Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Citation - WoS: 54Citation - Scopus: 59Measurement of the WZ Production Cross Section in pp Collisions at S=13 TeV(Elsevier, 2017) Khachatryan, V.; Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Asilar, E.; Bergauer, T.; Woods, N.The WZ production cross section in proton-proton collisions at root s = 13 Tev is measured with the CMS experiment at the LHC using a data sample corresponding to an integrated luminosity of 2.3 fb(-1). The measurement is performed in the leptonic decay modes WZ -> lVl'l', where l,l'=e,mu. The measured cross section for the range 60<m (l'l') <120 GeV is sigma(pp -> WZ) = 39.9 +/- 3.2(stat)(2.9)(-3.1)(syst)+/- 0.4(theo)+/- 1.3(lumi)pb, consistent with the standard model prediction.Article Citation - WoS: 31Citation - Scopus: 44Angular Analysis of the Decay B+ → K+μ+μ- in Proton-Proton Collisions at √s=8 TeV(Amer Physical Soc, 2018) Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Ambrogi, F.; Asilar, E.; Bergauer, T.; Woods, N.The angular distribution of the flavor-changing neutral current decay B+ -> K+mu(+)mu(-) is studied in proton-proton collisions at a center-of-mass energy of 8 TeV. The analysis is based on data collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 20.5 fb(-1). The forward-backward asymmetry A(FB) of the dimuon system and the contribution F-H from the pseudoscalar, scalar, and tensor amplitudes to the decay width are measured as a function of the dimuon mass squared. The measurements are consistent with the standard model expectations.Article Citation - WoS: 15Citation - Scopus: 18Search for Supersymmetry in pp Collisions at √s=13 TeV in the Single-Lepton Final State Using the Sum of Masses of Large-Radius Jets(Amer Physical Soc, 2017) Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Ambrogi, F.; Asilar, E.; Bergauer, T.; Woods, N.Results are reported from a search for supersymmetric particles in proton-proton collisions in the final state with a single lepton, multiple jets, including at least one b-tagged jet, and large missing transverse momentum. The search uses a sample of proton-proton collision data at root s = 13 TeV recorded by the CMS experiment at the LHC, corresponding to an integrated luminosity of 35.9 fb(-1). The observed event yields in the signal regions are consistent with those expected from standard model backgrounds. The results are interpreted in the context of simplified models of supersymmetry involving gluino pair production, with gluino decay into either on- or off-mass-shell top squarks. Assuming that the top squarks decay into a top quark plus a stable, weakly interacting neutralino, scenarios with gluino masses up to about 1.9 TeV are excluded at 95% confidence level for neutralino masses up to about 1 TeV.Article Citation - WoS: 24Citation - Scopus: 25Search for Supersymmetry in Pp Collisions at √s = 13 TeV in the Single-Lepton Final State Using the Sum of Masses of Large-Radius Jets(Springer Science and Business Media Deutschland GmbH, 2016) Khachatryan, V.; Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Asilar, E.; Bergauer, T.; Woods, N.Results are reported from a search for supersymmetric particles in protonproton collisions in the final state with a single, high transverse momentum lepton; multiple jets, including at least one b-tagged jet; and large missing transverse momentum. The data sample corresponds to an integrated luminosity of 2: 3 fb(-1) at root s = 13TeV, recorded by the CMS experiment at the LHC. The search focuses on processes leading to high jet multiplicities, such as gluino pair production with (g) over tilde -> t (t) over bar(chi) over tilde (0)(1) . The quantity M-J, defined as the sum of the masses of the large-radius jets in the event, is used in conjunction with other kinematic variables to provide discrimination between signal and background and as a key part of the background estimation method. The observed event yields in the signal regions in data are consistent with those expected for standard model backgrounds, estimated from control regions in data. Exclusion limits are obtained for a simplified model corresponding to gluino pair production with three-body decays into top quarks and neutralinos. Gluinos with a mass below 1600 GeV are excluded at a 95% confidence level for scenarios with low (chi) over tilde (0)(1) mass, and neutralinos with a mass below 800 GeV are excluded for a gluino mass of about 1300 GeV. For models with two-body gluino decays producing on-shell top squarks, the excluded region is only weakly sensitive to the top squark mass.Erratum Citation - WoS: 13Citation - Scopus: 9Erratum: Measurement of the Tt̄ Production Cross Section in the Dilepton Channel in pp Collisions at √s = 8 TeV (Journal of High Energy Physics (2014) 02 (024))(Springer Verlag, 2014) Chatrchyan, S.; Khachatryan, V.; Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Bergauer, T.; Smith, W. H.Article Citation - WoS: 1Citation - Scopus: 7Measurement of Differential Cross Sections for the Production of a Z Boson in Association With Jets in Proton-Proton Collisions at P S=13 Tev(AMER PHYSICAL SOC, 2023) Tumasyan, A.; Adam, W.; Andrejkovic, J. W.; Bergauer, T.; Chatterjee, S.; Dragicevic, M.; Del Valle, EscalanteA measurement is presented of the production of Z bosons that decay into two electrons or muons in association with jets, in proton-proton collisions at a center-of-mass energy of 13 TeV. The data were cross sections are measured as a function of the