Search
Results
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Measurement of the jet mass in highly boosted tt¯ events from pp collisions at √s=8 TeV
(2017)The European Physical Journal CThe first measurement of the jet mass mjet of top quark jets produced in tt¯ events from pp collisions at s√=8TeV is reported for the jet with the largest transverse momentum pT in highly boosted hadronic top quark decays. The data sample, collected with the CMS detector, corresponds to an integrated luminosity of 19.7fb−1. The measurement is performed in the lepton+jets channel in which the products of the semileptonic decay t→bW with ...Journal Article -
Multiplicity and rapidity dependence of strange hadron production in pp, pPb, and PbPb collisions at the LHC
(2017)Physics Letters BMeasurements of strange hadron (KS 0, Λ+Λ‾, and Ξ−+Ξ‾+) transverse momentum spectra in pp, pPb, and PbPb collisions are presented over a wide range of rapidity and event charged-particle multiplicity. The data were collected with the CMS detector at the CERN LHC in pp collisions at s=7TeV, pPb collisions at sNN=5.02TeV, and PbPb collisions at sNN=2.76TeV. The average transverse kinetic energy is found to increase with multiplicity, at a ...Journal Article -
Measurement of the mass difference between top quark and antiquark in pp collisions at √s = 8 TeV
(2017)Physics Letter BThe invariance of the standard model (SM) under the CPT transformation predicts equality of particle and antiparticle masses. This prediction is tested by measuring the mass difference between the top quark and antiquark (Δmt=mt−mt) that are produced in pp collisions at a center-of-mass energy of 8TeV, using events with a muon or an electron and at least four jets in the final state. The analysis is based on data corresponding to an ...Journal Article -
Measurement of the production cross section of the W boson in association with two b jets in pp collisions at √s = 8 TeV
(2017)The European Physical Journal CThe production cross section of a W boson in association with two b jets is measured using a sample of proton–proton collisions at √s=8TeV collected by the CMS experiment at the CERN LHC. The data sample corresponds to an integrated luminosity of 19.8fb-1. The W bosons are reconstructed via their leptonic decays, W→ℓν, where ℓ=μ or e. The fiducial region studied contains exactly one lepton with transverse momentum pℓT>30GeV and pseudorapidity ...Journal Article -
Search for new phenomena with multiple charged leptons in proton–proton collisions at √s=13TeV
(2017)The European Physical Journal CResults are reported from a search for physics beyond the standard model in final states with at least three charged leptons, in any combination of electrons or muons. The data sample corresponds to an integrated luminosity of 2.3fb−1 of proton–proton collisions at s√=13TeV, recorded by the CMS experiment at the LHC in 2015. Two jets are required in each event, providing good sensitivity to strong production of gluinos and squarks. The ...Journal Article -
Measurements of the tt production cross section in lepton+jets final states in pp collisions at 8 TeV and ratio of 8 to 7 TeV cross sections
(2017)The European Physical Journal CA measurement of the top quark pair production (tt¯) cross section in proton–proton collisions at the centre-of-mass energy of 8TeV is presented using data collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 19.6fb−1. This analysis is performed in the tt¯ decay channels with one isolated, high transverse momentum electron or muon and at least four jets, at least one of which is required to be identified ...Journal Article -
Suppression of ϒ(1S), ϒ(2S), and ϒ(3S) quarkonium states in PbPb collisions at √sNN = 2.76 TeV
(2017)Physics Letters BThe production yields of ϒ(1S), ϒ(2S), and ϒ(3S) quarkonium states are measured through their decays into muon pairs in the CMS detector, in PbPb and pp collisions at the centre-of-mass energy per nucleon pair of 2.76 TeV. The data correspond to integrated luminosities of 166μb−1 and 5.4pb−1 for PbPb and pp collisions, respectively. Differential production cross sections are reported as functions of ϒ rapidity y up to 2.4, and transverse ...Journal Article -
Observation of charge-dependent azimuthal correlations in pPb collisions and its implication for the search for the chiral magnetic effect
(2017)Physical Review LettersCharge-dependent azimuthal particle correlations with respect to the second-order event plane in p−Pb and PbPb collisions at a nucleon-nucleon center-of-mass energy of 5.02 TeV have been studied with the CMS experiment at the LHC. The measurement is performed with a three-particle correlation technique, using two particles with the same or opposite charge within the pseudorapidity range |η|<2.4, and a third particle measured in the hadron ...Journal Article -
Suppression and azimuthal anisotropy of prompt and nonprompt J/ψ production in PbPb collisions at √sNN = 2.76 TeV
(2017)The European Physical Journal CThe nuclear modification factor RAA and the azimuthal anisotropy coefficient v2 of prompt and nonprompt (i.e. those from decays of b hadrons) J/ψ mesons, measured from PbPb and pp collisions at √sNN = 2.76 TeVat the LHC, are reported. The results are presented in several event centrality intervals and several kinematic regions, for transverse momenta pT > 6.5GeV/c and rapidity |y| < 2.4, extending down to pT = 3GeV/c in the 1.6 < |y| < ...Journal Article -
Evidence for collectivity in pp collisions at the LHC
(2017)Physics Letters BMeasurements of two- and multi-particle angular correlations in pp collisions at s=5,7, and 13TeV are presented as a function of charged-particle multiplicity. The data, corresponding to integrated luminosities of 1.0pb−1 (5 TeV), 6.2pb−1 (7 TeV), and 0.7pb−1 (13 TeV), were collected using the CMS detector at the LHC. The second-order (v2) and third-order (v3) azimuthal anisotropy harmonics of unidentified charged particles, as well as ...Journal Article