Rectorate / Rektörlük

Permanent URI for this collectionhttps://hdl.handle.net/11147/6849

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  • Article
    Citation - WoS: 3
    Citation - Scopus: 3
    Selfless Subjectivities That (re)build the Nation: Remaking the Modern Turkish Woman in the Early Republican Period in Turkiye
    (SAGE Publications, 2023) Yakalı, Dikmen; Ataman, Bora
    This study explores the newly constructed female identities of the Early Republican Era in Turkiye (1923-1945). Through a thematic analysis of three contemporary women's magazines (Aile Dostu, Ev-Is, and Asrin Kadini) it aims to examine how conceptualizations of marriage and family were refashioned in the magazines to fit in the images within the newly constructed domestic ideologies of the state. We argue that the selfless subjectivities offered by the magazines point to dialogically constructed narrative identities which are not stable but fluid. The women's magazines of the Era aimed to reconstruct new identities by representing the Republic's ideas and official ideology to its people. Thus, they became one of the tools of social engineering in the way of transforming the nation into a modern, Westernized one. Analysing these magazines help us identify the repertoire of subjectivities and narrative identities from which women drew while making sense of their selves during an era of transformation.
  • Article
    Product Design in Monopolistic Competition
    (Wiley, 2022) Dindaroğlu, Burak
    We consider a model of monopolistic competition where producers can manipulate an elasticity parameter at an early stage. We interpret this as a choice of product specialization. Lower marginal costs of production lead to more generic products in all equilibria, which lead to fewer varieties under free-entry. Entry of a new firm increases overall specialization and increases prices, that is, the environment exhibits price-increasing competition. The loss of consumer surplus due to higher prices and lower consumption is compensated by the value of additional variety, hence entry also increases consumer surplus. Therefore, price-increasing competition need not be anticompetitive under endogenous specialization.
  • Article
    Citation - WoS: 19
    Citation - Scopus: 15
    A New Calibration Method for Charm Jet Identification Validated With Proton-Proton Collision Events at Root S=13 Tev
    (IOP Publishing Ltd, 2022) Tumasyan, A.; Karapınar, Güler
    Many measurements at the LHC require efficient identification of heavy-flavour jets, i.e. jets originating from bottom (b) or charm (c) quarks. An overview of the algorithms used to identify c jets is described and a novel method to calibrate them is presented. This new method adjusts the entire distributions of the outputs obtained when the algorithms are applied to jets of different flavours. It is based on an iterative approach exploiting three distinct control regions that are enriched with either b jets, c jets, or light-flavour and gluon jets. Results are presented in the form of correction factors evaluated using proton-proton collision data with an integrated luminosity of 41.5 fb(-1) at root s = 13 TeV, collected by the CMS experiment in 2017. The closure of the method is tested by applying the measured correction factors on simulated data sets and checking the agreement between the adjusted simulation and collision data. Furthermore, a validation is performed by testing the method on pseudodata, which emulate various mismodelling conditions. The calibrated results enable the use of the full distributions of heavy-flavour identification algorithm outputs, e.g. as inputs to machine-learning models. Thus, they are expected to increase the sensitivity of future physics analyses.
  • Article
    Citation - WoS: 51
    Citation - Scopus: 60
    Identification of Hadronic Tau Lepton Decays Using a Deep Neural Network
    (Institute of Physics, 2022) Tumasyan, A.; Adam, W.; Andrejkovic, J.W.; Bergauer, T.; Chatterjee, S.; Dragicevic, M.; Andreev, V.
    A new algorithm is presented to discriminate reconstructed hadronic decays of tau leptons (τ h) that originate from genuine tau leptons in the CMS detector against τ h candidates that originate from quark or gluon jets, electrons, or muons. The algorithm inputs information from all reconstructed particles in the vicinity of a τ h candidate and employs a deep neural network with convolutional layers to efficiently process the inputs. This algorithm leads to a significantly improved performance compared with the previously used one. For example, the efficiency for a genuine τ h to pass the discriminator against jets increases by 10-30% for a given efficiency for quark and gluon jets. Furthermore, a more efficient τ h reconstruction is introduced that incorporates additional hadronic decay modes. The superior performance of the new algorithm to discriminate against jets, electrons, and muons and the improved τ h reconstruction method are validated with LHC proton-proton collision data at s = 13 TeV. © 2022 CERN.
  • 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: 198
    Citation - Scopus: 229
    Electron and Photon Reconstruction and Identification With the Cms Experiment at the Cern Lhc
    (IOP Publishing, 2021) Karapınar, Güler; CMS Collaboration
    The performance is presented of the reconstruction and identification algorithms for electrons and photons with the CMS experiment at the LHC. The reported results are based on proton-proton collision data collected at a center-of-mass energy of 13 TeV and recorded in 2016-2018, corresponding to an integrated luminosity of 136 fb(-1). Results obtained from lead-lead collision data collected at root S-NN = 5.02 TeV are also presented. Innovative techniques are used to reconstruct the electron and photon signals in the detector and to optimize the energy resolution. Events with electrons and photons in the final state are used to measure the energy resolution and energy scale uncertainty in the recorded events. The measured energy resolution for electrons produced in Z boson decays in proton-proton collision data ranges from 2 to 5%, depending on electron pseudorapidity and energy loss through bremsstrahlung in the detector material. The energy scale in the same range of energies is measured with an uncertainty smaller than 0.1 (0.3)% in the barrel (endcap) region in proton-proton collisions and better than 1(3)% in the barrel (endcap) region in heavy ion collisions. The timing resolution for electrons from Z boson decays with the full 2016-2018 proton-proton collision data set is measured to be 200 ps.
