WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7150
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Article Citation - WoS: 12Citation - Scopus: 19Search for Charged-Lepton Flavor Violation in Top Quark Production and Decay in Pp Collisions at Root S=13 Tev(Springer, 2022) Tumasyan, A.; Karapınar, Güler; Karapınar, Güler; 01. Izmir Institute of TechnologyResults are presented from a search for charged-lepton flavor violating (CLFV) interactions in top quark production and decay in pp collisions at a center-of-mass energy of 13 TeV. The events are required to contain one oppositely charged electron-muon pair in the final state, along with at least one jet identified as originating from a bottom quark. The data correspond to an integrated luminosity of 138 fb(-1), collected by the CMS experiment at the LHC. This analysis includes both the production (q -> e mu t) and decay (t -> e mu q) modes of the top quark through CLFV interactions, with q referring to a u or c quark. These interactions are parametrized using an effective field theory approach. With no significant excess over the standard model expectation, the results are interpreted in terms of vector-, scalar-, and tensor-like CLFV four-fermion effective interactions. Finally, observed exclusion limits are set at 95% confidence levels on the respective branching fractions of a top quark to an e mu pair and an up (charm) quark of 0.13 x 10(-6) (1.31 x 10(-6)), 0.07 x 10(-6) (0.89 x 10(-6)), and 0.25 x 10(-6) (2.59 x 10(-6)) for vector, scalar, and tensor CLFV interactions, respectively.Article Citation - WoS: 11Citation - Scopus: 16Measurement of the Inclusive T(t)over-Bar Production Cross Section in Proton-Proton Collisions at Root S=5.02 Tev(Springer, 2022) Karapınar, Güler; Karapınar, Güler; 01. Izmir Institute of TechnologyThe top quark pair production cross section is measured in proton-proton collisions at a center-of-mass energy of 5.02 TeV. The data were collected in a special LHC low-energy and low-intensity run in 2017, and correspond to an integrated luminosity of 302 pb(-1). The measurement is performed using events with one electron and one muon of opposite charge, and at least two jets. The measured cross section is 60.7 +/- 5.0 (stat) +/- 2.8 (syst) +/- 1.1 (lumi) pb. A combination with the result in the single lepton + jets channel, based on data collected in 2015 at the same center-of-mass energy and corresponding to an integrated luminosity of 27.4 pb(-1), is then performed. The resulting measured value is 63.0 +/- 4.1 (stat) +/- 3.0 (syst+lumi) pb, in agreement with the standard model prediction of 66.8(-3.1)(+2.9) pb.Article Citation - WoS: 29Citation - Scopus: 33Measurement of the Cross Section Ratio Σtt¯bb¯/Σtt¯jj in Pp Collisions at S=8 Tev(Elsevier B.V., 2015) Karapınar, Güler; Karapınar, Güler; Bergauer, T.; Dragicevic, M.; Malgeri, L.; Tumasyan, A.; 01. Izmir Institute of TechnologyThe first measurement of the cross section ratio σtt¯bb¯/σtt¯jj is presented using a data sample corresponding to an integrated luminosity of 19.6 fb−1 collected in pp collisions at s=8 TeV with the CMS detector at the LHC. Events with two leptons (e or μ) and four reconstructed jets, including two identified as b quark jets, in the final state are selected. The ratio is determined for a minimum jet transverse momentum pT of both 20 and 40 GeV/c. The measured ratio is 0.022±0.003(stat)±0.005(syst) for pT>20 GeV/c. The absolute cross sections σtt¯bb¯ and σtt¯jj are also measured. The measured ratio for pT>40 GeV/c is compatible with a theoretical quantum chromodynamics calculation at next-to-leading order. © 2015 CERN for the benefit of the CMS Collaboration