Measurement of the ratio of the 3-jet to 2-jet cross sections in pp collisions at s=7 TeV
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 702:5 (2011) 336-354
Abstract:
A measurement of the ratio of the inclusive 3-jet to 2-jet cross sections as a function of the total jet transverse momentum, HT, in the range 0.2Measurements of inclusive W and Z cross sections in pp collisions at √s = 7 TeV The CMS collaboration
Journal of High Energy Physics 2011:1 (2011)
Abstract:
Measurements of inclusive W and Z boson production cross sections in pp collisions at √s = 7 TeV are presented, based on 2.9 pb-1 of data recorded by the CMS detector at the LHC. The measurements, performed in the electron and muon decay channels, are combined to give σ(pp → WX) × B(W → l?) = 9.95 ± 0.07 (stat.) ± 0.28 (syst.) ± 1.09 (lumi.) nb and σ(pp → ZX) × B(Z → l +l-) = 0.931 ± 0.026 (stat.) ± 0.023 (syst.) ± 0.102 (lumi.) nb, where l stands for either e or μ. Theoretical predictions, calculated at the next-to-next-to-leading order in QCD using recent parton distribution functions, are in agreement with the measured cross sections. Ratios of cross sections, which incur an experimental systematic uncertainty of less than 4%, are also reported.Search for a heavy bottom-like quark in pp collisions at √s=7 TeV
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 701:2 (2011) 204-223
Abstract:
A search for pair-produced bottom-like quarks in pp collisions at √s=7 TeV is conducted with the CMS experiment at the LHC. The decay b'→tW is considered in this search. The b'b'→t∥W-t̄W+ process can be identified by the distinctive signature of trileptons and same-sign dileptons. With a data sample corresponding to an integrated luminosity of 34 pb-1, no excess above the standard model background predictions is observed and a b' quark with a mass between 255 and 361 GeV/c2 is excluded at the 95% confidence level. © 2011 CERN.Search for light resonances decaying into pairs of muons as a signal of new physics
Journal of High Energy Physics 2011:7 (2011)
Abstract:
A search for groups of collimated muons is performed using a data sample collected by the CMS experiment at the LHC, at a centre-of-mass energy of 7 TeV, and corresponding to an integrated luminosity of 35 pb-1. The analysis searches for production of new low-mass states decaying into pairs of muons and is designed to achieve high sensitivity to a broad range of models predicting leptonic jet signatures. With no excess observed over the background expectation, upper limits on the production cross section times branching fraction times acceptance are set, ranging from 0.1 to 0.5 pb at the 95% CL depending on event topology. In addition, the results are interpreted in several benchmark models in the context of supersymmetry with a new light dark sector exploring previously inaccessible parameter space.Search for new physics with jets and missing transverse momentum in pp collisions at √s = 7 TeV
Journal of High Energy Physics 2011:8 (2011)