Suche
Ergebnisse
-
Measurement of the underlying event in the Drell–Yan process in proton–proton collisions at √s = 7 TeV
(2012)The European Physical Journal CA measurement of the underlying event (UE) activity in proton–proton collisions at a center-of-mass energy of 7 TeV is performed using Drell–Yan events in a data sample corresponding to an integrated luminosity of 2.2 fb−1, collected by the CMS experiment at the LHC. The activity measured in the muonic final state (qq¯¯¯→μ+μ−) is corrected to the particle level and compared with the predictions of various Monte Carlo generators and ...Journal Article -
Measurement of isolated photon production in pp and PbPb collisions at root s(NN)=2.76 TeV
(2012)Physics Letters BIsolated photon production is measured in proton-proton and lead-lead collisions at nucleon-nucleon centre-of-mass energies of 2.76 TeV in the pseudorapidity range |η|<1.44 and transverse energies E T between 20 and 80 GeV with the CMS detector at the LHC. The measured E T spectra are found to be in good agreement with next-to-leading-order perturbative QCD predictions. The ratio of PbPb to pp isolated photon E T-differential yields, ...Journal Article -
Study of high-pT charged particle suppression in PbPb compared to pp collisions at √sNN=2.76 TeV
(2012)The European Physical Journal CThe transverse momentum spectra of charged particles have been measured in pp and PbPb collisions at sNN−−−−√=2.76 TeV by the CMS experiment at the LHC. In the transverse momentum range p T=5–10 GeV/c, the charged particle yield in the most central PbPb collisions is suppressed by up to a factor of 7 compared to the pp yield scaled by the number of incoherent nucleon–nucleon collisions. At higher p T, this suppression is significantly ...Journal Article -
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 neutral Higgs bosons decaying to tau pairs in pp collisions at sqrt(s)=7 TeV
(2012)Physics Letters BA search for neutral Higgs bosons decaying to tau pairs at a center-of-mass energy of 7 TeV is performed using a dataset corresponding to an integrated luminosity of 4.6 fb−1 recorded by the CMS experiment at the LHC. The search is sensitive to both the standard model Higgs boson and to the neutral Higgs bosons predicted by the minimal supersymmetric extension of the standard model (MSSM). No excess of events is observed in the tau-pair ...Journal Article -
Search for physics beyond the standard model in events with a Z boson, jets, and missing transverse energy in pp collisions at √s = 7 TeV
(2012)Physics Letters BA search is presented for physics beyond the standard model (BSM) in events with a Z boson, jets, and missing transverse energy (ETmiss). This signature is motivated by BSM physics scenarios, including supersymmetry. The study is performed using a sample of proton-proton collision data collected at √s=7 TeV with the CMS experiment at the LHC, corresponding to an integrated luminosity of 4.98 fb -1. The contributions from the dominant ...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 -
Measurement of the charge asymmetry in top-quark pair production in proton-proton collisions at root s=7 TeV
(2012)Physics Letters BThe difference in angular distributions between top quarks and antiquarks, commonly referred to as the charge asymmetry, is measured in pp collisions at the LHC with the CMS experiment. The data sample corresponds to an integrated luminosity of 1.09fb -1 at a centre-of-mass energy of 7 TeV. Top-quark pairs are selected in the final state with an electron or muon and four or more jets. At least one jet is identified as originating from ...Journal Article -
Combined results of searches for the standard model Higgs boson in pp collisions at root s=7 TeV
(2012)Physics Letters BCombined results are reported from searches for the standard model Higgs boson in proton-proton collisions at s=7 TeV in five Higgs boson decay modes: γγ, bb, ττ, WW, and ZZ. The explored Higgs boson mass range is 110-600 GeV. The analysed data correspond to an integrated luminosity of 4.6-4.8 fb -1. The expected excluded mass range in the absence of the standard model Higgs boson is 118-543 GeV at 95% CL. The observed results exclude the ...Journal Article -
Search for New Physics with Same-Sign Isolated Dilepton Events with Jets and Missing Transverse Energy
(2012)Physical ReviewA search for new physics is performed in events with two same-sign isolated leptons, hadronic jets, and missing transverse energy in the final state. The analysis is based on a data sample corresponding to an integrated luminosity of 4.98 fb−1 produced in pp collisions at a center-of-mass energy of 7 TeV collected by the CMS experiment at the LHC. This constitutes a factor of 140 increase in integrated luminosity over previously published ...Journal Article