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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 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 -
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 Dark Matter and Large Extra Dimensions in pp Collisions Yielding a Photon and Missing Transverse Energy
(2012)Physical Review LettersResults are presented from a search for new physics in the final state containing a photon (γ) and missing transverse energy (E̸T). The data correspond to an integrated luminosity of 5.0 fb−1 collected in pp collisions at √s=7 TeV by the CMS experiment. The observed event yield agrees with standard-model expectations for the γ+E̸T events. Using models for the production of dark-matter particles (χ), we set 90% confidence level (C.L.) ...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 -
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 -
Inclusive search for squarks and gluinos in pp collisions at √s=7 TeV
(2012)Physical Review DA search is performed for heavy particle pairs produced in √s=7 TeV proton-proton collisions with 35 pb−1 of data collected by the CMS experiment at the LHC. The search is sensitive to squarks and gluinos of generic supersymmetry models, provided they are kinematically accessible, with minimal assumptions on properties of the lightest superpartner particle. The kinematic consistency of the selected events is tested against the hypothesis ...Journal Article -
Performance of CMS muon reconstruction in pp collision events at √s = 7 TeV
(2012)Journal of InstrumentationThe performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 pb−1 of data collected in pp collisions at √s = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV/c is above 95% over ...Journal Article