54 research outputs found

    Measurement of the mass difference between top quark and antiquark in pp collisions at root s=8 TeV

    Get PDF
    Peer reviewe

    Studies of azimuthal dihadron correlations in ultra-central PbPb collisions at=2.76 TeV

    Get PDF

    Observation of a peaking structure in the J/psi phi mass spectrum from B(+/-) to J/psi phi K(+/-) decays

    Get PDF

    Measurement of the production cross section for a W boson and two b jets in pp collisions at root s=7 TeV

    Get PDF
    The production cross section for a W boson and two b jets is measured using proton&#8211;proton collisions at s=7 TeV in a data sample collected with the CMS experiment at the LHC corresponding to an integrated luminosity of 5.0 fb &#8722;1 . The W+bb¯ events are selected in the W&#8594;&#956;&#957; decay mode by requiring a muon with transverse momentum pT>25 GeV and pseudorapidity |&#951;|25 GeV and |&#951;|<2.4 . The measured W+bb¯ production cross section in the fiducial region, calculated at the level of final-state particles, is &#963;(pp&#8594;W+bb¯)×B(W&#8594;&#956;&#957;)=0.53±0.05(stat.)±0.09(syst.)±0.06(theo.)±0.01(lum.) pb , in agreement with the standard model prediction. In addition, kinematic distributions of the W+bb¯ system are in agreement with the predictions of a simulation using MadGraph and pythia

    Measurements of the t(t)Overbar charge asymmetry using the dilepton decay channel in pp collisions at root s=7 TeV

    Get PDF
    The tt¯ charge asymmetry in proton-proton collisions at s&#8730; = 7 TeV is measured using the dilepton decay channel (ee, e &#956; , or &#956;&#956; ). The data correspond to a total integrated luminosity of 5.0 fb &#8722;1 , collected by the CMS experiment at the LHC. The tt and lepton charge asymmetries, defined as the differences in absolute values of the rapidities between the reconstructed top quarks and antiquarks and of the pseudorapidities between the positive and negative leptons, respectively, are measured to be A C = &#8722;0 . 010 ± 0 . 017 (stat . ) ± 0 . 008 (syst . ) and AlepC = 0 . 009 ± 0 . 010 (stat . ) ± 0 . 006 (syst . ). The lepton charge asymmetry is also measured as a function of the invariant mass, rapidity, and transverse momentum of the tt¯ system. All measurements are consistent with the expectations of the standard model

    Measurement of the top-quark mass in all-jets tt events in pp collisions at root = 7 TeV

    Get PDF
    The mass of the top quark is measured using a sample of tt¯ candidate events with at least six jets in the final state. The sample is selected from data collected with the CMS detector in pp collisions at s&#8730;=7 TeV in 2011 and corresponds to an integrated luminosity of 3.54 fb&#8722;1 . The mass is reconstructed for each event employing a kinematic fit of the jets to a tt¯ hypothesis. The top-quark mass is measured to be 173.49±0.69(stat.)±1.21(syst.) GeV. A combination with previously published measurements in other decay modes by CMS yields a mass of 173.54±0.33(stat.)±0.96(syst.) GeV

    Searches for light- and heavy-flavour three-jet resonances in pp collisions at root s=8 TeV

    Get PDF

    Reduction, analysis and application of one‐way laser ranging data from ILRS ground station to LRO

    Get PDF
    One-way laser ranging is being performed routinely from International Laser Ranging Service ground stations to the Lunar Orbiter Laser Altimeter, an instrument onboard NASA’s Lunar Reconnaissance Orbiter. We developed software to process this novel type of tracking data and gathered information e.g. on characteristics and distribution in a preliminary analysis. By incorporating the high accuracy spacecraft range measurements into orbit determination, one expects the positioning and thereby the accuracy of further derived data products to improve. We used the one-way laser ranging measurements within an estimation software based on the Tudat library for carrying out an orbit determination for the Lunar Reconnaissance Orbiter. Thereby the results from the preliminary analysis on tracking data coverage, quality and quantity were used for inputs into the estimation and for evaluation of the results
    corecore