Rectorate / Rektörlük

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

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  • Article
    Citation - WoS: 208
    Citation - Scopus: 186
    Performance of Photon Reconstruction and Identification With the Cms Detector in Proton-Proton Collisions at ?s = 8 Tev
    (IOP Publishing Ltd., 2015) CMS Collaboration; Karapınar, Güler
    A description is provided of the performance of the CMS detector for photon reconstruction and identification in proton-proton collisions at a centre-of-mass energy of 8 TeV at the CERN LHC. Details are given on the reconstruction of photons from energy deposits in the electromagnetic calorimeter (ECAL) and the extraction of photon energy estimates. The reconstruction of electron tracks from photons that convert to electrons in the CMS tracker is also described, as is the optimization of the photon energy reconstruction and its accurate modelling in simulation, in the analysis of the Higgs boson decay into two photons. In the barrel section of the ECAL, an energy resolution of about 1% is achieved for unconverted or late-converting photons from Hγγ decays. Different photon identification methods are discussed and their corresponding selection efficiencies in data are compared with those found in simulated events. © CERN 2015 for the benefit of the CMS collaboration.
  • Article
    Citation - WoS: 453
    Citation - Scopus: 360
    Identification of B-Quark Jets With the Cms Experiment
    (IOP Publishing Ltd., 2013) CMS Collaboration; Karapınar, Güler
    At the Large Hadron Collider, the identification of jets originating from b quarks is important for searches for new physics and for measurements of standard model processes. A variety of algorithms has been developed by CMS to select b-quark jets based on variables such as the impact parameters of charged-particle tracks, the properties of reconstructed decay vertices, and the presence or absence of a lepton, or combinations thereof. The performance of these algorithms has been measured using data from proton-proton collisions at the LHC and compared with expectations based on simulation. The data used in this study were recorded in 2011 at s = 7 TeV for a total integrated luminosity of 5.0 fb-1. The efficiency for tagging b-quark jets has been measured in events from multijet and t-quark pair production. CMS has achieved a b-jet tagging efficiency of 85% for a light-parton misidentification probability of 10% in multijet events. For analyses requiring higher purity, a misidentification probability of only 1.5% has been achieved, for a 70% b-jet tagging efficiency. © 2013 IOP Publishing Ltd and Sissa Medialab srl.