Search
Results
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Measurement of the Lambda(b) cross section and the anti-Lambda(b) to Lambda(b) ratio with Lambda(b) to J/Psi Lambda decays in pp collisions at sqrt(s) = 7 TeV
(2012)Physics Letters BThe Λ b differential production cross section and the cross section ratio σ(Λ-b)/σ(Λb) are measured as functions of transverse momentum pTΛb and rapidity |y Λb| in pp collisions at s=7 TeV using data collected by the CMS experiment at the LHC. The measurements are based on Λ b decays reconstructed in the exclusive final state J/ψΛ, with the subsequent decays J/ψ→μ +μ - and Λ→pπ, using a data sample corresponding to an integrated luminosity ...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 -
Search for stopped long-lived particles produced in pp collisions at √s=7TeV
(2012)Journal of High Energy PhysicsA search has been performed for long-lived particles that have stopped in the CMS detector, during 7 TeV proton-proton operations of the CERN LHC. The existence of such particles could be inferred from observation of their decays when there were no proton-proton collisions in the CMS detector, namely during gaps between LHC beam crossings. Using a data set in which CMS recorded an integrated luminosity of 4.0 fb−1, and a search interval ...Journal Article -
Measurement of the underlying event activity in pp collisions at √s=0.9 and 7 TeV with the novel jet-area/median approach
(2012)Journal of High Energy PhysicsThe first measurement of the charged component of the underlying event using the novel “jet-area/median” approach is presented for proton-proton collisions at centre-of-mass energies of 0.9 and 7 TeV. The data were recorded in 2010 with the CMS experiment at the LHC. A new observable, sensitive to soft particle production, is introduced and investigated inclusively and as a function of the event scale defined by the transverse momentum ...Journal Article -
Search for leptonic decays of W′ bosons in pp collisions at sqrt(s)=7 TeV
(2012)Journal of High Energy PhysicsA search for a new heavy gauge boson W′ decaying to an electron or muon, plus a low mass neutrino, is presented. This study uses data corresponding to an integrated luminosity of 5.0 fb−1, collected using the CMS detector in pp collisions at a centre-of-mass energy of 7 TeV at the LHC. Events containing a single electron or muon and missing transverse momentum are analyzed. No significant excess of events above the standard model expectation ...Journal Article -
Search for new physics in events with same-sign dileptons and b-tagged jets in pp collisions at sqrt(s) = 7 TeV
(2012)Journal of High Energy PhysicsA search for new physics is performed using isolated same-sign dileptons with at least two b-quark jets in the final state. Results are based on a 4.98 fb−1 sample of proton-proton collisions at a centre-of-mass energy of 7 TeV collected by the CMS detector. No excess above the standard model background is observed. Upper limits at 95% confidence level are set on the number of events from non-standard-model sources. These limits are used ...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 -
Search for heavy long-lived charged particles in pp collisions at sqrt(s)=7 TeV
(2012)Physics Letters BThe result of a search for heavy long-lived charged particles produced in pp collisions at √s=7 TeV at the LHC is described. The data sample has been collected using the CMS detector and corresponds to an integrated luminosity of 5.0 fb-1. The inner tracking detectors are used to define a sample of events containing tracks with high momentum and high ionization energy loss. A second sample of events, which have high-momentum tracks ...Journal Article -
Search for a light charged Higgs boson in top quark decays in pp collisions at √s=7TeV
(2012)Journal of High Energy PhysicsResults are presented on a search for a light charged Higgs boson that can be produced in the decay of the top quark t → H+b and which, in turn, decays into τ +ν τ . The analysed data correspond to an integrated luminosity of about 2 fb−1 recorded in protonproton collisions at s√=7TeV by the CMS experiment at the LHC. The search is sensitive to the decays of the top quark pairs tt¯ → H± W ∓ bb¯¯¯ and tt¯ → H±H∓ bb¯¯¯. Various final states ...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