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Search for Z′ resonances decaying to t¯t in dilepton+jets final states in pp collisions at √s=7 TeV
(2013)Physical Review DA search for resonances decaying to top quark-antiquark pairs is performed using a dilepton+jets data sample recorded by the CMS experiment at the LHC in pp collisions at √s=7 TeV corresponding to an integrated luminosity of 5.0 fb−1. No significant deviations from the standard model background are observed. Upper limits are presented for the production cross section times branching fraction of top quark-antiquark resonances for masses ...Journal Article -
Search for supersymmetry in events with opposite-sign dileptons and missing transverse energy using an artificial neural network
(2013)Physical Review DJournal Article -
Measurement of associated production of vector bosons and top quark-antiquark pairs in pp collisions at √s=7 TeV
(2013)Physical Review LettersThe first measurement of vector-boson production associated with a top quark-antiquark pair in proton-proton collisions at √s=7 TeV is presented. The results are based on a data set corresponding to an integrated luminosity of 5.0 fb−1, recorded by the CMS detector at the LHC in 2011. The measurement is performed in two independent channels through a trilepton analysis of t¯tZ events and a same-sign dilepton analysis of t¯tV (V=W or Z) ...Journal Article -
Study of the Mass and Spin-Parity of the Higgs Boson Candidate via Its Decays to Z Boson Pairs
(2013)Physical Review LettersA study is presented of the mass and spin-parity of the new boson recently observed at the LHC at a mass near 125 GeV. An integrated luminosity of 17.3 fb−1, collected by the CMS experiment in proton-proton collisions at center-of-mass energies of 7 and 8 TeV, is used. The measured mass in the ZZ channel, where both Z bosons decay to e or μ pairs, is 126.2±0.6(stat)±0.2(syst) GeV. The angular distributions of the lepton pairs in this ...Journal Article -
Measurement of the Υ(1S), Υ(2S), and Υ(3S) Polarizations in pp Collisions at √s=7 TeV
(2013)Physical Review LettersThe polarizations of the Υ(1S), Υ(2S), and Υ(3S) mesons are measured in proton-proton collisions at √s=7 TeV, using a data sample of Υ(nS)→μ+μ− decays collected by the CMS experiment, corresponding to an integrated luminosity of 4.9 fb−1. The dimuon decay angular distributions are analyzed in three different polarization frames. The polarization parameters λϑ, λφ, and λϑφ, as well as the frame-invariant quantity ˜λ, are presented as a ...Journal Article -
Search for supersymmetry in events with photons and low missing transverse energy in pp collisions at root s=7 TeV
(2013)Physics Letters BMany models of new physics, including versions of supersymmetry (SUSY), predict production of events with low missing transverse energy, electroweak gauge bosons, and many energetic final-state particles. The stealth SUSY model yields this signature while conserving R-parity by means of a new hidden sector in which SUSY is approximately conserved. The results of a general search for new physics, with no requirement on missing transverse ...Journal Article -
Search for Pair Production of Third-Generation Leptoquarks and Top Squarks in pp Collisions at √s=7 TeV
(2013)Physical Review LettersResults are presented from a search for the pair production of third-generation scalar and vector leptoquarks, as well as for top squarks in R-parity-violating supersymmetric models. In either scenario, the new, heavy particle decays into a τ lepton and a b quark. The search is based on a data sample of pp collisions at √s=7 TeV, which is collected by the CMS detector at the LHC and corresponds to an integrated luminosity of 4.8 fb−1. ...Journal Article -
Evidence for associated production of a single top quark and W boson in pp collisions at √s=7 TeV
(2013)Physical Review LettersEvidence is presented for the associated production of a single top quark and W boson in pp collisions at √s=7 TeV with the CMS experiment at the LHC. The analyzed data correspond to an integrated luminosity of 4.9 fb−1. The measurement is performed using events with two leptons and a jet originated from a b quark. A multivariate analysis based on kinematic properties is utilized to separate the t¯t background from the signal. The ...Journal Article -
Search for a narrow, spin-2 resonance decaying to a pair of Z bosons in the qq¯ℓ+ℓ− final state
(2013)Physics Letters BResults are presented from a search for a narrow, spin-2 resonance decaying into a pair of Z bosons, with one Z-boson decaying into leptons (e+e− or μ+μ−) and the other into jets. An example of such a resonance is the Kaluza–Klein graviton, GKK, predicted in Randall–Sundrum models. The analysis is based on a 4.9 fb−1 sample of proton–proton collisions at a center-of-mass energy of 7 TeV, collected with the CMS detector at the LHC. Kinematic ...Journal Article -
Measurement of the azimuthal anisotropy of neutral pions in PbPb collisions at √sNN=2.76 TeV
(2013)Physical Review LettersFirst measurements of the azimuthal anisotropy of neutral pions produced in Pb-Pb collisions at a center-of-mass energy of √sNN=2.76 TeV are presented. The amplitudes of the second Fourier component (v2) of the π0 azimuthal distributions are extracted using an event-plane technique. The values of v2 are studied as a function of the neutral pion transverse momentum (pT) for different classes of collision centrality in the kinematic range ...Journal Article