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: 90Citation - Scopus: 137Measurement of the Inclusive Jet Cross Section in Pp Collisions at ?s=7tev(American Physical Society, 2011) Karapınar, Güler; Demir, Durmuş AliThe inclusive jet cross section is measured in pp collisions with a center-of-mass energy of 7 TeV at the Large Hadron Collider using the CMS experiment. The data sample corresponds to an integrated luminosity of 34pb -1. The measurement is made for jet transverse momenta in the range 18-1100 GeV and for absolute values of rapidity less than 3. The measured cross section extends to the highest values of jet pT ever observed and, within the experimental and theoretical uncertainties, is generally in agreement with next-to-leading-order perturbative QCD predictions. © 2011 CERNArticle Citation - WoS: 71Citation - Scopus: 88Measurement of the Differential Cross Section for Isolated Prompt Photon Production in Pp Collisions at 7 Tev(American Physical Society, 2011) Karapınar, Güler; Demir, Durmuş AliA measurement of the differential cross section for the inclusive production of isolated prompt photons in proton-proton collisions at a center-of-mass energy of 7 TeV is presented. The data sample corresponds to an integrated luminosity of 36pb-1 recorded by the CMS detector at the LHC. The measurement covers the pseudorapidity range |η|<2.5 and the transverse energy range 25<ET<400GeV, corresponding to the kinematic region 0.007<xT<0.114. Photon candidates are identified with two complementary methods, one based on photon conversions in the silicon tracker and the other on isolated energy deposits in the electromagnetic calorimeter. The measured cross section is presented as a function of ET in four pseudorapidity regions. The next-to-leading-order perturbative QCD calculations are consistent with the measured cross section. © 2011 CERN.Article Citation - WoS: 175Citation - Scopus: 144Charged Particle Multiplicities in Pp Interactions at ?s = 0.9, 2.36, and 7tev(Springer Verlag, 2011) Karapınar, Güler; Demir, Durmuş AliMeasurements of primary charged hadron multiplicity distributions are presented for non-single-diffractive events in proton-proton collisions at centre-of-mass energies of √s = 0.9, 2.36, and 7TeV, in five pseudorapidity ranges from |η| < 0.5 to |η| < 2.4. The data were collected with the minimum-bias trigger of the CMS experiment during the LHC commissioning runs in 2009 and the 7TeV run in 2010. The multiplicity distribution at √s = 0.9 TeV is in agreement with previous measurements. At higher energies the increase of the mean multiplicity with √s is underestimated by most event generators. The average transverse momentum as a function of the multiplicity is also presented. The measurement of higher-order moments of the multiplicity distribution confirms the violation of Koba-Nielsen-Olesen scaling that has been observed at lower energies.Article Citation - WoS: 23Citation - Scopus: 65Measurement of Bb¯ Angular Correlations Based on Secondary Vertex Reconstruction at ?s = 7 Tev(Springer Verlag, 2011) Karapınar, Güler; Demir, Durmuş AliA measurement of the angular correlations between beauty and anti-beauty hadrons (BB̄) produced in pp collisions at a centre-of-mass energy of 7 TeV at the CERN LHC is presented, probing for the first time the region of small angular separation. The B hadrons are identified by the presence of displaced secondary vertices from their decays. The B hadron angular separation is reconstructed from the decay vertices and the primaryinteraction vertex. The differential BB̄ production cross section, measured from a data sample collected by CMS and corresponding to an integrated luminosity of 3.1 pb -1, shows that a sizable fraction of the BB̄ pairs are produced with small opening angles. These studies provide a test of QCD and further insight into the dynamics of bb̄ production.Article Citation - WoS: 17Citation - Scopus: 32Inclusive B-Hadron Production Cross Section With Muons in Pp Collisions at ?s = 7 Tev(Springer Verlag, 2011) Karapınar, Güler; Demir, Durmuş AliA measurement of the b-hadron production cross section in proton-proton collisions at √s = 7TeV is presented. The dataset, corresponding to 85 nb-1, was recorded with the CMS experiment at the LHC using a low-threshold single-muon trigger. Events are selected by the presence of a muon with transverse momentum pμ T > 6GeV with respect to the beam direction and pseudorapidity |ζμ| < 2.1. The transverse momentum of the muon with respect to the closest jet discriminates events containing b hadrons from background. The inclusive b-hadron production cross section is presented as a function of muon transverse momentum and pseudorapidity. The measured total cross section in the kinematic