Search
Results
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Study of W boson production in PbPb and pp collisions at √s[NN] = 2.76 TeV
(2012)Physics Letters BA measurement is presented of W-boson production in PbPb collisions carried out at a nucleon-nucleon (NN) centre-of-mass energy root S-NN of 2.76 TeV at the LHC using the CMS detector. In data corresponding to an integrated luminosity of 7.3 mu b(-1), the number of W -> mu v(mu) decays is extracted in the region of muon pseudorapidity vertical bar eta mu vertical bar < 2.1 and transverse momentum p(T)(mu) > 25 GeV/c. Yields of muons found ...Journal Article -
Inclusive and differential measurements of the ttˉ charge asymmetry in proton–proton collisions at 7 TeV
(2012)Physics Letters BThe tt- charge asymmetry is measured in events containing a charged lepton (electron or muon) and at least four jets, one of which is identified as originating from b-quark hadronization. The analyzed dataset corresponds to an integrated luminosity of 5.0 fb -1 collected with the CMS detector at the LHC. An inclusive and three differential measurements of the tt- charge asymmetry as a function of rapidity, transverse momentum, and invariant ...Journal Article -
Search for high mass resonances decaying into τ-lepton pairs in pp collisions at s√=7 TeV
(2012)Physics Letters BA search for high-mass resonances decaying into τ+ τ- is performed using a data sample of pp collisions at s√=7 TeV. The data were collected with the CMS detector at the LHC and correspond to an integrated luminosity of 4.9 fb−1. The number of observed events is in agreement with the standard model prediction. An upper limit on the product of the resonance cross section and branching fraction into τ-lepton pairs is calculated as a function ...Journal Article -
Measurement of the top-quark mass in tt events with dilepton final states in pp collisions at s√ =7 TeV
(2012)The European Physical Journal CThe top-quark mass is measured in proton-proton collisions at s√=7 TeV using a data sample corresponding to an integrated luminosity of 5.0 fb−1 collected by the CMS experiment at the LHC. The measurement is performed in the dilepton decay channel tt¯→(ℓ+νℓb)(ℓ−ν¯¯¯ℓb¯¯¯), where ℓ=e,μ. Candidate top-quark decays are selected by requiring two leptons, at least two jets, and imbalance in transverse momentum. The mass is reconstructed with ...Journal Article -
Observation of a new boson at a mass of 125 GeV with the CMS experiment at the LHC
(2012)Physics Letters BResults are presented from searches for the standard model Higgs boson in proton–proton collisions at √s = 7 and 8 TeV in the Compact Muon Solenoid experiment at the LHC, using data samples corresponding to integrated luminosities of up to 5.1 fb−1 at 7 TeV and 5.3 fb−1 at 8 TeV. The search is performed in five decay modes: γγ, ZZ, W+W−, τ+τ−, and bb. An excess of events is observed above the expected background, with a local significance ...Journal Article -
Observation of a new Xi(b) baryon
(2012)Physical Review LettersThe observation of a new b baryon via its strong decay into Ξ−bπ+ (plus charge conjugates) is reported. The measurement uses a data sample of pp collisions at √s=7 TeV collected by the CMS experiment at the LHC, corresponding to an integrated luminosity of 5.3 fb−1. The known Ξ−b baryon is reconstructed via the decay chain Ξ−b→J/ψΞ−→μ+μ−Λ0π−, with Λ0→pπ−. A peak is observed in the distribution of the difference between the mass of the ...Journal Article -
Search for narrow resonances in dilepton mass spectra in pp collisions at sqrt(s) = 7 TeV
(2012)Physics Letters BA search for narrow, high-mass resonances decaying to electron or muon pairs has been performed using pp collision data collected at √s = 7TeV by the CMS experiment in 2011. The data sample corresponds to an integrated luminosity of approximately 5 fb−1. The event yields observed in the signal regions are consistent with predictions of the standard model backgrounds, and upper limits on the cross section times branching fraction for a ...Journal Article -
A search for a doubly-charged Higgs boson in pp collisions at √s=7 TeV
(2012)The European Physical Journal CA search for a doubly-charged Higgs boson in pp collisions at s√=7 TeV is presented. The data correspond to an integrated luminosity of 4.9 fb−1, collected by the CMS experiment at the LHC. The search is performed using events with three or more isolated charged leptons of any flavor, giving sensitivity to the decays of pair-produced triplet components Φ ++ Φ −−, and Φ ++ Φ − from associated production. No excess is observed compared to ...Journal Article -
Measurement of the relative prompt production rate of χ c2 and χ c1 in pp collisions at √s=7 TeV
(2012)The European Physical Journal CA measurement is presented of the relative prompt production rate of χ c2 and χ c1 with 4.6 fb−1 of data collected by the CMS experiment at the LHC in pp collisions at s√=7 TeV. The two states are measured via their radiative decays χ c→J/ψ+γ, with the photon converting into an e+e− pair for J/ψ rapidity |y(J/ψ)|<1.0 and photon transverse momentum p T(γ)>0.5 GeV/c. The measurement is given for six intervals of p T(J/ψ) between 7 and 25 ...Journal Article -
Combined search for the quarks of a sequential fourth generation
(2012)Physical Review DResults are presented from a search for a fourth generation of quarks produced singly or in pairs in a data set corresponding to an integrated luminosity of 5 fb−1 recorded by the CMS experiment at the LHC in 2011. A novel strategy has been developed for a combined search for quarks of the up and down type in decay channels with at least one isolated muon or electron. Limits on the mass of the fourth-generation quarks and the relevant ...Journal Article