Search
Results
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Measurement of prompt J/ψ pair production in pp collisions at √s = 7 Tev
(2014)Journal of High Energy PhysicsProduction of prompt J/ψ meson pairs in proton-proton collisions at s√ = 7 TeV is measured with the CMS experiment at the LHC in a data sample corresponding to an integrated luminosity of about 4.7 fb−1. The two J/ψ mesons are fully reconstructed via their decays into μ + μ − pairs. This observation provides for the first time access to the high-transverse-momentum region of J/ψ pair production where model predictions are not yet established. ...Journal Article -
Measurement of top quark-antiquark pair production in association with a W or Z boson in pp collisions at √s=8 TeV
(2014)The European Physical Journal CA measurement of the cross section for the production of top quark–antiquark pairs (tt¯) in association with a vector boson V (W or Z) in proton-proton collisions at s√=8 TeV is presented. The results are based on a dataset corresponding to an integrated luminosity of 19.5 fb−1 recorded with the CMS detector at the LHC. The measurement is performed in three leptonic (e and μ) channels: a same-sign dilepton analysis targeting tt¯W events, ...Journal Article -
Evidence of b -Jet Quenching in PbPb Collisions at √sNN =2.76 TeV
(2014)Physical Review LettersThe production of jets associated to bottom quarks is measured for the first time in PbPb collisions at a center-of-mass energy of 2.76 TeV per nucleon pair. Jet spectra are reported in the transverse momentum (pT) range of 80-250GeV/c, and within pseudorapidity |η|<2. The nuclear modification factor (RAA) calculated from these spectra shows a strong suppression in the b-jet yield in PbPb collisions relative to the yield observed in pp ...Journal Article -
Searches for electroweak production of charginos, neutralinos, and sleptons decaying to leptons and W, Z, and Higgs bosons in pp collisions at 8 TeV
(2014)The European Physical Journal CSearches for the direct electroweak production of supersymmetric charginos, neutralinos, and sleptons in a variety of signatures with leptons and W, Z, and Higgs bosons are presented. Results are based on a sample of proton-proton collision data collected at center-of-mass energy s√=8TeV with the CMS detector in 2012, corresponding to an integrated luminosity of 19.5 fb-1. The observed event rates are in agreement with expectations from ...Journal Article -
Search for the associated production of the Higgs boson with a top-quark pair
(2014)Journal of High Energy PhysicsA search for the standard model Higgs boson produced in association with a top-quark pair (tt¯H) is presented, using data samples corresponding to integrated luminosities of up to 5.1 fb−1 and 19.7 fb−1 collected in pp collisions at center-of-mass energies of 7 TeV and 8 TeV respectively. The search is based on the following signatures of the Higgs boson decay: H → hadrons, H → photons, and H → leptons. The results are characterized by ...Journal Article -
Search for massive resonances decaying into pairs of boosted bosons in semi-leptonic final states at √s = 8 TeV
(2014)Journal of High Energy PhysicsA search for new resonances decaying to WW, ZZ, or WZ is presented. Final states are considered in which one of the vector bosons decays leptonically and the other hadronically. Results are based on data corresponding to an integrated luminosity of 19.7 fb−1 recorded in proton-proton collisions at s√ = 8 TeV with the CMS detector at the CERN LHC. Techniques aiming at identifying jet substructures are used to analyze signal events in which ...Journal Article -
Search for WWγ and WZγ production and constraints on anomalous quartic gauge couplings in pp collisions at √s=8 TeV
(2014)Physical Review DA search for WVγ triple vector boson production is presented based on events containing a W boson decaying to a muon or an electron and a neutrino, a second V (W or Z) boson, and a photon. The data correspond to an integrated luminosity of 19.3 fb−1 collected in 2012 with the CMS detector at the LHC in pp collisions at √s=8 TeV. An upper limit of 311 fb on the cross section for the WVγ production process is obtained at 95% confidence ...Journal Article -
Measurement of jet fragmentation in PbPb and pp collisions at √sNN = 2.76 TeV
(2014)Physical Review CThe jet fragmentation function of inclusive jets with transverse momentum pT above 100GeV/c in PbPb collisions has been measured using reconstructed charged particles with pT above 1GeV/c in a cone of radius 0.3 around the jet axis. A data sample of PbPb collisions collected in 2011 at a nucleon-nucleon center-of-mass energy of √sNN=2.76TeV corresponding to an integrated luminosity of 150μb−1 is used. The results for PbPb collisions as a ...Journal Article -
Measurement of the muon charge asymmetry in inclusive pp→W+X production at √s = 7 Tev and an improved determination of light parton distribution functions
(2014)Physical Review DMeasurements of the muon charge asymmetry in inclusive pp→W+X production at √s=7 TeV are presented. The data sample corresponds to an integrated luminosity of 4.7 fb−1 recorded with the CMS detector at the LHC. With a sample of more than 20 million W→μν events, the statistical precision is greatly improved in comparison to previous measurements. These new results provide additional constraints on the parton distribution functions of the ...Journal Article -
Measurement of jet multiplicity distributions in tt production in pp collisions at √s = 7TeV
(2014)The European Physical Journal CThe normalised differential top quark-antiquark production cross section is measured as a function of the jet multiplicity in proton-proton collisions at a centre-of-mass energy of 7TeV at the LHC with the CMS detector. The measurement is performed in both the dilepton and lepton+jets decay channels using data corresponding to an integrated luminosity of 5.0fb−1. Using a procedure to associate jets to decay products of the top quarks, the ...Journal Article