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Measurement of the t(t)over-bar production cross section and the top quark mass in the dilepton channel in pp collisions at root s=7 Tev
(2011)Journal of High Energy PhysicsThe tt¯ production cross section and top quark mass are measured in proton-proton collisions at s√=7 TeV in a data sample corresponding to an integrated luminosity of 36 pb−1 collected by the CMS experiment. The measurements are performed in events with two leptons (electrons or muons) in the final state. Results of the cross section measurement in events with and without b-quark identification are obtained and combined. The measured value ...Journal Article -
Search for new physics with jets and missing transverse momentum in pp collisions at s√=7 TeV
(2011)Journal of High Energy PhysicsA search for new physics is presented based on an event signature of at least three jets accompanied by large missing transverse momentum, using a data sample corresponding to an integrated luminosity of 36 pb−1 collected in proton-proton collisions at s√=7 TeV with the CMS detector at the LHC. No excess of events is observed above the expected standard model backgrounds, which are all estimated from the data. Exclusion limits are presented ...Journal Article -
Measurement of energy flow at large pseudorapidities in pp collisions at √s = 0.9 and 7 TeV
(2011)Journal of High Energy Physicshe energy flow, dE/dη, is studied at large pseudorapidities in proton-proton collisions at the LHC, for centre-of-mass energies of 0.9 and 7 TeV. The measurements are made using the CMS detector in the pseudorapidity range 3.15 < |η| < 4.9, for both minimum-bias events and events with at least two high-momentum jets. The data are compared to various pp Monte Carlo event generators whose theoretical models and input parameter values are ...Journal Article -
Long-range and short-range dihadron angular correlations in central PbPb collisions at root s(NN)=2.76 TeV
(2011)Journal of High Energy PhysicsFirst measurements of dihadron correlationsfor charged particles are presented for central PbPb collisions at a nucleon-nucleon center-of-mass energy of 2.76TeV over a broad range in relative pseudorapidity (∆η) and the full range of relative azimuthal angle (∆ϕ). The data were collected with the CMS detector, at the LHC. A broadening of the away-side (∆ϕ ≈ π) azimuthal correlation is observed at all ∆η, as compared to the measurements ...Journal Article -
Search for large extra dimensions in the diphoton final state at the Large Hadron Collider
(2011)Journal of High Energy PhysicsA search for large extra spatial dimensions via virtual-graviton exchange in the diphoton channel has been carried out with the CMS detector at the LHC. No excess of events above the standard model expectations is found using a data sample collected in proton-proton collisions at s√=7 TeV and corresponding to an integrated luminosity of 36 pb− 1. New lower limits on the effective Planck scale in the range of 1.6–2.3TeV at the 95% confidence ...Journal Article -
Search for same-sign top-quark pair production at √s=7 TeV and limits on flavour changing neutral currents in the top sector
(2011)Journal of High Energy PhysicsAn inclusive search for same-sign top-quark pair production in pp collisions at s√=7 TeV is performed using a data sample recorded with the CMS detector in 2010, corresponding to an integrated luminosity of 35 pb−1. This analysis is motivated by recent studies of pp¯→tt¯ reporting mass-dependent forward-backward asymmetries larger than expected from the standard model. These asymmetries could be due to Flavor Changing Neutral Currents ...Journal Article -
Measurement of the differential cross section for isolated prompt photon production in pp collisions at 7 TeV
(2011)Physical Review DA measurement of the differential cross section for the inclusive production of isolated prompt photons in proton-proton collisions at a center-of-mass energy of 7 TeV is presented. The data sample corresponds to an integrated luminosity of 36 pb−1 recorded by the CMS detector at the LHC. The measurement covers the pseudorapidity range |η|<2.5 and the transverse energy range 25<ET<400 GeV, corresponding to the kinematic region 0.007<xT<0.114. ...Journal Article -
Charged particle multiplicities in pp interactions at √s=0.9 , 2.36, and 7 TeV
(2011)Journal of High Energy PhysicsMeasurements of primary charged hadron multiplicity distributions are presented for non-single-diffractive events in proton-proton collisions at centre-of-mass energies of s√=0.9, 2.36, and 7 TeV, in five pseudorapidity ranges from |η| < 0.5 to |η| < 2.4. The data were collected with the minimum-bias trigger of the CMS experiment during the LHC commissioning runs in 2009 and the 7 TeV run in 2010. The multiplicity distribution at s√=0.9TeV ...Journal Article -
Search for resonances in the dilepton mass distribution in pp collisions at √s=7 TeV
(2011)Journal of High Energy PhysicsA search for narrow resonances at high mass in the dimuon and dielectron channels has been performed by the CMS experiment at the CERN LHC, using pp collision data recorded at s√=7 TeV. The event samples correspond to integrated luminosities of 40 pb−1 in the dimuon channel and 35 pb−1 in the dielectron channel. Heavy dilepton resonances are predicted in theoretical models with extra gauge bosons (Z′) or as Kaluza-Klein graviton excitations ...Journal Article -
Measurement of Bose-Einstein correlations in pp collisions at √s=0.9 and 7 TeV
(2011)Journal of High Energy PhysicsBose-Einstein correlations between identical particles are measured in samples of proton-proton collisions at 0.9 and 7 TeV centre-of-mass energies, recorded by the CMS experiment at the LHC. The signal is observed in the form of an enhancement of number of pairs of same-sign charged particles with small relative momentum. The dependence of this enhancement on kinematic and topological features of the event is studied. Anticorrelations ...Journal Article