Yazar "Dragicevic M." seçeneğine göre listele

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    Measurement of the electroweak production of Formula Presented in association with two jets in proton-proton collisions at Formula Presented
    (American Physical Society, 2023) Tumasyan A.; Adam W.; Andrejkovic J.W.; Bergauer T.; Chatterjee S.; Damanakis K.; Dragicevic M.
    A measurement is presented for the electroweak production of a Formula Presented boson, a photon (Formula Presented), and two jets (j) in proton-proton collisions. The leptonic decay of the Formula Presented boson is selected by requiring one identified electron or muon and large missing transverse momentum. The two jets are required to have large invariant dijet mass and large separation in pseudorapidity. The measurement is performed with the data collected by the CMS detector at a center-of-mass energy of Formula Presented, corresponding to an integrated luminosity of Formula Presented. The cross section for the electroweak Formula Presented production is Formula Presented, whereas the total cross section for Formula Presented production is Formula Presented. Differential cross sections are also measured with the distributions unfolded to the particle level. All results are in agreement with the standard model expectations. Constraints are placed on anomalous quartic gauge couplings (aQGCs) in terms of dimension-8 effective field theory operators. These are the most stringent limits to date on the aQGCs parameters Formula Presented and Formula Presented. © 2023 CERN, for the CMS Collaboration.
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    Measurement of the production cross section for a W boson in association with a charm quark in proton–proton collisions at ?s=13TeV
    (Institute for Ionics, 2024) Tumasyan A.; Adam W.; Andrejkovic J.W.; Bergauer T.; Chatterjee S.; Damanakis K.; Dragicevic M.
    The strange quark content of the proton is probed through the measurement of the production cross section for a W boson and a charm (c) quark in proton–proton collisions at a center-of-mass energy of 13 TeV . The analysis uses a data sample corresponding to a total integrated luminosity of 138 fb-1 collected with the CMS detector at the LHC. The W bosons are identified through their leptonic decays to an electron or a muon, and a neutrino. Charm jets are tagged using the presence of a muon or a secondary vertex inside the jet. The W + c production cross section and the cross section ratio Rc±=?(W++c¯)/?(W-+c) are measured inclusively and differentially as functions of the transverse momentum and the pseudorapidity of the lepton originating from the W boson decay. The precision of the measurements is improved with respect to previous studies, reaching 1% in Rc±=0.950±0.005(stat)±0.010(syst) . The measurements are compared with theoretical predictions up to next-to-next-to-leading order in perturbative quantum chromodynamics. © 2024, The Author(s).
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    Probing Small Bjorken-x Nuclear Gluonic Structure via Coherent J=? Photoproduction in Ultraperipheral Pb-Pb Collisions at ?sNN = 5.02 TeV
    (American Physical Society, 2023) Tumasyan A.; Adam W.; Andrejkovic J.W.; Bergauer T.; Chatterjee S.; Damanakis K.; Dragicevic M.
    Quasireal photons exchanged in relativistic heavy ion interactions are powerful probes of the gluonic structure of nuclei. The coherent J=? photoproduction cross section in ultraperipheral lead-lead collisions is measured as a function of photon-nucleus center-of-mass energies per nucleon (WPb?N) over a wide range of 40 < WPb?N < 400 GeV. Results are obtained using data at the nucleon-nucleon center-of-mass energy of 5.02 TeV collected by the CMS experiment at the CERN LHC, corresponding to an integrated luminosity of 1.52 nb?1. The cross section is observed to rise rapidly at low WPb?N, and plateau above WPb?N ? 40 GeV, up to 400 GeV, entering a new regime of small Bjorken-x (?6 × 10?5) gluons being probed in a heavy nucleus. The observed energy dependence is not predicted by current quantum chromodynamic models. © 2023 CERN, for the CMS Collaboration.
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    A search for new physics in central exclusive production using the missing mass technique with the CMS detector and the CMS-TOTEM precision proton spectrometer
    (Institute for Ionics, 2023) Tumasyan A.; Adam W.; Andrejkovic J.W.; Bergauer T.; Chatterjee S.; Damanakis K.; Dragicevic M.
    A generic search is presented for the associated production of a Z boson or a photon with an additional unspecified massive particle X, pp ? pp + Z / ? + X , in proton-tagged events from proton–proton collisions at s=13TeV , recorded in 2017 with the CMS detector and the CMS-TOTEM precision proton spectrometer. The missing mass spectrum is analysed in the 600–1600 GeV range and a fit is performed to search for possible deviations from the background expectation. No significant excess in data with respect to the background predictions has been observed. Model-independent upper limits on the visible production cross section of pp ? pp + Z / ? + X are set. © 2023, The Author(s).