Measurements of direct CP violating asymmetries in charmless decays of strange bottom mesons and bottom baryons.
Phys Rev Lett 106:18 (2011) 181802
Abstract:
We report measurements of direct CP-violating asymmetries in charmless decays of neutral bottom hadrons to pairs of charged hadrons with the upgraded Collider Detector at the Fermilab Tevatron. Using a data sample corresponding to 1 fb(-1) of integrated luminosity, we obtain the first measurements of direct CP violation in bottom strange mesons, A(CP)(B(s)(0)→K(-)π(+))=+0.39±0.15(stat)±0.08(syst), and bottom baryons, A(CP)(Λ(b)(0)→pπ(-))=+0.03±0.17(stat)±0.05(syst) and A(CP)(Λ(b)(0)→pK(-))=+0.37±0.17(stat)±0.03(syst). In addition, we measure CP violation in B(0)→K(+)π(-) decays with 3.5σ significance, A(CP)(B(0)→K(+)π(-))=-0.086±0.023(stat)±0.009(syst), in agreement with the current world average. Measurements of branching fractions of B(s)(0)→K(+)K(-) and B(0)→π(+)π(-) decays are also updated.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