transverse momentum (pT) of the Z boson and the transverse momentum and rapidities of the five jets with largest pT. The jet multiplicity distribution is measured for up to eight jets. The hadronic activity in the events is estimated using the scalar sum of the pT of all the jets. All measurements are unfolded to the stable-particle level and compared with predictions from various Monte Carlo event generators, as well as with expectations at leading and next-to-leading orders in perturbative quantum chromodynamics.Article Citation - WoS: 6Citation - Scopus: 10Azimuthal Correlations Within Exclusive Dijets With Large Momentum Transfer in Photon-Lead Collisions(Amer Physical Soc, 2023) Tumasyan, A.; Adam, W.; Bergauer, T.; Dragicevic, M.; Del Valle, A. Escalante; Fruhwirth, R.; Zhokin, A.The structure of nucleons is multidimensional and depends on the transverse momenta, spatial geometry, and polarization of the constituent partons. Such a structure can be studied using high-energy photons produced in ultraperipheral heavy-ion collisions. The first measurement of the azimuthal angular correlations of exclusively produced events with two jets in photon-lead interactions at large momentum transfer is presented, a process that is considered to be sensitive to the underlying nuclear gluon polarization. This study uses a data sample of ultraperipheral lead-lead collisions at ffiffiffiffiffiffiffi p = 5.02 TeV, corresponding to sNN an integrated luminosity of 0.38 nb-1, collected with the CMS experiment at the LHC. The measured second harmonic of the correlation between the sum and difference of the two jet transverse momentum vectors is found to be positive, and rising, as the dijet transverse momentum increases. A well-tuned model that has been successful at describing a wide range of proton scattering data from the HERA experiments fails to describe the observed correlations, suggesting the presence of gluon polarization effects.Article Citation - WoS: 4Citation - Scopus: 3Search for Cp Violating Top Quark Couplings in Pp Collisions at √s = 13 Tev(Springer Science and Business Media Deutschland GmbH, 2023) Tumasyan, A.; Adam, W.; Bergauer, T.; Dragicevic, M.; Escalante, Del, Valle, A.; Frühwirth, R.; Jeitler, M.Results are presented from a search for CP violation in top quark pair production, using proton-proton collisions at a center-of-mass energy of 13 TeV. The data used for this analysis consist of final states with two charged leptons collected by the CMS experiment, and correspond to an integrated luminosity of 35.9 fb−1. The search uses two observables, O1 and O3, which are Lorentz scalars. The observable O1 is constructed from the four-momenta of the charged leptons and the reconstructed top quarks, while O3 consists of the four-momenta of the charged leptons and the b quarks originating from the top quarks. Asymmetries in these observables are sensitive to CP violation, and their measurement is used to determine the chromoelectric dipole moment of the top quark. The results are consistent with the expectation from the standard model. [Figure not available: see fulltext.]. © 2023, The Author(s).Article Citation - WoS: 20Citation - Scopus: 31Search for Flavor-Changing Neutral Current Interactions of the Top Quark and Higgs Boson in Final States With Two Photons in Proton-Proton Collisions at S =13 Tev(American Physical Society, 2022) Tumasyan, A.; Adam, W.; Andrejkovic, J.W.; Bergauer, T.; Chatterjee, S.; Dragicevic, M.; Bunichev, V.Proton-proton interactions resulting in final states with two photons are studied in a search for the signature of flavor-changing neutral current interactions of top quarks (t) and Higgs bosons (H). The analysis is based on data collected at a center-of-mass energy of 13 TeV with the CMS detector at the LHC, corresponding to an integrated luminosity of 137 fb-1. No significant excess above the background prediction is observed. Upper limits on the branching fractions (B) of the top quark decaying to a Higgs boson and an up (u) or charm (c) quark are derived through a binned fit to the diphoton invariant mass spectrum. The observed (expected) 95% confidence level upper limits are found to be 0.019% (0.031%) for B(t→Hu) and 0.073% (0.051%) for B(t→Hc). These are the strictest upper limits yet determined. © 2022 CERN.Article Citation - WoS: 22Citation - Scopus: 25Observation of the Bc+ Meson in Pb-Pb and Pp Collisions at Snn =5.02 Tev and Measurement of Its Nuclear Modification Factor(American Physical Society, 2022) Tumasyan, A.; Adam, W.; Andrejkovic, J.W.; Bergauer, T.; Chatterjee, S.; Dragicevic, M.; Boos, E.The Bc+ meson is observed for the first time in heavy ion collisions. Data from the CMS detector are used to study the production of the Bc+ meson in lead-lead (Pb-Pb) and proton-proton (pp) collisions at a center-of-mass energy per nucleon pair of sNN=5.02 TeV, via the Bc+→(J/ψ→μ+μ-)μ+νμ decay. The Bc+ nuclear modification factor, derived from the Pb-Pb-to-pp ratio of production cross sections, is measured in two bins of the trimuon transverse momentum and of the Pb-Pb collision centrality. The Bc+ meson is shown to be less suppressed than quarkonia and most of the open heavy-flavor mesons, suggesting that effects of the hot and dense nuclear matter created in heavy ion collisions contribute to its production. This measurement sets forth a promising new probe of the interplay of suppression and enhancement mechanisms in the production of heavy-flavor mesons in the quark-gluon plasma. © 2022 CERN.