WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7150
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Article Citation - WoS: 13Evidence for Ww/Wz Vector Boson Scattering in the Decay Channel <i>l</I>νqq Produced in Association With Two Jets in Proton-Proton Collisions at √<i>s</I>=13tev(Elsevier, 2022) Karapınar, Güler; CMS Collaboration; Andrejkovic, J. W.; Bergauer, T.; Chatterjee, S.; Dragicevic, M.; Vetens, W.Evidence is reported for electroweak (EW) vector boson scattering in the decay channel l nu qq of two weak vector bosons WV(V = Wor Z), produced in association with two parton jets. The search uses a data set of proton-proton collisions at 13TeVcollected with the CMS detector during 2016-2018 with an integrated luminosity of 138fb(-1). Events are selected requiring one lepton (electron or muon), moderate missing transverse momentum, two jets with a large pseudorapidity separation and a large dijet invariant mass, and a signature consistent with the hadronic decay of a W/Zboson. The cross section is computed in a fiducial phase space defined at parton level requiring all parton transverse momenta p(T)> 10 GeVand at least one pair of outgoing partons with invariant mass mqq> 100 GeV. The measured and expected EW WVproduction cross sections are 1.90(-0.46)(+0.5)3 pb and 2.23(-0.11)(+0.08)(scale) +/- 0.05(PDF) pb, respectively, where PDF is the parton distribution function. The observed EW signal strength is mu EW= 0.85 +/- 0.12 (stat)(-0.17)(+0.19)(syst), corresponding to a signal significance of 4.4 standard deviations with 5.1 expected, and it is measured keeping the quantum chromodynamics (QCD) associated diboson production fixed to the standard model prediction. This is the first evidence of vector boson scattering in the l nu qq decay channel at LHC. The simultaneous measurement of the EW and QCD associated diboson production agrees with the standard model prediction. (C) 2022 The Author(s). Published by Elsevier B.V.Article Citation - WoS: 1Citation - Scopus: 9Search for Heavy Resonances Decaying To Z (ν Ν ¯)v (q Q ¯ ′) in Proton-Proton Collisions at S =13 Tev(American Physical Society, 2022) Karapınar, Güler; CMS CollaborationA search is presented for heavy bosons decaying to Z(νν¯)V(qq¯′), where V can be a W or a Z boson. A sample of proton-proton collision data at s=13 TeV was collected by the CMS experiment during 2016-2018. The data correspond to an integrated luminosity of 137 fb-1. The event categorization is based on the presence of high-momentum jets in the forward region to identify production through weak vector boson fusion. Additional categorization uses jet substructure techniques and the presence of large missing transverse momentum to identify W and Z bosons decaying to quarks and neutrinos, respectively. The dominant standard model backgrounds are estimated using data taken from control regions. The results are interpreted in terms of radion, W′ boson, and graviton models, under the assumption that these bosons are produced via gluon-gluon fusion, Drell-Yan, or weak vector boson fusion processes. No evidence is found for physics beyond the standard model. Upper limits are set at 95% confidence level on various types of hypothetical new bosons. Observed (expected) exclusion limits on the masses of these bosons range from 1.2 to 4.0 (1.1 to 3.7) TeV. © 2022 CERN.Erratum Citation - WoS: 3Citation - Scopus: 7Searches for Long-Lived Charged Particles in Pp Collisions at Root S = 7 and 8 Tev (vol 07, 122, 2013)(Springer, 2022) Karapınar, Güler; CMS Collaboration[No abstract available]Article Citation - WoS: 28Citation - Scopus: 33Search for Low-Mass Dilepton Resonances in Higgs Boson Decays To Four-Lepton Final States in Proton-Proton Collisions at Root S=13 Tev(Springer, 2022) Karapınar, Güler; CMS CollaborationA search for low-mass dilepton resonances in Higgs boson decays is conducted in the four-lepton final state. The decay is assumed to proceed via a pair of beyond the standard model particles, or one such particle and a Z boson. The search uses proton-proton collision data collected with the CMS detector at the CERN LHC, corresponding to an integrated luminosity of 137 fb(-1), at a center-of-mass energy root s = 13 TeV. No significant deviation from the standard model expectation is observed. Upper limits at 95% confidence level are set on model-independent Higgs boson decay branching fractions. Additionally, limits on dark photon and axion-like particle production, based on two specific models, are reported.Article Citation - WoS: 13Citation - Scopus: 15Strategies and Performance of the Cms Silicon Tracker Alignment During Lhc Run 2(Elsevier, 2022) Karapınar, Güler; CMS CollaborationThe 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: 51Citation - Scopus: 28Search for Supersymmetry in Final States With Two or Three Soft Leptons and Missing Transverse Momentum in Proton-Proton Collisions at Root S=13 Tev(Springer, 2022) Karapınar, Güler; CMS CollaborationA search for supersymmetry in events with two or three low-momentum leptons and missing transverse momentum is performed. The search uses proton-proton collisions at root s = 13TeV collected in the three-year period 2016-2018 by the CMS experiment at the LHC and corresponding to an integrated luminosity of up to 137 fb(-1). The data are found to be in agreement with expectations from standard model processes. The results are interpreted in terms of electroweakino and top squark pair production with a small mass difference between the produced supersymmetric particles and the lightest neutralino. For the electroweakino interpretation, two simplified models are used, a wino-bino model and a higgsino model. Exclusion limits at 95% confidence level are set on (X) over tilde (0)(2) /(X) over tilde (+/-)(1) masses up to 275 GeV for a mass difference of 10 GeV in the wino-bino