  • Article
    Citation - WoS: 239
    Citation - Scopus: 291
    Performance of the Cms Level-1 Trigger in Proton-Proton Collisions at √s = 13 Tev
    (Institute of Physics, 2020) Sirunyan, A.M.; Tumasyan, A.; Adam, W.; Bergauer, T.; Dragicevic, M.; Erö, J.; Bunichev, V.
    At the start of Run 2 in 2015, the LHC delivered proton-proton collisions at a center-of-mass energy of 13 TeV. During Run 2 (years 2015-2018) the LHC eventually reached a luminosity of 2.1 × 1034 cm-2s-1, almost three times that reached during Run 1 (2009-2013) and a factor of two larger than the LHC design value, leading to events with up to a mean of about 50 simultaneous inelastic proton-proton collisions per bunch crossing (pileup). The CMS Level-1 trigger was upgraded prior to 2016 to improve the selection of physics events in the challenging conditions posed by the second run of the LHC. This paper describes the performance of the CMS Level-1 trigger upgrade during the data taking period of 2016-2018. The upgraded trigger implements pattern recognition and boosted decision tree regression techniques for muon reconstruction, includes pileup subtraction for jets and energy sums, and incorporates pileup-dependent isolation requirements for electrons and tau leptons. In addition, the new trigger calculates high-level quantities such as the invariant mass of pairs of reconstructed particles. The upgrade reduces the trigger rate from background processes and improves the trigger efficiency for a wide variety of physics signals. © 2020 CERN for the benefit of the CMS collaboration.
  • Article
    Citation - WoS: 11
    Citation - Scopus: 13
    The Very Forward Castor Calorimeter of the Cms Experiment
    (Institute of Physics, 2021) Khachatryan,V.; Sirunyan,A.M.; Tumasyan,A.; Adam,W.; Ambrogi,F.; Bergauer,T.; Smirnov,I.
    The physics motivation, detector design, triggers, calibration, alignment, simulation, and overall performance of the very forward CASTOR calorimeter of the CMS experiment are reviewed. The CASTOR Cherenkov sampling calorimeter is located very close to the LHC beam line, at a radial distance of about 1cm from the beam pipe, and at 14.4m from the CMS interaction point, covering the pseudorapidity range of -6.6 < η < -5.2. It was designed to withstand high ambient radiation and strong magnetic fields. The performance of the detector in measurements of forward energy density, jets, and processes characterized by rapidity gaps, is reviewed using data collected in proton and nuclear collisions at the LHC. © 2021 CERN for the benefit of the CMS collaboration..
  • Article
    Citation - WoS: 5
    Citation - Scopus: 32
    Performance of the Cms Muon Trigger System in Proton-Proton Collisions at ?s = 13 Tev
    (IOP Publishing Ltd, 2021) CMS Collaboration; Karapınar, Güler
    The muon trigger system of the CMS experiment uses a combination of hardware and software to identify events containing a muon. During Run 2 (covering 2015-2018) the LHC achieved instantaneous luminosities as high as 2 × 10 cm s while delivering proton-proton collisions at ?s = 13 TeV. The challenge for the trigger system of the CMS experiment is to reduce the registered event rate from about 40 MHz to about 1 kHz. Significant improvements important for the success of the CMS physics program have been made to the muon trigger system via improved muon reconstruction and identification algorithms since the end of Run 1 and throughout the Run 2 data-taking period. The new algorithms maintain the acceptance of the muon triggers at the same or even lower rate throughout the data-taking period despite the increasing number of additional proton-proton interactions in each LHC bunch crossing. In this paper, the algorithms used in 2015 and 2016 and their improvements throughout 2017 and 2018 are described. Measurements of the CMS muon trigger performance for this data-taking period are presented, including efficiencies, transverse momentum resolution, trigger rates, and the purity of the selected muon sample. This paper focuses on the single- and double-muon triggers with the lowest sustainable transverse momentum thresholds used by CMS. The efficiency is measured in a transverse momentum range from 8 to several hundred GeV. © 2021 CERN for the benefit of the CMS collaboration.
  • Article
    Citation - WoS: 31
    Citation - Scopus: 65
    The Performance of the Cms Muon Detector in Proton-Proton Collisions at Root S=7 Tev at the Lhc
    (IOP Publishing Ltd., 2013) Karapınar, Güler
    The performance of all subsystems of the CMS muon detector has been studied by using a sample of proton-proton collision data at root s = 7TeV collected at the LHC in 2010 that corresponds to an integrated luminosity of approximately 40 pb(-1). The measured distributions of the major operational parameters of the drift tube (DT), cathode strip chamber (CSC), and resistive plate chamber (RPC) systems met the design specifications. The spatial resolution per chamber was 80-120 mu m in the DTs, 40-150 mu m in the CSCs, and 0.8-1.2 cm in the RPCs. The time resolution achievable was 3 ns or better per chamber for all 3 systems. The efficiency for reconstructing hits and track segments originating from muons traversing the muon chambers was in the range 95-98%. The CSC and DT systems provided muon track segments for the CMS trigger with over 96% efficiency, and identified the correct triggering bunch crossing in over 99.5% of such events. The measured performance is well reproduced by Monte Carlo simulation of the muon system down to the level of individual channel response. The results confirm the high efficiency of the muon system, the robustness of the design against hardware failures, and its effectiveness in the discrimination of backgrounds.