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: 27Citation - Scopus: 63Evidence for Electroweak Production of Four Charged Leptons and Two Jets in Proton-Proton Collisions at S=13tev(Elsevier B.V., 2021) Sirunyan,A.M.; Karapınar, Güler; Tumasyan,A.; Adam,W.; Ambrogi,F.; Bergauer,T.; Dragicevic,M.; Chistov,R.Evidence is presented for the electroweak (EW) production of two jets (jj) in association with two Z bosons and constraints on anomalous quartic gauge couplings are set. The analysis is based on a data sample of proton-proton collisions at s=13TeV collected with the CMS detector in 2016–2018, and corresponding to an integrated luminosity of 137fb−1. The search is performed in the fully leptonic final state ZZ→ℓℓℓ′ℓ′, where ℓ,ℓ′=e,μ. The EW production of two jets in association with two Z bosons is measured with an observed (expected) significance of 4.0 (3.5) standard deviations. The cross sections for the EW production are measured in three fiducial volumes and the result is σEW(pp→ZZjj→ℓℓℓ′ℓ′jj)=0.33−0.10 +0.11(stat)−0.03 +0.04(syst)fb in the most inclusive volume, in agreement with the standard model prediction of 0.275±0.021fb. Measurements of total cross sections for jj production in association with two Z bosons are also reported. Limits on anomalous quartic gauge couplings are derived in terms of the effective field theory operators T0, T1, T2, T8, and T9. © 2020 The Author(s)Article Citation - WoS: 84Search for Microscopic Black Hole Signatures at the Large Hadron Collider(Elsevier Ltd., 2011) Karapınar, GülerA search for microscopic black hole production and decay in pp collisions at a center-of-mass energy of 7 TeV has been conducted by the CMS Collaboration at the LHC, using a data sample corresponding to an integrated luminosity of 35 pb(-1). Events with large total transverse energy are analyzed for the presence of multiple high-energy jets, leptons, and photons, typical of a signal expected from a microscopic black hole. Good agreement with the standard model backgrounds, dominated by QCD multijet production, is observed for various final-state multiplicities and model-independent limits on new physics in these final states are set. Using simple semi-classical approximation, limits on the minimum black hole mass are derived as well, in the range 3.5-4.5 TeV. These are the first direct limits on black hole production at a particle accelerator. (c) 2011 CERN. Published by Elsevier B.V. All rights reserved.Article Citation - WoS: 52Measurement of the Differential Dijet Production Cross Section in Proton-Proton Collisions at Root S=7 Tev(Elsevier Ltd., 2011) Karapınar, GülerA measurement of the double-differential inclusive dijet production cross section in proton-proton collisions at root s = 7 TeV is presented as a function of the dijet invariant mass and jet rapidity. The data correspond to an integrated luminosity of 36 pb(-1), recorded with the CMS detector at the LHC. The measurement covers the dijet mass range 0.2 TeV to 3.5 TeV and jet rapidities up to vertical bar y vertical bar = 2.5. It is found to be in good agreement with next-to-leading-order QCD predictions. (C) 2011 CERN. Published by Elsevier B.V. All rights reserved.Article Citation - WoS: 28Search for a Heavy Bottom-Like Quark in Pp Collisions at Root S=7 Tev(Elsevier Ltd., 2011) Demir, Durmuş Ali; Karapınar, GülerA search for pair-produced bottom-like quarks in pp collisions at root s = 7 TeV is conducted with the CMS experiment at the LHC. The decay b' -> tW is considered in this search. The b'(b) over bar' tW-(t) over barW(+) process can be identified by the distinctive signature of trileptons and same-sign dileptons. With a data sample corresponding to an integrated luminosity of 34 pb(-1), no excess above the standard model background predictions is observed and a b' quark with a mass between 255 and 361 GeV/c(2) is excluded at the 95% confidence level. (C) 2011 CERN. Published by Elsevier B.V. All rights reserved.Article Citation - WoS: 21Measurement of the Ratio of the 3-Jet To 2-Jet Cross Sections in Pp Collisions at Root S=7 Tev(Elsevier Ltd., 2011) Demir, Durmuş Ali; Karapınar, GülerA measurement of the ratio of the inclusive 3-jet to 2-jet cross sections as a function of the total jet transverse momentum. HT, in the range 0.2 < H-T < 2.5 TeV is presented. The data have been collected at a proton-proton centre-of-mass energy of 7 TeV with the CMS detector at the LHC, and correspond to an integrated luminosity of 36 pb(-1). Comparisons are made between the data and the predictions of different QCD-based Monte Carlo models for multijet production. All models considered in this study are consistent with the data for H-T > 0.5 TeV. This measurement extends to an H-T range that has not been explored before. (C) 2011 CERN. Published by Elsevier B.V. All rights reserved.Article Citation - WoS: 33Search for Physics Beyond the Standard Model Using Multilepton Signatures in Pp Collisions at Root S=7 Tev(Elsevier Ltd., 2011) Demir, Durmuş Ali; Karapınar, GülerA search for physics beyond the standard model in events with at least three leptons and any number of jets is presented. The data sample corresponds to 