Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Citation - WoS: 28Citation - Scopus: 26Investigation Into the Event-Activity Dependence of Gamma(ns) Relative Production in Proton-Proton Collisions at Root S=7 Tev(Springer Verlag, 2020) Karapınar, Güler; CMS CollaborationThe ratios of the production cross sections between the excited gamma(2S) and gamma(3S) mesons and the gamma(1S) ground state, detected via their decay into two muons, are studied as a function of the number of charged particles in the event. The data are from proton-proton collisions at root s = 7TeV, corresponding to an integrated luminosity of 4.8 fb(-1), collected with the CMS detector at the LHC. Evidence of a decrease in these ratios as a function of the particle multiplicity is observed, more pronounced at low transverse momentum p(T)(mu mu). For gamma(nS) mesons with p(T)(mu mu) > 7 GeV, where most of the data were collected, the correlation with multiplicity is studied as a function of the underlying event transverse sphericity and the number of particles in a cone around the gamma(nS) direction. The ratios are found to be multiplicity independent for jet-like events. The mean p(T)(mu mu) values for the gamma(nS) states as a function of particle multiplicity are also measured and found to grow more steeply as their mass increases.Article Citation - WoS: 1Citation - Scopus: 10Study of the B+ -> J/Psi(lambda)over-barp Decay in Proton-Proton Collisions at Root S=8 Tev(Springer Verlag, 2019) Karapınar, Güler; CMS CollaborationA study of the B+-> J/psi = 8 TeV by the CMS experiment at the LHC, corresponding to an integrated luminosity of 19.6 fb(-1), is presented. The ratio of branching fractions B+-> J/psi B+-> J/psi K is measured to be (1.054 +/- 0.057(stat) +/- 0.035(syst) +/- 0.011 where the last uncertainty reflects the uncertainties in the world-average branching fractions of and K*(892) (+) decays to reconstructed final states. The invariant mass distributions of the J/psi, J/psi systems produced in the B+-> J/psi decay are investigated and found to be inconsistent with the pure phase space hypothesis. The analysis is extended by using a model-independent angular amplitude analysis, which shows that the observed invariant mass distributions are consistent with the contributions from excited kaons decaying to the (Lambda) over barp system.Article Citation - WoS: 72Citation - Scopus: 85Measurement of Properties of B(s)(0)s -> Mu(+)mu(-) Decays and Search for B-0 -> Mu(+)mu(-) With the Cms Experiment(Springer Verlag, 2020) Karapınar, Güler; CMS CollaborationResults are reported for the B 0s ! + branching fraction and effective lifetime and from a search for the decay B0 ! + . The analysis uses a data sample of proton-proton collisions accumulated by the CMS experiment in 2011, 2012, and 2016, with center-of-mass energies (integrated luminosities) of 7TeV (5 fb), 8TeV (20 fb), and 13TeV (36 fb). The branching fractions are determined by measuring event yields relative to B+ ! J= K+ decays (with J= ! + ), which results in the reduction of many of the systematic uncertainties. The decay B 0s ! + is observed with a significance of 5.6 standard deviations. The branching fraction is measured to be B (B 0s ! + ) = [2:9 0:7(exp) 0:2(frag)] 10, where the first uncertainty combines the experimental statistical and systematic contributions, and the second is due to the uncertainty in the ratio of the B 0s and the B+ fragmentation functions. No significant excess is observed for the decay B0 ! + , and an upper limit of B(B0 ! + ) < 3:6 10 is obtained at 95% confidence level. The B 0s ! + effective lifetime is measured to be + = 1:70 +0:61 ps. These results are consistent with standard model predictions.