\prime}$ decays are studied\nusing a dataset corresponding to an integrated luminosity of 1.0\n$\\mathrm{fb}^{-1}$ collected by the LHCb experiment in proton-proton collisions\nat a centre-of-mass energy of $\\sqrt{s} = 7$ TeV. The branching fractions of\nthese decays are measured relative to that of the $\\mathrm{B}^0\\to\nJ/\\psi\\rho^0$ decay: $$\\frac{Br(B^0\\to J/\\psi\\omega)}{Br(B^0\\to J/\\psi\\rho^0)}\n= 0.89 \\pm0.19(stat)^{+0.07}_{-0.13}(syst)$$ $$\\frac{Br(B^0_s\\to\nJ/\\psi\\eta)}{Br(B^0\\to J/\\psi\\rho^0)} = 14.0 \\pm\n1.2(stat)^{+1.1}_{-1.5}(syst)^{+1.1}_{-1.0}(\\frac{f_d}{f_s}),$$\n$$\\frac{Br(B^0_s\\to J/\\psi\\eta^{\\prime})}{Br(B^0\\to J/\\psi\\rho^0)} =\n12.7\\pm1.1(stat)^{+0.5}_{-1.3}(syst)^{+1.0}_{-0.9}(\\frac{f_d}{f_s}),$$ where\nthe last uncertainty is due to the knowledge of $f_d/f_s$, the ratio of b-quark\nhadronization factors that accounts for the different production rate of $B^0$\nand $B^0_s$ mesons. The ratio of the branching fractions of $B^0_s\\to\nJ/\\psi\\eta^{\\prime}$ and $B^0_s\\to J/\\psi\\eta$ decays is measured to be $$\n\\frac{Br(B^0_s\\to J/\\psi\\eta^{\\prime})}{Br(B^0_s\\to J/\\psi\\eta)} =\n0.90\\pm0.09(stat)^{+0.06}_{-0.02}(syst).$$", "category": "hep-ex" }, { "text": "Prospects for X(3872) Detection at Panda: Monte-Carlo simulations for a resonance scan of the charmonium-like state\nX(3872) at Panda are performed. Final state radiation hadronic background\nreactions are taken into account. The signal reconstruction uses a realistic\npattern recognition (track finder and track fitter) and electron/pion\ndiscrimination.", "category": "hep-ex" }, { "text": "Neutrino Physics Opportunities with the IsoDAR Source at Yemilab: IsoDAR seeks to place a high-power-cyclotron and target combination, as an\nintense source of $\\bar{\\nu}_e$ at the level of $\\sim 10^{23}$/year, close to a\nkiloton-scale neutrino detector in order to gain sensitivity to very\nshort-baseline neutrino oscillations ($\\bar{\\nu}_e \\rightarrow \\bar{\\nu}_{e}$)\nand perform precision tests of the weak interaction, among other physics\nopportunities. Recently, IsoDAR has received preliminary approval to be paired\nwith the 2.26~kton target volume liquid scintillator detector at the Yemi\nUnderground Laboratory (Yemilab) in Korea, at a 17~m center-to-center baseline,\nand cavern excavation for IsoDAR is now complete. In this paper, we present the\nphysics capabilities of IsoDAR@Yemilab in terms of sensitivity to oscillations\n(via inverse beta decay, IBD; $\\bar{\\nu}_e+p \\rightarrow e^+ + n$), including\ninitial-state wavepacket effects, and the weak mixing angle (via elastic\nscattering off atomic electrons, $\\bar{\\nu}_e + e^- \\rightarrow \\bar{\\nu}_e +\ne^-$). We also introduce a study of IsoDAR sensitivity to new particles, such\nas a light $X$ boson, produced in the target that decays to $\\nu_e \\bar \\nu_e$.", "category": "hep-ex" }, { "text": "Precision Top Quark Mass Measurement in the Lepton + Jets Topology in\n ppbar Collisions at sqrt(s) = 1.96 TeV: We report two measurements of the top quark mass M_top using the CDF II\ndetector at the Fermilab Tevatron in a 318 pb^-1 data sample observed in the\nlepton + jets final state. One method uses an event-based likelihood technique\nresulting in M_top = 173.2 +2.6/-2.4 (stat.) +/- 3.2 (syst.) GeV/c^2 or 173.2\n+4.1/-4.0 GeV/c^2. The second method reconstructs a top quark mass in each\nevent using the measured invariant