Rectorate / Rektörlük

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Now showing 1 - 10 of 23
  • Article
    An Empirical Study of Sequential Offer Bargaining During the Festival of Sacrifice
    (Elsevier, 2024) Dindaroğlu, Burak; Ertaç, Seda
    We report results from a unique data set of real -life bargaining transactions collected from the market for livestock (sheep) before the Festival of Sacrifice (Eid al-Adha) in Izmir, Turkey. This market is characterized by frequent and aggressive bargaining, which occurs in the form of sequential price offers. We record bargaining transactions as they occur, and collect detailed information on the bargaining environment, as well as on the characteristics of buyers and sellers. We also elicit each seller's outside option by means of an incentive compatible mechanism and obtain a reported maximum willingness to pay from buyers. We particularly focus on aspects of the bargaining process, such as non -price communication. In different types of empirical analysis, results robustly indicate that the presence and content of communication matters, for the likelihood of a sale as well as concessions made. Specifically, buyer -side communication is associated with larger concessions from the seller and a higher probability of sale. The presence of a mediator during the negotiation is associated with a higher probability of sale as well, while it has no effect on prices. We also provide results on the relative importance of groups of variables for predicting bargaining outcomes, which can provide directions for further research in bargaining.
  • Article
    Citation - WoS: 8
    Citation - Scopus: 6
    Search for High-Mass Resonances Decaying To a Jet and a Lorentz-Boosted Resonance in Proton-Proton Collisions at Root S=13 Tev
    (Elsevier, 2022) Karapınar, Güler
    A search is reported for high-mass hadronic resonances that decay to a parton and a Lorentz-boosted resonance, which in turn decays into a pair of partons. The search is based on data collected with the CMS detector at the LHC in proton-proton collisions at root s = 13 TeV, corresponding to an integrated luminosity of 138 fb(-1). The boosted resonance is reconstructed as a single wide jet with substructure consistent with a two-body decay. The high-mass resonance is thus considered as a dijet system. The jet substructure information and the kinematic properties of cascade resonance decays are exploited to disentangle the signal from the large quantum chromodynamics multijet background. The dijet mass spectrum is analyzed for the presence of new high-mass resonances, and is found to be consistent with the standard model background predictions. Results are interpreted in a warped extra dimension model where the high-mass resonance is a Kaluza-Klein gluon, the boosted resonance is a radion, and the final state partons are all gluons. Limits on the production cross section are set as a function of the Kaluza-Klein gluon and radion masses. These limits exclude at 95% confidence level models with Kaluza-Klein gluon masses in the range 2.0 to 4.3 TeV and radion masses in the range 0.20 to 0.74TeV. By exploring a novel experimental signature, the observed limits on the Kaluza-Klein gluon mass are extended by up to about 1 TeV compared to previous searches. (C) 2022 The Author(s). Published by Elsevier B.V.
  • Article
    Citation - WoS: 13
    Citation - Scopus: 15
    Strategies and Performance of the Cms Silicon Tracker Alignment During Lhc Run 2
    (Elsevier, 2022) Karapınar, Güler; CMS Collaboration
    The strategies for and the performance of the CMS silicon tracking system alignment during the 2015-2018 data-taking period of the LHC are described. The alignment procedures during and after data taking are explained. Alignment scenarios are also derived for use in the simulation of the detector response. Systematic effects, related to intrinsic symmetries of the alignment task or to external constraints, are discussed and illustrated for different scenarios.
