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Measurement of the Electron Charge Asymmetry in Inclusive W Production in pp Collisions at √s=7 TeV
(2012)Physical Review LettersA measurement of the electron charge asymmetry in inclusive pp→W+X→eν+X production at √s=7 TeV is presented based on data recorded by the CMS detector at the LHC and corresponding to an integrated luminosity of 840 pb−1. The electron charge asymmetry reflects the unequal production of W+ and W− bosons in pp collisions. The electron charge asymmetry is measured in bins of the absolute value of electron pseudorapidity in the range of ...Journal Article -
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 -
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 -
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