Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Other Citation - WoS: 26Citation - Scopus: 17Erratum To: Search for the Associated Production of the Higgs Boson With a Top-Quark Pair(Springer Verlag, 2014) CMS Collaboration; Karapınar, GülerArticle Citation - WoS: 109Citation - Scopus: 112Search for the Associated Production of the Higgs Boson With a Top-Quark Pair(Springer Verlag, 2014) CMS Collaboration; Karapınar, GülerA search for the standard model Higgs boson produced in association with a top-quark pair t t ¯ H \left(\mathrm{t}\overline{\mathrm{t}}\mathrm{H}\right) is presented, using data samples corresponding to integrated luminosities of up to 5.1 fb-1and 19.7 fb-1collected in pp collisions at center-of-mass energies of 7 TeV and 8 TeV respectively. The search is based on the following signatures of the Higgs boson decay: H → hadrons, H → photons, and H → leptons. The results are characterized by an observed t t ¯ H \mathrm{t}\overline{\mathrm{t}}\mathrm{H} signal strength relative to the standard model cross section, μ=σ/σ SM,under the assumption that the Higgs boson decays as expected in the standard model. The best fit value is μ = 2.8 ± 1.0 for a Higgs boson mass of 125.6 GeV. [Figure not available: see fulltext.] © 2014 The Author(s).Article Citation - WoS: 25Citation - Scopus: 34Measurement of the Cross Section and Angular Correlations for Associated Production of a Z Boson With B Hadrons in Pp Collisions at ?s = 7 Tev(Springer Verlag, 2013) CMS Collaboration; Karapınar, GülerA study of proton-proton collisions in which two b hadrons are produced in association with a Z boson is reported. The collisions were recorded at a centre-of-mass energy of 7TeV with the CMS detector at the LHC, for an integrated luminosity of 5:2 fb-1. The b hadrons are identified by means of displaced secondary vertices, without the use of reconstructed jets, permitting the study of b-hadron pair production at small angular separation. Differential cross sections are presented as a function of the angular separation of the b hadrons and the Z boson. In addition, inclusive measurements are presented. For both the inclusive and differential studies, different ranges of Z boson momentum are considered, and each measurement is compared to the predictions from different event generators at leading-order and next-to-leading-order accuracy. Copyright CERN.Article Citation - WoS: 17Citation - Scopus: 15Search for Stopped Long-Lived Particles Produced in Pp Collisions at ?s = 7 Tev(Springer Verlag, 2012) CMS Collaboration; Karapınar, GülerA search has been performed for long-lived particles that have stopped in the CMS detector, during 7TeV proton-proton operations of the CERN LHC. The existence of such particles could be inferred from observation of their decays when there were no protonproton collisions in the CMS detector, namely during gaps between LHC beam crossings. Using a data set in which CMS recorded an integrated luminosity of 4.0 fb -1, and a search interval corresponding to 246 hours of trigger live time, 12 events are observed, with a mean background prediction of 8:6 ± 2:4 events. Limits are presented at 95% confidence level on long-lived gluino and stop production, over 13 orders of magnitude of particle lifetime. Assuming the "cloud model" of R-hadron interactions, a gluino with mass below 640 GeV and a stop with mass below 340 GeV are excluded, for lifetimes between 10 μs and 1000 s.Article Citation - WoS: 156Citation - Scopus: 130Search for a Light Charged Higgs Boson in Top Quark Decays in Pp Collisions at ?s = 7 Tev(Springer Verlag, 2012) CMS Collaboration; Karapınar, GülerResults are presented on a search for a light charged Higgs boson that can be produced in the decay of the top quark t → H +b and which, in turn, decays into τ +ν t. The analysed data correspond to an integrated luminosity of about 2 fb -1 recorded in protonproton collisions at √s = 7 TeV by the CMS experiment at the LHC. The search is sensitive to the decays of the top quark pairs tt̄ → H ±W ∓bb̄ and tt̄ → H ±H ∓bb̄. Various final states have been studied separately, all requiring presence of a τ lepton from H + decays, missing transverse energy, and multiple jets. Upper limits on the branching fraction B(t → H +b) in the range of 2-4% are established for charged Higgs boson masses between 80 and 160 GeV, under the assumption that B(H + → τ +ν τ) = 1.Article Citation - WoS: 87Citation - Scopus: 115Measurement of the B+ Production Cross Section in Pp Collisions at ?s=7tev(American Physical Society, 2011) Karapınar, Güler; Demir, Durmuş AliMeasurements of the total and differential