Suche
Ergebnisse
-
Observation of a peaking structure in the J/ψφ mass spectrum from B±→J/ψφK± decays
(2014)Physics Letters BA peaking structure in the J/ψφ mass spectrum near threshold is observed in B ±→J/ψφK± decays, produced in pp collisions at √s=7 TeV collected with the CMS detector at the LHC. The data sample, selected on the basis of the dimuon decay mode of the J/ψ, corresponds to an integrated luminosity of 5.2 fb-1. Fitting the structure to an S-wave relativistic Breit-Wigner lineshape above a three-body phase-space nonresonant component gives a ...Journal Article -
Measurement of the top-quark mass in all-jets tt events in pp collisions at √s = 7 TeV
(2014)The European Physical Journal CThe 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√=7 TeV in 2011 and corresponds to an integrated luminosity of 3.54 fb−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.) ...Journal Article -
Probing color coherence effects in pp collisions at √s = 7 TeV
(2014)The European Physical Journal CA study of color coherence effects in pp collisions at a center-of-mass energy of 7TeV is presented. The data used in the analysis were collected in 2010 with the CMS detector at the LHC and correspond to an integrated luminosity of 36 pb−1. Events are selected that contain at least three jets and where the two jets with the largest transverse momentum exhibit a back-to-back topology. The measured angular correlation between the second- ...Journal Article -
Study of the production of charged pions, kaons, and protons in pPb collisions at √sNN = 5.02 TeV
(2014)The European Physical Journal CSpectra of identified charged hadrons are measured in pPb collisions with the CMS detector at the LHC at sNN−−−−√=5.02TeV. Charged pions, kaons, and protons in the transverse-momentum range pT≈0.1–1.7GeV/c and laboratory rapidity |y|<1 are identified via their energy loss in the silicon tracker. The average pT increases with particle mass and the charged multiplicity of the event. The increase of the average pT with charged multiplicity ...Journal Article -
Determination of the top-quark pole mass and strong coupling constant from the tt¯ production cross section in pp collisions at √s = 7 TeV
(2014)Physics Letters BThe inclusive cross section for top-quark pair production measured by the CMS experiment in proton–proton collisions at a center-of-mass energy of 7 TeV is compared to the QCD prediction at next-to-next-to-leading order with various parton distribution functions to determine the top-quark pole mass, mt pole, or the strong coupling constant, αS. With the parton distribution function set NNPDF2.3, a pole mass of 176.7−3.4 +3.8 GeV is obtained ...Journal Article -
Modification of jet shapes in PbPb collisions at sNN=2.76TeV
(2014)Physics Letters BThe first measurement of jet shapes, defined as the fractional transverse momentum radial distribution, for inclusive jets produced in heavy-ion collisions is presented. Data samples of PbPb and pp collisions, corresponding to integrated luminosities of 150 mu b(-1) and 5.3 pb(-1) respectively, were collected at a nucleon-nucleon centre-of-mass energy of root s(NN) = 2.76 TeV with the CMS detector at the LHC. The jets are reconstructed ...Journal Article -
Search for baryon number violation in top-quark decays
(2014)Physics Letters BA search for baryon number violation (BNV) in top-quark decays is performed using pp collisions produced by the LHC at s=8 TeV. The top-quark decay considered in this search results in one light lepton (muon or electron), two jets, but no neutrino in the final state. Data used for the analysis were collected by the CMS detector and correspond to an integrated luminosity of 19.5 fb-1. The event selection is optimized for top quarks produced ...Journal Article -
Measurement of Inclusive W and Z Boson Production Cross Sections in pp Collisions at √s =8 Te V
(2014)Physical Review LettersA measurement of total and fiducial inclusive W and Z boson production cross sections in pp collisions at √s=8 TeV is presented. Electron and muon final states are analyzed in a data sample collected with the CMS detector corresponding to an integrated luminosity of 18.2±0.5 pb−1. The measured total inclusive cross sections times branching fractions are σ(pp→WX)×B(W→ℓν)=12.21±0.03(stat)±0.24(syst)±0.32(lum) nb and σ(pp→ZX)×B(Z→ℓ+ℓ−)= ...Journal Article -
Measurement of the production cross sections for a Z boson and one or more b jets in pp collisions at sqrt(s) = 7 TeV
(2014)Journal of High Energy PhysicsThe production of a Z boson, decaying into two leptons and produced in association with one or more b jets, is studied using proton-proton collisions delivered by the LHC at a centre-of-mass energy of 7 TeV. The data were recorded in 2011 with the CMS detector and correspond to an integrated luminosity of 5 fb−1. The Z(ℓℓ) + b-jets cross sections (where ℓℓ = μμ or ee) are measured separately for a Z boson produced with exactly one b jet ...Journal Article -
Measurement of the Wγ and Zγ inclusive cross sections in pp collisions at √s=7 TeV and limits on anomalous triple gauge boson couplings
(2014)Physical Review DMeasurements of Wγ and Zγ production in proton-proton collisions at √s=7 TeV are used to extract limits on anomalous triple gauge couplings. The results are based on data recorded by the CMS experiment at the LHC that correspond to an integrated luminosity of 5.0 fb−1. The cross sections are measured for photon transverse momenta pγT>15 GeV, and for separations between photons and final-state charged leptons in the pseudorapidity-azimuthal ...Journal Article