WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7150
Browse
5 results
Search Results
Now showing 1 - 5 of 5
Article Citation - WoS: 52Citation - Scopus: 56Study of Jet Quenching With Isolated-Photon+jet Correlations in Pbpb and Pp Collisions at Snn=5.02 Tev(Elsevier Ltd., 2018) CMS Collaboration; Karapınar, GülerMeasurements of azimuthal angle and transverse momentum (pT) correlations of isolated photons and associated jets are reported for pp and PbPb collisions at sNN=5.02 TeV. The data were recorded with the CMS detector at the CERN LHC. For events containing a leading isolated photon with pT γ>40 GeV/c and an associated jet with pT jet>30 GeV/c, the photon+jet azimuthal correlation and pT imbalance in PbPb collisions are studied as functions of collision centrality and pT γ. The results are compared to pp reference data collected at the same collision energy and to predictions from several theoretical models for parton energy loss. No evidence of broadening of the photon+jet azimuthal correlations is observed, while the ratio pT jet/pT γ decreases significantly for PbPb data relative to the pp reference. All models considered agree within uncertainties with the data. The number of associated jets per photon with pT γ>80 GeV/c is observed to be shifted towards lower pT jet values in central PbPb collisions compared to pp collisions.Article Citation - WoS: 11Citation - Scopus: 11Search for Excited Quarks of Light and Heavy Flavor in ? +jet Final States in Proton–proton Collisions at S=13tev(Elsevier Ltd., 2018) CMS Collaboration; Karapınar, GülerA search is presented for excited quarks of light and heavy flavor that decay to γ+jet final states. The analysis is based on data corresponding to an integrated luminosity of 35.9fb−1 collected by the CMS experiment in proton–proton collisions at s=13TeV at the LHC. A signal would appear as a resonant contribution to the invariant mass spectrum of the γ+jet system, above the background expected from standard model processes. No resonant excess is found, and upper limits are set on the product of the excited quark cross section and its branching fraction as a function of its mass. These are the most stringent limits to date in the γ+jet final state, and exclude excited light quarks with masses below 5.5 TeV and excited b quarks with masses below 1.8 TeV, assuming standard model like coupling strengths.Article Citation - WoS: 144Citation - Scopus: 121Inclusive Search for a Vector-Like T Quark With Charge 2/3 in Pp Collisions at ?s=8 Tev(Elsevier Ltd., 2014) CMS Collaboration; Karapınar, GülerA search is performed for a massive new vector-like quark T, with charge 23, that is pair produced together with its antiparticle in proton-proton collisions. The data were collected by the CMS experiment at the Large Hadron Collider in 2012 at s=8TeV and correspond to an integrated luminosity of 19.5fb-1. The T quark is assumed to decay into three different final states, bW, tZ, and tH. The search is carried out using events with at least one isolated lepton. No deviations from standard model expectations are observed, and lower limits are set on the T quark mass at 95% confidence level. The lower limit lies between 687 and 782 GeV for all possible values of the branching fractions into the three different final states assuming strong production. These limits are the most stringent constraints to date on the existence of such a quark. © 2014 The Authors.Article Citation - WoS: 63Citation - Scopus: 51Search for Top-Squark Pairs Decaying Into Higgs or Z Bosons in Pp Collisions at S=8 Tev(Elsevier Ltd., 2014) CMS Collaboration; Karapınar, GülerA search for supersymmetry through the direct pair production of top squarks, with Higgs (H) or Z bosons in the decay chain, is performed using a data sample of proton-proton collisions at s=8 TeV collected in 2012 with the CMS detector at the LHC. The sample corresponds to an integrated luminosity of 19.5 fb-1. The search is performed using a selection of events containing leptons and bottom-quark jets. No evidence for a significant excess of events over the standard model background prediction is observed. The results are interpreted in the context of simplified supersymmetric models with pair production of a heavier top-squark mass eigenstate t~2 decaying to a lighter top-squark mass eigenstate t~1 via either t~2→Ht~1 or t~2→Zt~1, followed in both cases by t~1→tχ~10, where χ~10 is an undetected, stable, lightest supersymmetric particle. The interpretation is performed in the region where the mass difference between the t~1 and χ~10 states is approximately equal to the top-quark mass (mt~1-mχ~10≃mt), which is not probed by searches for direct t~1 squark pair production. The analysis excludes top squarks with masses mt~2<575 GeV and mt~1<400 GeV at a 95% confidence level. © 2014 The Authors.Article Citation - WoS: 198Citation - Scopus: 210Physical and Chemical Interactions in Coal Flotation(Elsevier Ltd., 2003) Polat, Mehmet; Polat, Hürriyet; Chander, SubhashCoal flotation is a complex process involving several phases (particles, oil droplets and air bubbles). These phases simultaneously interact with each other and with other species such as the molecules of a promoting reagent and dissolved ions in water. The physical and chemical interactions determine the outcome of the flotation process. Physical and chemical interactions between fine coal particles could lead to aggregation, especially for high rank coals. Non-selective particle aggregation could be said to be the main reason for the selectivity problems in coal flotation. It should be addressed by physical (conditioning) or chemical (promoters) pretreatment before or during flotation. Although the interactions between the oil droplets and coal particles are actually favored, stabilization of the oil droplets by small amounts of fine hydrophobic particles may lead to a decrease in selectivity and an increase in oil consumption. These problems could be remedied by use of promoters that modify the coal surface for suitable particle-particle, droplet-particle and particle-bubble contact while emulsifying the oil droplets. The role of promoters may be different for different types of coals, however. They could be employed as modifiers to increase the hydrophobicity of low rank coals whereas their main role might be emulsification and aggregation control for high rank coals. In this paper, a detailed description of the various phases in coal flotation, their physical and chemical interactions with each other in the flotation pulp, the major parameters that affect these interactions and how these interactions, in turn, influence the flotation process are discussed.