cross sections dσ/dpTB and dσ/dyB for B+ mesons produced in pp collisions at √s=7TeV are presented. The data correspond to an integrated luminosity of 5.8pb-1 collected by the CMS experiment operating at the LHC. The exclusive decay B+→J/ψK+, with J/ψ→μ+μ-, is used to detect B+ mesons and to measure the production cross section as a function of pTB and yB. The total cross section for pTB>5GeV and |yB|<2.4 is measured to be 28.1±2.4±2.0±3.1μb, where the first uncertainty is statistical, the second is systematic, and the last is from the luminosity measurement. © 2011 American Physical Society.Article Citation - WoS: 95Citation - Scopus: 117Upsilon Production Cross Section in Pp Collisions at ?s=7tev(American Physical Society, 2011) Karapınar, Güler; Demir, Durmuş AliThe Υ(1S), Υ(2S), and Υ(3S) production cross sections in proton-proton collisions at √s=7TeV are measured using a data sample collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 3.1±0.3pb -1. Integrated over the rapidity range |y|<2, we find the product of the Υ(1S) production cross section and branching fraction to dimuons to be σ(pp→Υ(1S)X) •B(Υ(1S)→μ +μ -)=7.37±0.13-0. 42+0.61±0.81nb, where the first uncertainty is statistical, the second is systematic, and the third is associated with the estimation of the integrated luminosity of the data sample. This cross section is obtained assuming unpolarized Υ(1S) production. With the assumption of fully transverse or fully longitudinal production polarization, the measured cross section changes by about 20%. We also report the measurement of the Υ(1S), Υ(2S), and Υ(3S) differential cross sections as a function of transverse momentum and rapidity. © 2011 American Physical Society.Article Citation - WoS: 73Citation - Scopus: 74Measurement of the B0 Production Cross Section in Pp Collisions at √s=7tev(American Physical Society, 2011) Karapınar, Güler; Demir, Durmuş AliMeasurements of the differential production cross sections dσ/dpTB and dσ/dyB for B0 mesons produced in pp collisions at √s=7TeV are presented. The data set used was collected by the CMS experiment at the LHC and corresponds to an integrated luminosity of 40pb-1. The production cross section is measured from B0 meson decays reconstructed in the exclusive final state J/ψKS0, with the subsequent decays J/ψ→μ +μ- and KS0→π+π-. The total cross section for pTB>5GeV and <2.2 is measured to be 33.2±2.5±3.5μb, where the first uncertainty is statistical and the second is systematic. © 2011 American Physical Society.Article Citation - WoS: 610Citation - Scopus: 672Observation and Studies of Jet Quenching in Pbpb Collisions at ?snn=2.76 Tev(American Physical Society, 2011) Karapınar, Güler; Demir, Durmuş AliJet production in PbPb collisions at a nucleon-nucleon center-of-mass energy of 2.76 TeV was studied with the Compact Muon Solenoid (CMS) detector at the LHC, using a data sample corresponding to an integrated luminosity of 6.7μb-1. Jets are reconstructed using the energy deposited in the CMS calorimeters and studied as a function of collision centrality. With increasing collision centrality, a striking imbalance in dijet transverse momentum is observed, consistent with jet quenching. The observed effect extends from the lower cutoff used in this study (jet pT=120 GeV/c) up to the statistical limit of the available data sample (jet pT≈210 GeV/c). Correlations of charged particle tracks with jets indicate that the momentum imbalance is accompanied by a softening of the fragmentation pattern of the second most energetic, away-side jet. The dijet momentum balance is recovered when integrating low transverse momentum particles distributed over a wide angular range relative to the direction of the away-side jet. © 2011 American Physical Society.Article Citation - WoS: 37Citation - Scopus: 62Measurement of the Bs0 Production Cross Section With Bs0?j/? Decays in Pp Collisions at ?s=7tev(American Physical Society, 2011) Karapınar, Güler; Demir, Durmuş AliThe Bs0 differential production cross section is measured as functions of the transverse momentum and rapidity in pp collisions at √s=7TeV, using the Bs0→J/ψ decay, and compared with predictions based on perturbative QCD calculations at next-to-leading order. The data sample, collected by the CMS experiment at the LHC, corresponds to an integrated luminosity of 40pb -1. The Bs0 is reconstructed from the decays J/ ψ→μ+μ- and →K+K -. The integrated Bs0 cross section times Bs0→J/ψ branching fraction in the range 8<pTB<50GeV/c and |yB|<2.4 is measured to be 6.9±0.6±0.6nb, where the first uncertainty is statistical and the second is systematic. © 2011 CERN.