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Search for microscopic black hole signatures at the Large Hadron Collider
(2011)Physics Letters BA search for microscopic black hole production and decay in pp collisions at a center-of-mass energy of 7 TeV has been conducted by the CMS Collaboration at the LHC, using a data sample corresponding to an integrated luminosity of 35 pb−1. Events with large total transverse energy are analyzed for the presence of multiple high-energy jets, leptons, and photons, typical of a signal expected from a microscopic black hole. Good agreement ...Journal Article -
Prompt and non-prompt J/ψ production in pp collisions at √s=7 TeV
(2011)The European Physical Journal CThe production of J/ψ mesons is studied in pp collisions at s√=7 TeV with the CMS experiment at the LHC. The measurement is based on a dimuon sample corresponding to an integrated luminosity of 314 nb−1. The J/ψ differential cross section is determined, as a function of the J/ψ transverse momentum, in three rapidity ranges. A fit to the decay length distribution is used to separate the prompt from the non-prompt (b hadron to J/ψ) component. ...Journal Article -
Study of Z Boson Production in PbPb Collisions at √sNN=2.76 TeV
(2011)Physical Review LettersA search for Z bosons in the μ+μ− decay channel has been performed in PbPb collisions at √sNN=2.76 TeV with the CMS detector at the LHC, in a 7.2 μb−1 data sample. The number of opposite-sign muon pairs observed in the 60–120 GeV/c2 invariant mass range is 39, corresponding to a yield per unit of rapidity (y) and per minimum bias event of [33.8±5.5(stat)±4.4(syst)]×10−8, in the |y|<2.0 range. Rapidity, transverse momentum, and centrality ...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 production cross section in pp collisions at √s = 7 TeV using the kinematic properties of events with leptons and jets
(2011)The European Physical Journal CA measurement of the tt¯ production cross section in proton-proton collisions at a centre-of-mass energy of 7 TeV has been performed at the LHC with the CMS detector. The analysis uses a data sample corresponding to an integrated luminosity of 36 pb−1 and is based on the reconstruction of the final state with one isolated, high transverse-momentum electron or muon and three or more hadronic jets. The kinematic properties of the events are ...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 two photons and missing transverse energy
(2011)Physical Review LettersA search for supersymmetry in the context of general gauge-mediated breaking with the lightest neutralino as the next-to-lightest supersymmetric particle and the gravitino as the lightest is presented. The data sample corresponds to an integrated luminosity of 36 pb−1 recorded by the CMS experiment at the LHC. The search is performed by using events containing two or more isolated photons, at least one hadronic jet, and significant missing ...Journal Article -
Search for new physics with same-sign isolated dilepton events with jets and missing transverse energy at the LHC
(2011)Journal of High Energy PhysicsThe results of searches for new physics in events with two same-sign isolated leptons, hadronic jets, and missing transverse energy in the final state are presented. The searches use an integrated luminosity of 35 pb−1 of pp collision data at a centre-of-mass energy of 7 TeV collected by the CMS experiment at the LHC. The observed numbers of events agree with the standard model predictions, and no evidence for new physics is found. To ...Journal Article -
Determination of Jet Energy Calibration and Transverse Momentum Resolution in CMS
(2011)Journal of InstrumentationMeasurements of the jet energy calibration and transverse momentum resolution in CMS are presented, performed with a data sample collected in proton-proton collisions at a centre-of-mass energy of 7TeV, corresponding to an integrated luminosity of 36pb−1. The transverse momentum balance in dijet and γ/Z+jets events is used to measure the jet energy response in the CMS detector, as well as the transverse momentum resolution. The results ...Journal Article -
Measurement of the lepton charge asymmetry in inclusive W production in pp collisions at root √s=7 TeV
(2011)Journal of High Energy PhysicsA measurement of the lepton charge asymmetry in inclusive pp → WX production at s√=7TeV is presented based on data recorded by the CMS detector at the LHC and corresponding to an integrated luminosity of 36 pb−1. This high precision measurement of the lepton charge asymmetry, performed in both the W → eν and W → μν channels, provides new insights into parton distribution functions.Journal Article