Search
Results
-
Study of the inclusive production of charged pions, kaons, and protons in pp collisions at √s=0.9, 2.76, and 7 TeV
(2012)The European Physical Journal CSpectra of identified charged hadrons are measured in pp collisions at the LHC for s√=0.9,2.76, and 7 TeV. Charged pions, kaons, and protons in the transverse-momentum range p T≈0.1–1.7 GeV/c and for rapidities |y|<1 are identified via their energy loss in the CMS silicon tracker. The average p T increases rapidly with the mass of the hadron and the event charged-particle multiplicity, independently of the center-of-mass energy. The fully ...Journal Article -
Search for heavy Majorana neutrinos in μ±μ±+jets and e±e±+jets events in pp collisions at √s =7 TeV
(2012)Physics Letters BA search for excited leptons is carried out with the CMS detector at the LHC, using 36 pb-1 of pp collision data recorded at s=7 TeV. The search is performed for associated production of a lepton and an oppositely charged excited lepton pp→ℓℓ*, followed by the decay ℓ*→ℓγ, resulting in the ℓℓγ final state, where ℓ=e,μ. No excess of events above the standard model expectation is observed. Interpreting the findings in the context of ℓ* ...Journal Article -
Search for heavy lepton partners of neutrinos in proton–proton collisions in the context of the type III seesaw mechanism
(2012)Physics Letters BA search is presented in proton-proton collisions at s=7TeV for fermionic triplet states expected in type III seesaw models. The search is performed using final states with three isolated charged leptons and an imbalance in transverse momentum. The data, collected with the CMS detector at the LHC, correspond to an integrated luminosity of 4.9fb -1. No excess of events is observed above the background predicted by the standard model, and ...Journal Article -
Study of the Dijet Mass Spectrum in pp→W+jets Events at √s=7 TeV
(2012)Physical Review LettersWe report an investigation of the invariant mass spectrum of the two jets with highest transverse momentum in pp→W+2-jet and W+3-jet events to look for resonant enhancement. The data sample corresponds to an integrated luminosity of 5.0 fb−1 collected with the CMS detector at √s=7 TeV. We find no evidence for the anomalous structure reported by the CDF Collaboration, and establish an upper limit of 5.0 pb at 95% confidence level on the ...Journal Article -
Observation of Sequential gamma Suppression in PbPb Collisions
(2012)Physical Review LettersThe suppression of the individual Υ(nS) states in PbPb collisions with respect to their yields in pp data has been measured. The PbPb and pp data sets used in the analysis correspond to integrated luminosities of 150 μb−1 and 230 nb−1, respectively, collected in 2011 by the CMS experiment at the LHC, at a center-of-mass energy per nucleon pair of 2.76 TeV. The Υ(nS) yields are measured from the dimuon invariant mass spectra. The suppression ...Journal Article -
Search for three-jet resonances in pp collisions at √s=7 TeV
(2012)Physics Letters BResults are reported from a search for the production of three-jet resonances in pp collisions at a center-of-mass energy √s=7 TeV. The study uses the data sample collected by the CMS experiment at the LHC in 2011, corresponding to an integrated luminosity of 5.0fb-1. Events with high jet multiplicity and a large scalar sum of jet transverse momenta are analyzed for the presence of resonances in the three-jet invariant mass spectrum. No ...Journal Article -
Search for pair produced fourth-generation up-type quarks in pp collisions at √s=7 TeV with a lepton in the final state
(2012)Physics Letters BThe results of a search for the pair production of a fourth-generation up-type quark (t') in proton-proton collisions at √s=7 TeV are presented, using data corresponding to an integrated luminosity of about 5.0 fb -1 collected by the Compact Muon Solenoid experiment at the LHC. The t' quark is assumed to decay exclusively to a W boson and a b quark. Events with a single isolated electron or muon, missing transverse momentum, and at least ...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 -
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