  • Article
    Citation - WoS: 15
    Citation - Scopus: 20
    First Measurement of the Cross Section for Top Quark Pair Production With Additional Charm Jets Using Dileptonic Final States in Pp Collisions at Root S=13 Tev
    (Elsevier, 2021) Karapınar, Güler
    The first measurement of the inclusive cross section for top quark pairs (tt) produced in association with two additional charm jets is presented. The analysis uses the dileptonic final states of tt events produced in proton-proton collisions at a centre-of-mass energy of 13 TeV. The data correspond to an integrated luminosity of 41.5 fb-1, recorded by the CMS experiment at the LHC. A new charm jet identification algorithm provides input to a neural network that is trained to distinguish among tt events with two additional charm (ttcc), bottom (ttbb), and light-flavour or gluon (ttLL) jets. By means of a template fitting procedure, the inclusive ttcc, ttbb, and ttLL cross sections are simultaneously measured, together with their ratios to the inclusive tt + two jets cross section. This provides measurements of the ttcc and ttbb cross sections of 10.1 +/- 1.2 (stat) +/- 1.4 (syst) pb and 4.54 +/- 0.35 (stat) +/- 0.56 (syst) pb, respectively, in the full phase space. The results are compared and found to be consistent with predictions from two different matrix element generators with next-to-leading order accuracy in quantum chromodynamics, interfaced with a parton shower simulation. (c) 2021 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Funded by SCOAP3.
  • Article
    Citation - WoS: 19
    Citation - Scopus: 24
    Search for W ' Bosons Decaying To a Top and a Bottom Quark at Root S=13 Tev in the Hadronic Final State
    (Elsevier, 2021) Karapınar, Güler
    A search is performed for W ' bosons decaying to a top and a bottom quark in the all-hadronic final state, in proton-proton collisions at a center-of-mass energy of 13TeV. The analyzed data were collected by the CMS experiment between 2016 and 2018 and correspond to an integrated luminosity of 137fb(-1). Deep neural network algorithms are used to identify the jet initiated by the bottom quark and the jet containing the decay products of the top quark when the W ' boson from the top quark decays hadronically. No excess above the estimated standard model background is observed. Upper limits on the production cross sections of W ' bosons decaying to a top and a bottom quark are set. Both left- and right-handed W ' bosons with masses below 3.4TeV are excluded at 95% confidence level, and the most stringent limits to date on W ' bosons decaying to a top and a bottom quark in the all-hadronic final state are obtained. (C) 2021 The Author(s). Published by Elsevier B.V.
  • Article
    Citation - WoS: 29
    Citation - Scopus: 31
    Studies of Charm and Beauty Hadron Long-Range Correlations in Pp and Ppb Collisions at Lhc Energies
    (Elsevier, 2021) Karapınar, Güler
    Measurements of the second Fourier harmonic coefficient (v(2)) of the azimuthal distributions of prompt and nonprompt D-0 mesons produced in pp and pPb collisions are presented. Nonprompt D-0 mesons come from beauty hadron decays. The data samples are collected by the CMS experiment at nucleon-nucleon center-of-mass energies of 13 and 8.16 TeV, respectively. In high multiplicity pp collisions, v(2) signals for prompt charm hadrons are reported for the first time, and are found to be comparable to those for light-flavor hadron species over a transverse momentum (pT) range of 2-6 GeV. Compared at similar event multiplicities, the prompt D-0 meson v(2) values in pp and pPb collisions are similar in magnitude. The v(2) values for open beauty hadrons are extracted for the first time via nonprompt D-0 mesons in pPb collisions. For pT in the range of 2-5 GeV, the results suggest that v(2) for nonprompt D-0 mesons is smaller than that for prompt D-0 mesons. These new measurements indicate a positive charm hadron v(2) in pp collisions and suggest a mass dependence in v(2) between charm and beauty hadrons in the pPb system. These results provide insights into the origin of heavy-flavor quark collectivity in small systems. (C) 2020 The Author(s). Published by Elsevier B.V.
