Search
Results
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Measurement of the ratio of inclusive jet cross sections using the anti-kT algorithm with radius parameters R=0.5 and 0.7 in pp collisions at √s=7 TeV
(2014)Physical Review DMeasurements of the inclusive jet cross section with the anti-kT clustering algorithm are presented for two radius parameters, R=0.5 and 0.7. They are based on data from LHC proton-proton collisions at √s=7 TeV corresponding to an integrated luminosity of 5.0 fb−1 collected with the CMS detector in 2011. The ratio of these two measurements is obtained as a function of the rapidity and transverse momentum of the jets. Significant ...Journal Article -
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 -
Measurement of the ratio B(t→Wb)/B(t→Wq) in pp collisions at √s = 8 TeV
(2014)Physics Letters BThe ratio of the top-quark branching fractions R = B(t --> Wb)/B(t --> Wq), where the denominator includes the sum over all down-type quarks (q = b, s, d), is measured in the t (t) over bar dilepton final state with proton-proton collision data at root s = 8 TeV from an integrated luminosity of 19.7 fb(-1), collected with the CMS detector. In order to quantify the purity of the signal sample, the cross section is measured by fitting the ...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 -
Searches for electroweak production of charginos, neutralinos, and sleptons decaying to leptons and W, Z, and Higgs bosons in pp collisions at 8 TeV
(2014)The European Physical Journal CSearches for the direct electroweak production of supersymmetric charginos, neutralinos, and sleptons in a variety of signatures with leptons and W, Z, and Higgs bosons are presented. Results are based on a sample of proton-proton collision data collected at center-of-mass energy s√=8TeV with the CMS detector in 2012, corresponding to an integrated luminosity of 19.5 fb-1. The observed event rates are in agreement with expectations from ...Journal Article -
Evidence of b -Jet Quenching in PbPb Collisions at √sNN =2.76 TeV
(2014)Physical Review LettersThe production of jets associated to bottom quarks is measured for the first time in PbPb collisions at a center-of-mass energy of 2.76 TeV per nucleon pair. Jet spectra are reported in the transverse momentum (pT) range of 80-250GeV/c, and within pseudorapidity |η|<2. The nuclear modification factor (RAA) calculated from these spectra shows a strong suppression in the b-jet yield in PbPb collisions relative to the yield observed in pp ...Journal Article -
Search for anomalous production of events with three or more leptons in pp collisions at √s = 8 TeV
(2014)Physical Review DA search for physics beyond the standard model in events with at least three leptons is presented. The data sample, corresponding to an integrated luminosity of 19.5 fb−1 of proton-proton collisions with center-of-mass energy √s = 8 TeV, was collected by the CMS experiment at the LHC during 2012. The data are divided into exclusive categories based on the number of leptons and their flavor, the presence or absence of an opposite-sign, ...Journal Article -
Measurement of WZ and ZZ production in pp collisions at √s = 8TeV in final states with b-tagged jets
(2014)The European Physical Journal CMeasurements are reported of the WZ and ZZ production cross sections in proton-proton collisions at s√=8 TeV in final states where one Z boson decays to b-tagged jets. The other gauge boson, either W or Z, is detected through its leptonic decay (either W→eν, μν or Z→e+e−, μ+μ−, or νν¯¯¯). The results are based on data corresponding to an integrated luminosity of 18.9 fb−1 collected with the CMS detector at the Large Hadron Collider. The ...Journal Article -
Search for invisible decays of Higgs bosons in the vector boson fusion and associated ZH production modes
(2014)The European Physical Journal CA search for invisible decays of Higgs bosons is performed using the vector boson fusion and associated ZH production modes. In the ZH mode, the Z boson is required to decay to a pair of charged leptons or a bb¯¯¯ quark pair. The searches use the 8┬áTeV pp collision dataset collected by the CMS detector at the LHC, corresponding to an integrated luminosity of up to 19.7┬áfb−1. Certain channels include data from 7┬áTeV collisions corresponding ...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