Physics / Fizik
Permanent URI for this collectionhttps://hdl.handle.net/11147/6
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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; Karapınar, Güler; Demir, Durmuş Ali; 04.05. Department of Pyhsics; 01. Izmir Institute of Technology; 04. Faculty of ScienceThe 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 Ali; Karapınar, Güler; 04.05. Department of Pyhsics; 01. Izmir Institute of Technology; 04. Faculty of ScienceA 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: 48Citation - Scopus: 55Search for Bs0??+?- and B0??+?- Decays in Pp Collisions at ?s=7tev(American Physical Society, 2011) Karapınar, Güler; Demir, Durmuş Ali; Karapınar, Güler; 04.05. Department of Pyhsics; 01. Izmir Institute of Technology; 04. Faculty of ScienceA 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 Ali; Karapınar, Güler; 04.05. Department of Pyhsics; 01. Izmir Institute of Technology; 04. Faculty of ScienceA 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: 63Citation - Scopus: 69Inclusive Search for Squarks and Gluinos in Pp Collisions at Root S=7 Tev(American Physical Society, 2012) Demir, Durmuş Ali; Karapınar, Güler; Karapınar, Güler; 04.05. Department of Pyhsics; 01. Izmir Institute of Technology; 04. Faculty of ScienceA search is performed for heavy particle pairs produced in √s=7TeV proton-proton collisions with 35pb -1 of data collected by the CMS experiment at the LHC. The search is sensitive to squarks and gluinos of generic supersymmetry models, provided they are kinematically accessible, with minimal assumptions on properties of the lightest superpartner particle. The kinematic consistency of the selected events is tested against the hypothesis of heavy particle pair production using the dimensionless razor variable R, related to the missing transverse energy ETmiss. The new physics signal is characterized by a broad peak in the distribution of M R, an event-by-event indicator of the heavy particle mass scale. This new approach is complementary to ETmiss-based searches. After background modeling based on data, and background rejection based on R and M R, no significant excess of events is found beyond the standard model expectations. The results are interpreted in the context of the constrained minimal supersymmetric standard model as well as two simplified supersymmetry models. © 2012 CERN.