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Measurement of the differential and double-differential Drell-Yan cross sections in proton-proton collisions at s √ = 7 TeV
(2013)Journal of High Energy PhysicsMeasurements of the differential and double-differential Drell-Yan cross sections are presented using an integrated luminosity of 4.5 (4.8) fb−1 in the dimuon (dielectron) channel of proton-proton collision data recorded with the CMS detector at the LHC at s√ = 7 TeV. The measured inclusive cross section in the Z-peak region (60–120 GeV) is σ(ℓℓ) = 986.4 ± 0.6 (stat.) ± 5.9 (exp. syst.) ± 21.7 (th. syst.) ± 21.7 (lum.) pb for the combination ...Journal Article -
Measurement of the tt ¯ production cross section in the all-jet final state in pp collisions at s √ =7 TeV
(2013)Journal of High Energy PhysicsA measurement is presented of the tt¯ production cross section (σtt¯) in proton-proton collisions at a centre-of-mass energy of 7 TeV, in the all-jet final state that contains at least six jets, two of which are tagged as originating from b quarks. The data correspond to an integrated luminosity of 3.54 fb−1, collected with the CMS detector at the LHC. The cross section is determined through an unbinned maximum likelihood fit of background ...Journal Article -
Erratum: search for new physics in events with same-sign dileptons and b jets in pp collisions at √s=8 TeV (Journal of High Energy Physics)
(2013)Journal of High Energy PhysicsJournal Article -
Measurement of the W-boson helicity in top-quark decays from tt̅ production in lepton+jets events in pp collisions at √s= 7 TeV
(2013)Journal of High Energy PhysicsThe W-boson helicity fractions in top-quark decays are measured with tt¯ events in the lepton+jets final state, using proton-proton collisions at a centre-of-mass energy of 7 TeV, collected in 2011 with the CMS detector at the LHC. The data sample corresponds to an integrated luminosity of 5.0 fb−1. The measured fractions of longitudinal, left-, and right-handed helicity are F 0 = 0.682 ± 0.030 (stat.) ± 0.033 (syst.), F L = 0.310 ± 0.022 ...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 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 -
Study of the underlying event at forward rapidity in pp collisions at √s =0.9,2.76, and 7 TeV
(2013)Journal of High Energy PhysicsThe underlying event activity in proton-proton collisions at forward pseudo-rapidity (−6.6 < η < −5.2) is studied with the CMS detector at the LHC, using a novel observable: the ratio of the forward energy density, dE/dη, for events with a charged-particle jet produced at central pseudorapidity (|η jet| < 2) to the forward energy density for inclusive events. This forward energy density ratio is measured as a function of the central jet ...Journal Article -
Inclusive search for supersymmetry using razor variables in pp collisions at √s=7 TeV
(2013)Physical Review LettersAn inclusive search is presented for new heavy particle pairs produced in √s=7 TeV proton-proton collisions at the LHC using 4.7±0.1 fb−1 of integrated luminosity. The selected events are analyzed in the 2D razor space of MR, an event-by-event indicator of the heavy particle mass scale, and R, a dimensionless variable related to the missing transverse energy. The third-generation sector is probed using the event heavy-flavor content. ...Journal Article -
Measurement of associated production of vector bosons and top quark-antiquark pairs in pp collisions at √s=7 TeV
(2013)Physical Review LettersThe first measurement of vector-boson production associated with a top quark-antiquark pair in proton-proton collisions at √s=7 TeV is presented. The results are based on a data set corresponding to an integrated luminosity of 5.0 fb−1, recorded by the CMS detector at the LHC in 2011. The measurement is performed in two independent channels through a trilepton analysis of t¯tZ events and a same-sign dilepton analysis of t¯tV (V=W or Z) ...Journal Article