  • Article
    Citation - WoS: 21
    Citation - Scopus: 33
    Measurement of Prompt D-0 and D-0 Meson Azimuthal Anisotropy and Search for Strong Electric Fields in Pbpb Collisions at Root S-Nn=5.02 Tev
    (Elsevier, 2021) CMS Collaboration; Karapınar, Güler
    The strong Coulomb field created in ultrarelativistic heavy ion collisions is expected to produce a rapiditydependent difference (Av2) in the second Fourier coefficient of the azimuthal distribution (elliptic flow, v2) between D0 (uc) and D0 (uc) mesons. Motivated by the search for evidence of this field, the CMS detector at the LHC is used to perform the first measurement of Av2. The rapidity-averaged value is found to be (Av2) = 0.001 ? 0.001 (stat)? 0.003 (syst) in PbPb collisions at ?sNN = 5.02 TeV. In addition, the influence of the collision geometry is explored by measuring the D0 and D0mesons v2 and triangular flow coefficient (v3) as functions of rapidity, transverse momentum (pT), and event centrality (a measure of the overlap of the two Pb nuclei). A clear centrality dependence of prompt D0 meson v2 values is observed, while the v3 is largely independent of centrality. These trends are consistent with expectations of flow driven by the initial-state geometry. ? 2021 The Author. Published by Elsevier B.V. This is an open access article under the CC BY license
  • Article
    Citation - WoS: 56
    Citation - Scopus: 61
    First Measurement of Hadronic Event Shapes in Pp Collisions at S=7 Tev
    (Elsevier, 2011) Karapınar, Güler
    Hadronic event shapes have been measured in proton–proton collisions at s=7 TeV, with a data sample collected with the CMS detector at the LHC. The sample corresponds to an integrated luminosity of 3.2 pb?1. Event-shape distributions, corrected for detector response, are compared with five models of QCD multijet production. © 2011 CERN
  • Article
    Citation - WoS: 46
    Citation - Scopus: 46
    Measurement of the Zz Production Cross Section and Z -> L(+)l(-)l '(+)l '(-) Branching Fraction in Pp Collisions at Root S=13tev
    (Elsevier, 2016) Karapınar, Güler; CMS Collaboration
    Four-lepton production in proton-proton collisions, pp -> (Z/gamma*)(Z/gamma*)-> l(+)l(-)l '(+)l '(-), where l,l '(-) = e or mu, is studied at a center-of-mass energy of 13 TeV with the CMS detector at the LHC. The data sample corresponds to an integrated luminosity of 2.6fb(-1). The ZZ production cross section, sigma(pp -> ZZ) = 14.6(-1.8)(+1.9)(stat)(-0.3)(+0.5) (syst) +/-0.2 (theo) +/-0.4 (lumi) pb, is measured for events with two opposite-sign, sameflavor lepton pairs produced in the mass region 60 < m(l+l-) m (l'+l'-) < 120GeV. The Z boson branching fraction to four leptons is measured to be B(Z -> l(+)l(-)l '(+)l '(-)) = 4.9(-0.7)(+0.8)(stat)(-0.2)(+0.3)(syst)(-0.1)(+0.2)(theo) +/- 0.1 (lumi) x10(-6) for the four-lepton invariant mass in the range 80 < m(l+)l-l'+l' < 100GeVand dilepton mass m(l+l-) > 4GeVfor all opposite-sign, same-flavor lepton pairs. The results are in agreement with standard model predictions. (C) 2016 The Author. Published by Elsevier B. V. This is an open access article under the CC BY license
  • Article
    Citation - WoS: 7
    Citation - Scopus: 4
    Observation of the Decay B+ -> Psi(2s)phi(1020)k+ in Pp Collisions at Root S=8 Tev
    (Elsevier, 2017) Karapınar, Güler; CMS Collaboration
    The decay B+ -> psi(2S) phi(1020) K+ is observed for the first time using data collected from pp collisions at root S = 8 TeV by the CMS experiment at the LHC, corresponding to an integrated luminosity of 19.6 fb(-1). The branching fraction of this decay is measured, using the mode B+ -> psi(2S) K+ as normalization, to be (4.0 +/- 0.4 (stat)+/- 0.6 (syst)+/- 0.2 (B)) x 10(-6), where the third uncertainty is from the measured branching fraction of the normalization channel. (C) 2016 The Author(s). Published by Elsevier B.V.