Search
Results
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Dependence on pseudorapidity and on centrality of charged hadron production in PbPb collisions at √sNN=2.76 TeV
(2011)Journal of High Energy PhysicsA measurement is presented of the charged hadron multiplicity in hadronic PbPb collisions, as a function of pseudorapidity and centrality, at a collision energy of 2.76 TeV per nucleon pair. The data sample is collected using the CMS detector and a minimum-bias trigger, with the CMS solenoid off. The number of charged hadrons is measured both by counting the number of reconstructed particle hits and by forming hit doublets of pairs of ...Journal Article -
Measurement of the t-Channel Single Top Quark Production Cross Section in pp Collisions at √s=7 TeV
(2011)Physical Review LettersElectroweak production of the top quark is measured for the first time in pp collisions at √s=7 TeV, using a data set collected with the CMS detector at the LHC and corresponding to an integrated luminosity of 36 pb−1. With an event selection optimized for t-channel production, two complementary analyses are performed. The first one exploits the special angular properties of the signal, together with background estimates from the data. ...Journal Article -
Indications of Suppression of Excited Upsilon States in Pb-Pb Collisions at root(s)NN=2.76 TeV
(2011)Physical Review LettersA comparison of the relative yields of Υ resonances in the μ+μ− decay channel in Pb-Pb and pp collisions at a center-of-mass energy per nucleon pair of 2.76 TeV is performed with data collected with the CMS detector at the LHC. Using muons of transverse momentum above 4 GeV/c and pseudorapidity below 2.4, the double ratio of the Υ(2S) and Υ(3S) excited states to the Υ(1S) ground state in Pb-Pb and pp collisions, [Υ(2S+3S)/Υ(1S)]Pb−Pb/[ ...Journal Article -
Measurement of the t(t)over-bar production cross section and the top quark mass in the dilepton channel in pp collisions at root s=7 Tev
(2011)Journal of High Energy PhysicsThe tt¯ production cross section and top quark mass are measured in proton-proton collisions at s√=7 TeV in a data sample corresponding to an integrated luminosity of 36 pb−1 collected by the CMS experiment. The measurements are performed in events with two leptons (electrons or muons) in the final state. Results of the cross section measurement in events with and without b-quark identification are obtained and combined. The measured value ...Journal Article -
Search for supersymmetry in events with a lepton, a photon, and large missing transverse energy in pp collisions at root s=7 TeV
(2011)Journal of High Energy PhysicsA search is performed for an excess of events, over the standard model expectations, with a photon, a lepton, and large missing transverse energy in pp collisions at s√=7 TeV. Such events are expected in many new physics models, in particular a supersymmetric theory that is broken via a gauge-mediated mechanism, when the lightest charged and neutral gauginos are mass degenerate. The data sample used in this search corresponds to an ...Journal Article -
Search for supersymmetry in pp collisions at √s=7 TeV in events with a single lepton, jets, and missing transverse momentum
(2011)Journal of High Energy PhysicsResults are reported from a search for physics beyond the standard model in proton-proton collisions at a center-of-mass energy of 7 TeV, focusing on the signature with a single, isolated, high-transverse-momentum lepton (electron or muon), energetic jets, and large missing transverse momentum. The data sample comprises an integrated luminosity of 36 pb−1, recorded by the CMS experiment at the LHC. The search is motivated by models of new ...Journal Article