mass of the hadronically decaying W boson to\nconstrain the jet energy scale to obtain a value for M_top of 173.5 +3.7/-3.6\n(stat.) +/- 1.3 (syst.) GeV/c^2 or 173.5 +3.9/-3.8 GeV/c^2. We take the latter,\nwhich is more precise, as our result.", "category": "hep-ex" }, { "text": "Inclusive Charged Hadron Production in Two-Photon Collisions at LEP: Inclusive charged hadron production, e+e- -> e+e- h+- X, is studied using 414\npb-1 of data collected at LEP with the L3 detector at centre-of-mass energies\nbetween 189 and 202 GeV. Single particle inclusive differential cross sections\nare measured as a function of the particle transverse momentum, pt, and\npseudo-rapidity, eta. For p_t < 1.5 GeV, the data are well described by an\nexponential, typical of soft hadronic processes. For higher pt, the onset of\nperturbative QCD processes is observed. The pi+- production cross section for\npt > 5 GeV is much higher than the NLO QCD predictions.", "category": "hep-ex" }, { "text": "Study of the Baryon-Antibaryon Low-Mass Enhancements in Charmless\n Three-body Baryonic B Decays: The angular distributions of the baryon-antibaryon low-mass enhancements seen\nin the charmless three-body baryonic B decays B+ -> p pbar K+, B0 -> p pbar Ks,\nand B0 -> p Lambdabar pi- are reported. A quark fragmentation interpretation is\nsupported, while the gluonic resonance picture is disfavored. Searches for the\nTheta+ and Theta++ pentaquarks in the relevant decay modes and possible\nglueball states G with 2.2 GeV/c2 < M-ppbar < 2.4 GeV/c2 in the ppbar systems\ngive null results. We set upper limits on the products of branching fractions,\nB(B0 -> Theta+ p)\\times B(Theta+ -> p Ks) < 2.3 \\times 10^{-7}, B(B+ -> Theta++\npbar) \\times B(Theta++ -> p K+) < 9.1 \\times 10^{-8}, and B(B+ -> G K+) \\times\nB(G -> p pbar) < 4.1 \\times 10^{-7} at the 90% confidence level. The analysis\nis based on a 140 fb^{-1} data sample recorded on the Upsilon(4S) resonance\nwith the Belle detector at the KEKB asymmetric-energy e+e- collider.", "category": "hep-ex" }, { "text": "Observation of Two New N* Peaks in J/psi -> $p pi^- \\bar n$ and $\\bar\n p\u03c0^+n$ Decays: The $\\pi N$ system in decays of $J/\\psi\\to\\bar NN\\pi$ is limited to be\nisospin 1/2 by isospin conservation. This provides a big advantage in studying\n$N^*\\to \\pi N$ compared with $\\pi N$ and $\\gamma N$ experiments which mix\nisospin 1/2 and 3/2 for the $\\pi N$ system. Using 58 million $J/\\psi$ decays\ncollected with the Beijing Electron Positron Collider, more than 100 thousand\n$J/\\psi \\to p \\pi^- \\bar n + c.c.$ events are obtained. Besides two well known\n$N^*$ peaks at 1500 MeV and 1670 MeV, there are two new, clear $N^*$ peaks in\nthe $p\\pi$ invariant mass spectrum around 1360 MeV and 2030 MeV. They are the\nfirst direct observation of the $N^*(1440)$ peak and a long-sought \"missing\"\n$N^*$ peak above 2 GeV in the $\\pi N$ invariant mass spectrum. A simple\nBreit-Wigner fit gives the mass and width for the $N^*(1440)$ peak as $1358\\pm\n6 \\pm 16$ MeV and $179\\pm 26\\pm 50$ MeV, and for the new $N^*$ peak above 2 GeV\nas $2068\\pm 3^{+15}_{-40}$ MeV and $165\\pm 14\\pm 40$ MeV, respectively.", "category": "hep-ex" }, { "text": "Excess Electronic Recoil Events in XENON1T: We report results from searches for new physics with low-energy electronic\nrecoil data recorded with the XENON1T detector. With an exposure of 0.65 t-y\nand an unprecedentedly low background rate of $76\\pm2$ events/(t y keV) between\n1 and 30 keV, the data enables sensitive searches for solar axions, an enhanced\nneutrino magnetic moment, and bosonic dark matter. An excess over known\nbackgrounds is observed at low energies and most prominent between 2 and 3 keV.