Jet production rates in association with W and Z bosons in pp collisions at √s = 7 TeV
Journal of High Energy Physics 2012:1 (2012)
Abstract:
Measurements of jet production rates in association with W and Z bosons for jet transverse momenta above 30 GeV are reported, using a sample of proton-proton collision events recorded by CMS at √s = 7TeV, corresponding to an integrated luminosity of 36 pb-1. The study includes the measurement of the normalized inclusive rates of jets σ(V+ ≥ n jets)=σ(V), where V represents either a W or a Z. In addition, the ratio of W to Z cross sections and the W charge asymmetry as a function of the number of associated jets are measured. A test of scaling at √s = 7TeV is also presented. The measurements provide a stringent test of perturbative-QCD calculations and are sensitive to the possible presence of new physics. The results are in agreement with the predictions of a simulation that uses explicit matrix element calculations for final states with jets. © 2012 SISSA.Measurement of CP-violating asymmetries in D0→π+π- and D0→K+K- decays at CDF
Physical Review D American Physical Society (APS) 85:1 (2012) 012009
Measurement of the Z/γ*+b-jet cross section in pp collisions at √s = 7 TeV
Journal of High Energy Physics 2012:6 (2012)
Abstract:
The production of b jets in association with a Z/γ*boson is studied using proton-proton collisions delivered by the LHC at a centre-of-mass energy of 7TeV and recorded by the CMS detector. The inclusive cross section for Z/γ*+b-jet production is measured in a sample corresponding to an integrated luminosity of 2.2 fb-1. The Z/γ*+b-jet cross section with Z/γ*→ℓℓ (where ℓ ℓ = ee or μ μ) for events with the invariant mass 60 < Mℓ ℓ < 120 GeV, at least one b jet at the hadron level with pT > 25 GeV and |η|< 2:1, and a separation between the leptons and the jets of ΔR > 0:5 is found to be 5:84±0:08 (stat:) ±0:72 (syst:) -0:55+0:25 (theory) pb. The kinematic properties of the events are also studied and found to be in agreement with the predictions made by the MadGraph event generator with the parton shower and the hadronisation performed by pythia.Measurement of the cross section for production of bb̄X decaying to muons in pp collisions at √ s = 7 TeV
Journal of High Energy Physics 2012:6 (2012)
Abstract:
A measurement of the inclusive cross section for the process pp → bb̄X → μμX′ at √ s = 7TeV is presented, based on a data sample corresponding to an integrated luminosity of 27.9 pb-1 collected by the CMS experiment at the LHC. By selecting pairs of muons each with pseudorapidity |η| < 2:1, the value σ(pp → bb̄X → μμX′) = 26:4 ± 0:1 (stat.) ±2:4 (syst.) ±1:1 (lumi.) nb is obtained for muons with transverse momentum pT > 4 GeV, and 5:12±0:03 (stat.) ±0:48 (syst.) ±0:20 (lumi.) nb for pT > 6 GeV. These results are compared to QCD predictions at leading and next-to-leading orders.Measurement of the inclusive production cross sections for forward jets and for dijet events with one forward and one central jet in pp collisions at √s = 7 TeV
Journal of High Energy Physics 2012:6 (2012)