63 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

    Measurement of the Z boson differential cross section in transverse momentum and rapidity in proton-proton collisions at 8 TeV

    Get PDF
    We present a measurement of the Z boson differential cross section in rapidity and transverse momentum using a data sample of pp collision events at a centre-of-mass energy s=8 TeV, corresponding to an integrated luminosity of 19.7 fb-1. The Z boson is identified via its decay to a pair of muons. The measurement provides a precision test of quantum chromodynamics over a large region of phase space. In addition, due to the small experimental uncertainties in the measurement the data has the potential to constrain the gluon parton distribution function in the kinematic regime important for Higgs boson production via gluon fusion. The results agree with the next-to-next-to-leading-order predictions computed with the fewz program. The results are also compared to the commonly used leading-order MadGraph and next-to-leading-order powheg generators. © 2015 CERN for the benefit of the CMS Collaboration

    Identification techniques for highly boosted W bosons that decay into hadrons

    Get PDF

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

    Get PDF

    Search for pair production of third-generation scalar leptoquarks and top squarks in proton–proton collisions at

    Get PDF

    Search for new phenomena in monophoton final states in proton-proton collisions at root s=8 TeV

    Get PDF
    Peer reviewe

    Measurement of the inclusive 3-jet production differential cross section in proton-proton collisions at 7 TeV and determination of the strong coupling constant in the TeV range

    Get PDF
    This paper presents a measurement of the inclusive 3-jet production differential cross section at a proton–proton centre-of-mass energy of 7 TeV using data corresponding to an integrated luminosity of 5 fb-1 collected with the CMS detector. The analysis is based on the three jets with the highest transverse momenta. The cross section is measured as a function of the invariant mass of the three jets in a range of 445–3270 GeV and in two bins of the maximum rapidity of the jets up to a value of 2. A comparison between the measurement and the prediction from perturbative QCD at next-to-leading order is performed. Within uncertainties, data and theory are in agreement. The sensitivity of the observable to the strong coupling constant αS is studied. A fit to all data points with 3-jet masses larger than 664 GeV gives a value of the strong coupling constant of αS(MZ)=0.1171±0.0013(exp)-0.0047+0.0073(theo)

    Constraints on the Higgs boson width from off-shell production and decay to Z-boson pairs

    Get PDF
    Constraints are presented on the total width of the recently discovered Higgs boson, &#915;H , using its relative on-shell and off-shell production and decay rates to a pair of Z bosons, where one Z boson decays to an electron or muon pair, and the other to an electron, muon, or neutrino pair. The analysis is based on the data collected by the CMS experiment at the LHC in 2011 and 2012, corresponding to integrated luminosities of 5.1 fb&#8722;1 at a center-of-mass energy s=7 TeV and 19.7 fb&#8722;1 at s=8 TeV . A simultaneous maximum likelihood fit to the measured kinematic distributions near the resonance peak and above the Z-boson pair production threshold leads to an upper limit on the Higgs boson width of &#915;H<22 MeV at a 95% confidence level, which is 5.4 times the expected value in the standard model at the measured mass of mH=125.6 GeV

    Search for new phenomena in monophoton final states in proton-proton collisions at √s=TeV

    Get PDF
    Results are presented from a search for new physics in final states containing a photon and missing transverse momentum. The data correspond to an integrated luminosity of 19.6 fb−1 collected in proton–proton collisions at s=8 TeV with the CMS experiment at the LHC. No deviation from the standard model predictions is observed for these final states. New, improved limits are set on dark matter production and on parameters of models with large extra dimensions. In particular, the first limits from the LHC on branon production are found and significantly extend previous limits from LEP and the Tevatron. An upper limit of 14.0 fb on the cross section is set at the 95% confidence level for events with a monophoton final state with photon transverse momentum greater than 145 GeV and missing transverse momentum greater than 140 GeV
    corecore