First measurement of hadronic event shapes in pp collisions at s=7 TeV
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 699:1-2 (2011) 48-67
Abstract:
Hadronic event shapes have been measured in proton-proton collisions at s=7 TeV, with a data sample collected with the CMS detector at the LHC. The sample corresponds to an integrated luminosity of 3.2 pb-1. Event-shape distributions, corrected for detector response, are compared with five models of QCD multijet production. © 2011 CERN.Measurement of W+W-production and search for the Higgs boson in pp collisions at √s=7 TeV
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 699:1-2 (2011) 25-47
Abstract:
A measurement of W + W - production in pp collisions at √s=7 TeV and a search for the Higgs boson are reported. The W + W - candidates are selected in events with two leptons, either electrons or muons. The measurement is performed using LHC data recorded with the CMS detector, corresponding to an integrated luminosity of 36 pb -1 . The pp → W + W - cross section is measured to be 41.1±15.3(stat)±5.8(syst)±4.5(lumi)pb, consistent with the standard model prediction. Limits on WWγ and WWZ anomalous triple gauge couplings are set. The search for the standard model Higgs boson in the W + W - decay mode does not reveal any evidence of excess above backgrounds. Limits are set on the production of the Higgs boson in the context of the standard model and in the presence of a sequential fourth family of fermions with high masses. In the latter context, a Higgs boson with mass between 144 and 207 GeV/c2 is ruled out at 95% confidence level. © 2011 CERN.Invariant mass distribution of jet pairs produced in association with a W boson in pp collisions at sqrt[s]=1.96 TeV.
Phys Rev Lett 106:17 (2011) 171801
Abstract:
We report a study of the invariant mass distribution of jet pairs produced in association with a W boson using data collected with the CDF detector which correspond to an integrated luminosity of 4.3 fb(-1). The observed distribution has an excess in the 120-160 GeV/c(2) mass range which is not described by current theoretical predictions within the statistical and systematic uncertainties. In this Letter, we report studies of the properties of this excess.Measurement of the top quark mass in the lepton+jets channel using the lepton transverse momentum
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 698:5 (2011) 371-379
Abstract:
This Letter reports a measurement of the top quark mass, Mtop, in data from pp- collisions at s=1.96 TeV corresponding to 2.7 fb-1 of integrated luminosity at the Fermilab Tevatron using the CDF II detector. Events with the lepton+jets topology are selected. An unbinned likelihood is constructed based on the dependence of the lepton transverse momentum, PT, on Mtop. A maximum likelihood fit to the data yields a measured mass Mtop=176.9±8.0stat±2.7syst GeV/c2. In this measurement, the contribution by the jet energy scale uncertainty to the systematic error is negligible. The result provides an important consistency test for other Mtop measurements where explicit use of the jet energy is made for deriving the top quark mass. © 2011 Elsevier B.V.Measurement of the Polarization of W Bosons with Large Transverse Momenta in W+Jets Events at the LHC
ArXiv 1104.3829 (2011)