\nThe solar axion model has a 3.4$\\sigma$ significance, and a 3D 90% confidence\nsurface is reported for axion couplings to electrons, photons, and nucleons.\nThis surface is inscribed in the cuboid defined by $g_{ae}<3.8 \\times\n10^{-12}$, $g_{ae}g_{an}^{eff}<4.8\\times 10^{-18}$, and\n$g_{ae}g_{a\\gamma}<7.7\\times10^{-22} GeV^{-1}$, and excludes either $g_{ae}=0$\nor $g_{ae}g_{a\\gamma}=g_{ae}g_{an}^{eff}=0$. The neutrino magnetic moment\nsignal is similarly favored over background at 3.2$\\sigma$ and a confidence\ninterval of $\\mu_{\\nu} \\in (1.4,2.9)\\times10^{-11}\\mu_B$ (90% C.L.) is\nreported. Both results are in strong tension with stellar constraints. The\nexcess can also be explained by $\\beta$ decays of tritium at 3.2$\\sigma$ with a\ntrace amount that can neither be confirmed nor excluded with current knowledge\nof its production and reduction mechanisms. The significances of the solar\naxion and neutrino magnetic moment hypotheses are reduced to 2.0$\\sigma$ and\n0.9$\\sigma$, respectively, if an unconstrained tritium component is included in\nthe fitting. With respect to bosonic dark matter, the excess favors a\nmonoenergetic peak at ($2.3\\pm0.2$) keV (68% C.L.) with a 3.0$\\sigma$ global\n(4.0$\\sigma$ local) significance. We also consider the possibility that\n$^{37}$Ar may be present in the detector and yield a 2.82 keV peak. Contrary to\ntritium, the $^{37}$Ar concentration can be tightly constrained and is found to\nbe negligible.", "category": "hep-ex" }, { "text": "Measurement of indirect CP-violating asymmetries in $D^0\\to K^+K^-$ and\n $D^0\\to \u03c0^+\u03c0^-$ decays at CDF: We report a measurement of the indirect CP-violating asymmetries\n($A_{\\Gamma}$) between effective lifetimes of anticharm and charm mesons\nreconstructed in $D^0\\to K^+ K^-$ and $D^0\\to \\pi^+\\pi^-$ decays. We use the\nfull data set of proton-antiproton collisions collected by the Collider\nDetector at Fermilab experiment and corresponding to $9.7$~fb$^{-1}$ of\nintegrated luminosity. The strong-interaction decay $D^{*+}\\to D^0\\pi^+$ is\nused to identify the meson at production as $D^0$ or $\\overline{D}^0$. We\nstatistically subtract $D^0$ and $\\overline{D}^0$ mesons originating from\n$b$-hadron decays and measure the yield asymmetry between anticharm and charm\ndecays as a function of decay time. We measure $A_\\Gamma (K^+K^-) = (-0.19 \\pm\n0.15 (stat) \\pm 0.04 (syst))\\%$ and $A_\\Gamma (\\pi^+\\pi^-)= (-0.01 \\pm 0.18\n(stat) \\pm 0.03 (syst))\\%$. The results are consistent with the hypothesis of\nCP symmetry and their combination yields $A_\\Gamma = (-0.12 \\pm 0.12)\\%$.", "category": "hep-ex" }, { "text": "Precision Electroweak Physics at the Z: A review of the decade of Z-pole electroweak physics is presented. Although\nall experimental work has been completed, it represents a ``Golden Age'' in our\nunderstanding of the Minimal Electroweak Standard Model (MSM). The latest (and\nnearly final) results from the LEP and SLC experiments are presented. The\nremaining inconsistencies are discussed and and their effects upon the MSM\ninterpretation are explored.", "category": "hep-ex" } ]