Search
Results
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Observation of a new boson with mass near 125 GeV in pp collisions at √s=7 and 8 TeV
(2013)Journal of High Energy PhysicsA detailed description is reported of the analysis used by the CMS Collaboration in the search for the standard model Higgs boson in pp collisions at the LHC, which led to the observation of a new boson. The data sample corresponds to integrated luminosities up to 5.1 fb−1 at s√=7 TeV, and up to 5.3 fb−1 at s√=8 TeV. The results for five Higgs boson decay modes γγ, ZZ, WW, ττ, and bb, which show a combined local significance of 5 standard ...Journal Article -
Measurement of the cross section and angular correlations for associated production of a Z boson with b hadrons in pp collisions at s√= 7 TeV
(2013)Journal of High Energy PhysicsA study of proton-proton collisions in which two b hadrons are produced in association with a Z boson is reported. The collisions were recorded at a centre-of-mass energy of 7 TeVwith the CMS detector at the LHC, for an integrated luminosity of 5.2 fb−1. The b hadrons are identified by means of displaced secondary vertices, without the use of reconstructed jets, permitting the study of b-hadron pair production at small angular separation. ...Journal Article -
Studies of jet mass in dijet and W/Z + jet events
(2013)Journal of High Energy PhysicsInvariant mass spectra for jets reconstructed using the anti-k T and CambridgeAachen algorithms are studied for different jet “grooming” techniques in data corresponding to an integrated luminosity of 5 fb−1, recorded with the CMS detector in proton-proton collisions at the LHC at a center-of-mass energy of 7 TeV. Leading-order QCD predictions for inclusive dijet and W/Z+jet production combined with parton-shower Monte Carlo models are ...Journal Article -
Search for narrow resonances and quantum black holes in inclusive and b-tagged dijet mass spectra from pp collisions at √s =7 TeV
(2013)Journal of High Energy PhysicsA search for narrow resonances and quantum black holes is performed in inclusive and b-tagged dijet mass spectra measured with the CMS detector at the LHC. The data set corresponds to 5 fb−1 of integrated luminosity collected in pp collisions at s√=7 TeV. No narrow resonances or quantum black holes are observed. Model-independent upper limits at the 95% confidence level are obtained on the product of the cross section, branching fraction ...Journal Article -
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 -
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