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 -
Jet momentum dependence of jet quenching in PbPb collisions at root s(NN)=2.76 TeV
(2012)Physics Letters BDijet production in PbPb collisions at a nucleon–nucleon center-of-mass energy of 2.76 TeV is studied with the CMS detector at the LHC. A data sample corresponding to an integrated luminosity of 150 μb−1 is analyzed. Jets are reconstructed using combined information from tracking and calorimetry, using the anti-kT algorithm with R = 0.3. The dijet momentum balance and angular correlations are studied as a function of collision centrality ...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 -
Search for the standard model Higgs boson decaying to bottom quarks in pp collisions at sqrt(s)=7 TeV
(2012)Physics Letters BA search for the standard model Higgs boson (H) decaying to (b) over barb when produced in association with weak vector bosons (V) is reported for the following modes: W(mu nu)H, W(e nu)H, Z(mu mu)H, Z(ee)H and Z(nu nu)H. The search is performed in a data sample corresponding to an integrated luminosity of 4.7 fb(-1), recorded by the CMS detector in proton-proton collisions at the LHC with a center-of-mass energy of 7 TeV. No significant ...Journal Article -
Search for the standard model Higgs boson decaying into two photons in pp collisions at √s=7 TeV
(2012)Physics Letters BA search for a Higgs boson decaying into two photons is described. The analysis is performed using a dataset recorded by the CMS experiment at the LHC from pp collisions at a center-of-mass energy of 7 TeV, which corresponds to an integrated luminosity of 4.8 fb−1. Limits are set on the cross section of the standard model Higgs boson decaying to two photons. The expected exclusion limit at 95% confidence level is between 1.4 and 2.4 times ...Journal Article -
Azimuthal Anisotropy of Charged Particles at High Transverse Momenta in Pb-Pb Collisions at √sNN=2.76 TeV
(2012)Physical Review LettersThe azimuthal anisotropy of charged particles in Pb-Pb collisions at √sNN=2.76 TeV is measured with the CMS detector at the LHC over an extended transverse momentum (pT) range up to approximately 60 GeV/c. The data cover both the low-pT region associated with hydrodynamic flow phenomena and the high-pT region where the anisotropies may reflect the path-length dependence of parton energy loss in the created medium. The anisotropy parameter ...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