acceptance is σ(pp → b + X → μ + X′) = 1.32 ± 0.01(stat) ± 0.30(syst) ± 0.15(lumi)μb.Article Citation - WoS: 242Citation - Scopus: 228Measurements of Inclusive W and Z Cross Sections in Pp Collisions at ?s = 7 Tev the Cms Collaboration(Springer Verlag, 2011) Karapınar, Güler; Demir, Durmuş AliMeasurements of inclusive W and Z boson production cross sections in pp collisions at √s = 7 TeV are presented, based on 2.9 pb-1 of data recorded by the CMS detector at the LHC. The measurements, performed in the electron and muon decay channels, are combined to give σ(pp → WX) × B(W → l?) = 9.95 ± 0.07 (stat.) ± 0.28 (syst.) ± 1.09 (lumi.) nb and σ(pp → ZX) × B(Z → l +l-) = 0.931 ± 0.026 (stat.) ± 0.023 (syst.) ± 0.102 (lumi.) nb, where l stands for either e or μ. Theoretical predictions, calculated at the next-to-next-to-leading order in QCD using recent parton distribution functions, are in agreement with the measured cross sections. Ratios of cross sections, which incur an experimental systematic uncertainty of less than 4%, are also reported.Article Citation - WoS: 48Citation - Scopus: 55Search for Bs0??+?- and B0??+?- Decays in Pp Collisions at ?s=7tev(American Physical Society, 2011) Karapınar, Güler; Demir, Durmuş AliA search for the rare decays Bs0→μ+μ- and B0→μ+μ- is performed in pp collisions at √s=7TeV, with a data sample corresponding to an integrated luminosity of 1.14fb-1, collected by the CMS experiment at the LHC. In both cases, the number of events observed after all selection requirements is consistent with expectations from background and standard-model signal predictions. The resulting upper limits on the branching fractions are B(Bs0→μ +μ-)<1.9×10-8 and B(B0→μ+μ-)<4.6×10-9, at 95% confidence level. © 2011 CERN.Article Citation - WoS: 61Citation - Scopus: 71Measurement of the Tt¯ Production Cross Section in Pp Collisions at 7 Tev in Lepton+jets Events Using B-Quark Jet Identification(American Physical Society, 2011) Karapınar, Güler; Demir, Durmuş AliA new measurement of the inclusive production cross section for pp→tt̄ is performed at a center-of-mass energy of 7 TeV using data collected by the CMS experiment at the LHC. The analysis uses a data sample corresponding to an integrated luminosity of 36pb-1, and is based on the final state with one isolated, high transverse momentum muon or electron, missing transverse energy, and hadronic jets. The tt̄ content of the selected events is enhanced by requiring the presence of at least one jet consistent with b-quark hadronization. The measured cross section is 150±9(stat)±17(syst)±6(lumi)pb and is in agreement with higher-order QCD calculations. The combination of this measurement with a previous CMS result based on dileptons gives 154±17(stat+syst) ±6(lumi)pb. © 2011 CERN.Article Citation - WoS: 52Citation - Scopus: 47Measurement of the Drell-Yan Cross Section in Pp Collisions at ? S = 7 Tev(Springer Verlag, 2011) Karapınar, Güler; Demir, Durmuş AliThe Drell-Yan differential cross section is measured in pp collisions at √ s = 7TeV, from a data sample collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 36 pb-1. The cross section measurement, normalized to the measured cross section in the Z region, is reported for both the dimuon and dielectron channels in the dilepton invariant mass range 15{600 GeV. The normalized cross section values are quoted both in the full phase space and within the detector acceptance. The effect of final state radiation is also identified. The results are found to agree with theoretical predictions. Copyright CERN.Article Citation - WoS: 255Citation - Scopus: 228Measurement of the Inclusive W and Z Production Cross Sections in Pp Collisions at ?s = 7 Tev With the Cms Experiment(Springer Verlag, 2011) Karapınar, Güler; Demir, Durmuş AliA measurement of inclusive W and Z production cross sections in pp collisions at √s = 7TeV is presented. The electron and muon decay channels are analyzed in a data sample collected with the CMS detector at the LHC and corresponding to an integrated luminosity of 36 pb-1. The measured inclusive cross sections are σ(pp → WX) × ß(W → lν) = 10.31 × 0.02 (stat.) × 0.09 (syst.) × 0.10 (th.) × 0.41 (lumi.) nb and σ(pp → ZX) x B(Z → l +l- = 0.974 × 0.007 (stat.) × 0.007 (syst.) × 0.018 (th.) × 0.039 (lumi.) nb, limited to the dilepton invariant mass range 60 to 120 GeV. The luminosity-independent cross section ratios are (σ(pp → WX) × B(W → lv))/(σ(pp → ZX) × B(Z → l+l-)) = 10.54 × 0.07 (stat.) × 0.08 (syst.) × 0.16 (th.) and (σ(pp → W+X) × B(W+ → l+ν))/(σ(pp → W-X) × B(W- → l-v̄)) = 1.421×0.006 (stat.) ×0.014 (syst.) ×0.029 (th.). The measured values agree with next-to-next-to-leading order QCD cross section calculations based on recent parton distribution functions. Copyright CERN.