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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 -
Observation of the associated production of a single top quark and a W Boson in pp collisions at √s = 8 TeV
(2014)Physical Review LettersJournal Article -
Alignment of the CMS tracker with LHC and cosmic ray data
(2014)Journal of InstrumentationThe central component of the CMS detector is the largest silicon tracker ever built. The precise alignment of this complex device is a formidable challenge, and only achievable with a significant extension of the technologies routinely used for tracking detectors in the past. This article describes the full-scale alignment procedure as it is used during LHC operations. Among the specific features of the method are the simultaneous ...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 properties of a Higgs boson in the four-lepton final state
(2014)Physical Review DThe properties of a Higgs boson candidate are measured in the H→ZZ→4ℓ decay channel, with ℓ=e, μ, using data from pp collisions corresponding to an integrated luminosity of 5.1 fb−1 at the center-of-mass energy of √s=7 TeV and 19.7 fb−1 at √s=8 TeV, recorded with the CMS detector at the LHC. The new boson is observed as a narrow resonance with a local significance of 6.8 standard deviations, a measured mass of 125.6±0.4(stat)±0.2(syst) GeV, ...Journal Article -
Search for Flavor-Changing Neutral Currents in Top-Quark Decays t→Zq in pp Collisions at √s = 8 TeV
(2014)Physical Review LettersA search for flavor-changing neutral currents in top-quark decays t → Zq is performed in events produced from the decay chain t¯t → Zq + Wb, where both vector bosons decay leptonically, producing a final state with three leptons (electrons or muons). A data set collected with the CMS detector at the LHC is used, corresponding to an integrated luminosity of 19.7 fb−1 of proton-proton collisions at a center-of-mass energy of 8 TeV. No excess ...Journal Article -
Measurement of four-jet production in proton-proton collisions at √s =7TeV
(2014)Physical Review DMeasurements of the differential cross sections for the production of exactly four jets in proton-proton collisions are presented as a function of the transverse momentum pT and pseudorapidity η, together with the correlations in azimuthal angle and the pT balance among the jets. The data sample was collected in 2010 at a center-of-mass energy of 7 TeV with the CMS detector at the LHC, with an integrated luminosity of 36 pb−1. The cross ...Journal Article -
Measurements of t¯t Spin Correlations and Top-Quark Polarization Using Dilepton Final States in pp Collisions at √s=7 TeV
(2014)Physical Review LettersSpin correlations and polarization in the top quark–antiquark system are measured using dilepton final states produced in pp collisions at the LHC at √s=7 TeV. The data correspond to an integrated luminosity of 5.0 fb−1 collected with the CMS detector. The measurements are performed using events with two oppositely charged leptons (electrons or muons), a significant imbalance in transverse momentum, and two or more jets, where at least ...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 higher-order harmonic azimuthal anisotropy in PbPb collisions at √sNN=2.76 TeV
(2014)Physical Review CMeasurements are presented by the CMS Collaboration at the Large Hadron Collider (LHC) of the higher-order harmonic coefficients that describe the azimuthal anisotropy of charged particles emitted in √sNN=2.76 TeV PbPb collisions. Expressed in terms of the Fourier components of the azimuthal distribution, the n=3–6 harmonic coefficients are presented for charged particles as a function of their transverse momentum (0.3<pT<8.0GeV/c), ...Journal Article