WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7150

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Now showing 1 - 6 of 6
  • Article
    Citation - WoS: 65
    Citation - Scopus: 62
    Search for the standard model Higgs boson produced through vector boson fusion and decaying to b¯b
    (American Physical Society, 2015) CMS Collaboration; Karapınar, Güler
    A first search is reported for a standard model Higgs boson (H) that is produced through vector boson fusion and decays to a bottom-quark pair. Two data samples, corresponding to integrated luminosities of 19.8fb-1 and 18.3fb-1 of proton-proton collisions at s=8TeV were selected for this channel at the CERN LHC. The observed significance in these data samples for a H→bb¯ signal at a mass of 125 GeV is 2.2 standard deviations, while the expected significance is 0.8 standard deviations. The fitted signal strength μ=σ/σSM=2.8-1.4+1.6. The combination of this result with other CMS searches for the Higgs boson decaying to a b-quark pair yields a signal strength of 1.0±0.4, corresponding to a signal significance of 2.6 standard deviations for a Higgs boson mass of 125 GeV. © 2015 CERN.
  • Article
    Citation - WoS: 35
    Citation - Scopus: 93
    Search for Resonant and Nonresonant Higgs Boson Pair Production in the B B ¯final State in Proton-Proton Collisions at ?s=13 Tev
    (Springer Verlag, 2018) CMS Collaboration; Karapınar, Güler
    Searches for resonant and nonresonant pair-produced Higgs bosons (HH) decaying respectively into , through either W or Z bosons, and b b ¯ are presented. The analyses are based on a sample of proton-proton collisions at s=13 TeV, collected by the CMS experiment at the LHC, corresponding to an integrated luminosity of 35.9 fb −1 . Data and predictions from the standard model are in agreement within uncertainties. For the standard model HH hypothesis, the data exclude at 95% confidence level a product of the production cross section and branching fraction larger than 72 fb, corresponding to 79 times the standard model prediction. Constraints are placed on different scenarios considering anomalous couplings, which could affect the rate and kinematics of HH production. Upper limits at 95% confidence level are set on the production cross section of narrow-width spin-0 and spin-2 particles decaying to Higgs boson pairs, the latter produced with minimal gravity-like coupling.
  • Article
    Citation - WoS: 24
    Citation - Scopus: 26
    Pseudorapidity Distributions of Charged Hadrons in Proton-Lead Collisions at ?snn=5.02 and 8.16 Tev
    (Springer Verlag, 2018) CMS Collaboration; Karapınar, Güler
    The pseudorapidity distributions of charged hadrons in proton-lead collisions at nucleon-nucleon center-of-mass energies sNN=5.02 and 8.16 TeV are presented. The measurements are based on data samples collected by the CMS experiment at the LHC. The number of primary charged hadrons produced in non-single-diffractive proton-lead collisions is determined in the pseudorapidity range |η lab | < 2.4. The charged-hadron multiplicity distributions are compared to the predictions from theoretical calculations and Monte Carlo event generators. In the center-of-mass pseudorapidity range |η cm | < 0.5, the average charged-hadron multiplicity densities 〈dN ch /dη cm 〉 |ηcm| < 0.5 are 17.31 ± 0.01 (stat) ± 0.59 (syst) and 20.10 ± 0.01 (stat) ± 0.85(syst) at sNN=5.02 and 8.16 TeV, respectively. The particle densities per participant nucleon are compared to similar measurements in proton-proton, proton-nucleus, and nucleus-nucleus collisions.
  • Article
    Citation - WoS: 5
    Citation - Scopus: 6
    Production of Leading Charged Particles and Leading Charged-Particle Jets at Small Transverse Momenta in Pp Collisions at Sqrt(s) = 8 Tev
    (American Physical Society, 2015) CMS Collaboration; Karapınar, Güler
    The per-event yield of the highest transverse momentum charged particle and charged-particle jet, integrated above a given pTmin threshold starting at pTmin=0.8 and 1 GeV, respectively, is studied in pp collisions at s=8 TeV. The particles and the jets are measured in the pseudorapidity ranges |η|<2.4 and 1.9, respectively. The data are sensitive to the momentum scale at which parton densities saturate in the proton, to multiple partonic interactions, and to other key aspects of the transition between the soft and hard QCD regimes in hadronic collisions. © 2015 CERN, for the CMS Collaboration. Published by the American Physical Society under the terms of the »http://creativecommons.org/licenses/by/3.0/» Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.
  • Article
    Citation - WoS: 22
    Citation - Scopus: 38
    Combined Search for the Quarks of a Sequential Fourth Generation
    (American Physical Society, 2012) CMS Collaboration; Karapınar, Güler
    Results are presented from a search for a fourth generation of quarks produced singly or in pairs in a data set corresponding to an integrated luminosity of 5fb-1 recorded by the CMS experiment at the LHC in 2011. A novel strategy has been developed for a combined search for quarks of the up and down type in decay channels with at least one isolated muon or electron. Limits on the mass of the fourth-generation quarks and the relevant Cabibbo-Kobayashi-Maskawa matrix elements are derived in the context of a simple extension of the standard model with a sequential fourth generation of fermions. The existence of mass-degenerate fourth-generation quarks with masses below 685GeV is excluded at 95% confidence level for minimal off-diagonal mixing between the third- and the fourth-generation quarks. With a mass difference of 25GeV between the quark masses, the obtained limit on the masses of the fourth-generation quarks shifts by about ±20GeV. These results significantly reduce the allowed parameter space for a fourth generation of fermions. © 2012 CERN.
  • Article
    Citation - WoS: 20
    Citation - Scopus: 45
    Search for Pair Production of First- and Second-Generation Scalar Leptoquarks in Pp Collisions at ?s=7tev
    (American Physical Society, 2012) CMS Collaboration; Karapınar, Güler
    Results are presented from a search for the pair production of first- and second-generation scalar leptoquarks in proton-proton collisions at √s=7TeV. The data sample corresponds to an integrated luminosity of 5.0fb -1, collected by the CMS detector at the LHC. The search signatures involve either two charged leptons of the same flavor (electrons or muons) and at least two jets or a single charged lepton (electron or muon), missing transverse energy, and at least two jets. If the branching fraction of the leptoquark decay into a charged lepton and a quark is assumed to be β=1, leptoquark pair production is excluded at the 95% confidence level for masses below 830 GeV and 840 GeV for the first and second generations, respectively. For β=0.5, masses below 640 GeV and 650 GeV are excluded. These limits are the most stringent to date. © 2012 CERN.