case, and up to 205(150) GeV for a mass difference of 7.5 (3) GeV in the higgsino case. The results for the higgsino are further interpreted using a phenomenological minimal supersymmetric standard model, excluding the higgsino mass parameter mu up to 180 GeV with the bino mass parameter M-1 at 800 GeV. In the top squark interpretation, exclusion limits are set at top squark masses up to 540 GeV for four-body top squark decays and up to 480 GeV for chargino-mediated decays with a mass difference of 30 GeV.Article Citation - WoS: 26Citation - Scopus: 38Search for Long-Lived Particles Decaying Into Muon Pairs in Proton-Proton Collisions at Root S=13 Tev Collected With a Dedicated High-Rate Data Stream(Springer, 2022) Karapınar, Güler; CMS CollaborationA search for long-lived particles decaying into muon pairs is performed using proton-proton collisions at a center-of-mass energy of 13 TeV, collected by the CMS experiment at the LHC in 2017 and 2018, corresponding to an integrated luminosity of 101 fb(-1). The data sets used in this search were collected with a dedicated dimuon trigger stream with low transverse momentum thresholds, recorded at high rate by retaining a reduced amount of information, in order to explore otherwise inaccessible phase space at low dimuon mass and nonzero displacement from the primary interaction vertex. No significant excess of events beyond the standard model expectation is found. Upper limits on branching fractions at 95% confidence level are set on a wide range of mass and lifetime hypotheses in beyond the standard model frameworks with the Higgs boson decaying into a pair of long-lived dark photons, or with a long-lived scalar resonance arising from a decay of a b hadron. The limits are the most stringent to date for substantial regions of the parameter space. These results can be also used to constrain models of displaced dimuons that are not explicitly considered in this paper.Article Citation - WoS: 12Citation - Scopus: 17Search for Long-Lived Particles Produced in Association With a Z Boson in Proton-Proton Collisions at Root S=13 Tev(Springer, 2022) Karapınar, Güler; CMS CollaborationA search for long-lived particles (LLPs) produced in association with a Z boson is presented. The study is performed using data from proton-proton collisions with a center-of-mass energy of 13 TeV recorded by the CMS experiment during 2016-2018, corresponding to an integrated luminosity of 117fb(-1).( )The LLPs are assumed to decay to a pair of standard model quarks that are identified as displaced jets within the CMS tracker system. Triggers and selections based on Z boson decays to electron or muon pairs improve the sensitivity to light LLPs (down to 15 GeV). This search provides sensitivity to beyond the standard model scenarios which predict LLPs produced in association with a Z boson. In particular, the results are interpreted in the context of exotic decays of the Higgs boson to a pair of scalar LLPs (H -> SS). The Higgs boson decay branching fraction is constrained to values less than 6% for proper decay lengths of 10-100 mm and for LLP masses between 40 and 55 GeV. In the case of low-mass (approximate to 15 GeV) scalar particles that subsequently decay to a pair of b quarks, the search is sensitive to branching fractions B(H -> SS) < 20% for proper decay lengths of 10-50 mm. The use of associated production with a Z boson increases the sensitivity to low-mass LLPs of this analysis with respect to gluon fusion searches. In the case of 15 GeV scalar LLPs, the improvement corresponds to a factor of 2 at a proper decay length of 30 mm.Article Citation - WoS: 5Citation - Scopus: 10Study of Dijet Events With Large Rapidity Separation in Proton-Proton Collisions at Root S=2.76 Tev(Springer, 2022) Karapınar, Güler; CMS CollaborationThe cross sections for inclusive and Mueller-Navelet dijet production are measured as a function of the rapidity separation between the jets in proton-proton collisions at root s = 2.76 TeV for jets with transverse momentum p(T) > 35 GeV and rapidity vertical bar y vertical bar < 4.7. Various dijet production cross section ratios are also measured. A veto on additional jets with p(T) > 20 GeV is introduced to improve the sensitivity to the effects of the Balitsky-Fadin-Kuraev-Lipatov (BFKL) evolution. The measurement is compared with the predictions of various Monte Carlo models based on leading-order and next-to-leading-order calculations including the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi leading-logarithm (LL) parton shower as well as the LL BFKL resummation.Article Citation - WoS: 44Citation - Scopus: 34Study of Quark and Gluon Jet Substructure in Z Plus Jet and Dijet Events From Pp Collisions(Springer, 2022) Karapınar, Güler; CMS CollaborationMeasurements of jet substructure describing the composition of quark- and gluon-initiated jets are presented. Proton-proton (pp) collision data at root s = 13 TeV collected with the CMS detector are used, corresponding to an integrated luminosity of 35.9 fb(-1). Generalized angularities are measured that characterize the jet substructure and distinguish quark- and gluon-initiated jets. These observables are sensitive to the distributions of transverse momenta and angular distances within a jet. The analysis is performed using a data sample of dijet events enriched in gluon-initiated jets, and, for the first time, a Z+jet event sample enriched in quark-initiated jets. The observables are measured in bins of jet transverse momentum, and as a function of the jet radius parameter. Each measurement is repeated applying a soft drop grooming procedure that removes soft and large angle radiation from the jet. Using these measurements, the ability of various models to describe jet substructure is assessed, showing a clear need for improvements in Monte Carlo generators.