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Description and performance of track and primary-vertex reconstruction with the CMS tracker akahashi
(2014)Journal of InstrumentationA description is provided of the software algorithms developed for the CMS tracker both for reconstructing charged-particle trajectories in proton-proton interactions and for using the resulting tracks to estimate the positions of the LHC luminous region and individual primary-interaction vertices. Despite the very hostile environment at the LHC, the performance obtained with these algorithms is found to be excellent. For tbar t events ...Journal Article -
Search for top-squark pairs decaying into Higgs or Z bosons in pp collisions at √s=8 TeV
(2014)Physics Letters BA search for supersymmetry through the direct pair production of top squarks, with Higgs (H) or Z bosons in the decay chain, is performed using a data sample of proton–proton collisions at √s = 8TeV collected in 2012 with the CMS detector at the LHC. The sample corresponds to an integrated luminosity of 19.5 fb−1. The search is performed using a selection of events containing leptons and bottom-quark jets. No evidence for a significant ...Journal Article -
Measurement of jet multiplicity distributions in tt production in pp collisions at √s = 7TeV
(2014)The European Physical Journal CThe normalised differential top quark-antiquark production cross section is measured as a function of the jet multiplicity in proton-proton collisions at a centre-of-mass energy of 7TeV at the LHC with the CMS detector. The measurement is performed in both the dilepton and lepton+jets decay channels using data corresponding to an integrated luminosity of 5.0fb−1. Using a procedure to associate jets to decay products of the top quarks, the ...Journal Article -
Search for jet extinction in the inclusive jet-pT spectrum from proton-proton collisions at √s= 8TeV
(2014)Physical Review DThe first search at the LHC for the extinction of QCD jet production is presented, using data collected with the CMS detector corresponding to an integrated luminosity of 10.7 fb−1 of proton-proton collisions at a center-of-mass energy of 8 TeV. The extinction model studied in this analysis is motivated by the search for signatures of strong gravity at the TeV scale (terascale gravity) and assumes the existence of string couplings in the ...Journal Article -
Measurement of jet fragmentation in PbPb and pp collisions at √sNN = 2.76 TeV
(2014)Physical Review CThe jet fragmentation function of inclusive jets with transverse momentum pT above 100GeV/c in PbPb collisions has been measured using reconstructed charged particles with pT above 1GeV/c in a cone of radius 0.3 around the jet axis. A data sample of PbPb collisions collected in 2011 at a nucleon-nucleon center-of-mass energy of √sNN=2.76TeV corresponding to an integrated luminosity of 150μb−1 is used. The results for PbPb collisions as a ...Journal Article -
Studies of dijet transverse momentum balance and pseudorapidity distributions in pPb collisions at √sNN = 5.02 TeV
(2014)The European Physical Journal CDijet production has been measured in pPb collisions at a nucleon–nucleon centre-of-mass energy of 5.02TeV. A data sample corresponding to an integrated luminosity of 35 nb−1 was collected using the Compact Muon Solenoid detector at the Large Hadron Collider. The dijet transverse momentum balance, azimuthal angle correlations, and pseudorapidity distributions are studied as a function of the transverse energy in the forward calorimeters ...Journal Article -
Measurement of four-jet production in proton-proton collisions at √s =7TeV
(2014)Physical Review DMeasurements of the differential cross sections for the production of exactly four jets in proton-proton collisions are presented as a function of the transverse momentum pT and pseudorapidity η, together with the correlations in azimuthal angle and the pT balance among the jets. The data sample was collected in 2010 at a center-of-mass energy of 7 TeV with the CMS detector at the LHC, with an integrated luminosity of 36 pb−1. The cross ...Journal Article -
Search for Top Squarks in R-Parity-Violating Supersymmetry Using Three or More Leptons and b-Tagged Jets
(2013)Physical Review LettersA search for anomalous production of events with three or more isolated leptons and bottom-quark jets produced in pp collisions at √s=8 TeV is presented. The analysis is based on a data sample corresponding to an integrated luminosity of 19.5 fb−1 collected by the CMS experiment at the LHC in 2012. No excess above the standard model expectations is observed. The results are interpreted in the context of supersymmetric models with ...Journal Article -
Searches for new physics using the tt ¯ invariant mass distribution in pp collisions at s √ =8 TeV
(2013)Physical Review LettersSearches for anomalous top quark-antiquark production are presented, based on pp collisions at √s=8 TeV. The data, corresponding to an integrated luminosity of 19.7 fb−1, were collected with the CMS detector at the LHC. The observed t¯t invariant mass spectrum is found to be compatible with the standard model prediction. Limits on the production cross section times branching fraction probe, for the first time, a region of parameter space ...Journal Article -
Search for supersymmetry in hadronic final states with missing transverse energy using the variables αT and b-quark multiplicity in pp collisions at √s=8 TeV
(2013)The European Physical Journal CAn inclusive search for supersymmetric processes that produce final states with jets and missing transverse energy is performed in pp collisions at a centre-of-mass energy of 8 TeV. The data sample corresponds to an integrated luminosity of 11.7 fb−1 collected by the CMS experiment at the LHC. In this search, a dimensionless kinematic variable, α T, is used to discriminate between events with genuine and misreconstructed missing transverse ...Journal Article