35 pb(-1) of integrated luminosity in pp collisions at root s = 7 TeV collected by the CMS experiment at the LHC. A number of exclusive multileptonic channels are investigated and standard model backgrounds are suppressed by requiring sufficient missing transverse energy, invariant mass inconsistent with that of the Z boson, or high jet activity. Control samples in data are used to ascertain the robustness of background evaluation techniques and to minimise the reliance on simulation. The observations are consistent with background expectations. These results constrain previously unexplored regions of supersymmetric parameter space. (C) 2011 CERN. Published by Elsevier B.V. All rights reserved.Article Citation - WoS: 13A Search for Excited Leptons in Pp Collisions at Root S=7 Tev(Elsevier Ltd., 2011) Karapınar, GülerA search for excited leptons is carried out with the CMS detector at the LHC, using 36 pb(-1) of pp collision data recorded at root s = 7 TeV. The search is performed for associated production of a lepton and an oppositely charged excited lepton pp -> ll*, followed by the decay l* -> l gamma, resulting in the eey final state, where l = e, mu. No excess of events above the standard model expectation is observed. Interpreting the findings in the context of l* production through four-fermion contact interactions and subsequent decay via electroweak processes, first upper limits are reported for l* production at this collision energy. The exclusion region in the compositeness scale A and excited lepton mass M-l* parameter space is extended beyond previously established limits. For Lambda = M-l*, excited lepton masses are excluded below 1070 GeV/c(2) for e* and 1090 GeV/c(2) for mu* at the 95% confidence level. (C) 2011 CERN. Published by Elsevier B.V. All rights reserved.Article Citation - WoS: 73Inclusive and Differential Measurements of the T(t)over-Bar Charge Asymmetry in Proton-Proton Collisions Root S=7 Tev(Elsevier Ltd., 2012) Karapınar, GülerThe t (t) over bar charge asymmetry is measured in events containing a charged lepton (electron or muon) and at least four jets, one of which is identified as originating from b-quark hadronization. The analyzed dataset corresponds to an integrated luminosity of 5.0 fb(-1) collected with the CMS detector at the LHC. An inclusive and three differential measurements of the t (t) over bar charge asymmetry as a function of rapidity, transverse momentum, and invariant mass of the t (t) over bar system are presented. The measured inclusive t (t) over bar charge asymmetry is A(C) = 0.004 +/- 0.010 (stat.) +/- 0.011 (syst.). This result and the three differential measurements are consistent with zero asymmetry as well as with the predictions of the standard model. (C) 2012 CERN. Published by Elsevier B.V. All rights reserved.Article Citation - WoS: 39Search for Heavy Lepton Partners of Neutrinos in Proton-Proton Collisions in the Context of the Type Iii Seesaw Mechanism(Elsevier Ltd., 2012) Karapınar, GülerA search is presented in proton-proton collisions at root s = 7 TeV for fermionic triplet states expected in type Ill seesaw models. The search is performed using final states with three isolated charged leptons and an imbalance in transverse momentum. The data, collected with the CMS detector at the LHC, correspond to an integrated luminosity of 4.9 fb(-1). No excess of events is observed above the background predicted by the standard model, and the results are interpreted in terms of limits on production cross sections and masses of the heavy partners of the neutrinos in type Ill seesaw models. Depending on the considered scenarios, lower limits are obtained on the mass of the heavy partner of the neutrino that range from 180 to 210 GeV. These are the first limits on the production of type III seesaw fermionic triplet states reported by an experiment at the LHC. (C) 2012 CERN. Published by Elsevier B.V. All rights reserved.Article Citation - WoS: 48Search for Pair Produced Fourth-Generation Up-Type Quarks in Pp Collisions at Root S=7 Tev With a Lepton in the Final State(Elsevier Ltd., 2012) Karapınar, GülerThe results of a search for the pair production of a fourth-generation up-type quark (t') in proton-proton collisions at root s = 7 TeV are presented, using data corresponding to an integrated luminosity of about 5.0 fb(-1) collected by the Compact Muon Solenoid experiment at the LHC. The t' quark is assumed to decay exclusively to a W boson and a b quark. Events with a single isolated electron or muon, missing transverse momentum, and at least four hadronic jets, of which at least one must be identified as a b jet, are selected. No significant excess of events over standard model expectations is observed. Upper limits for the t'(t) over bar' production cross section at 95% confidence level are set as a function of t' mass, and t'-quark production for masses below 570 GeV is excluded. The search is equally sensitive to nonchiral heavy quarks decaying to Wb. In this case, the results can be interpreted as upper limits on the production cross section times the branching fraction to Wb. (C) 2012 CERN. Published by Elsevier B.V. All rights reserved.