First simultaneous measurement of the top quark mass in the lepton+jets and dilepton channels at CDF
Physical Review D - Particles, Fields, Gravitation and Cosmology 79:9 (2009)
Abstract:
We present a measurement of the mass of the top quark using data corresponding to an integrated luminosity of 1.9fb-1 of pp̄ collisions collected at s=1.96TeV with the CDF II detector at Fermilab's Tevatron. This is the first measurement of the top quark mass using top-antitop pair candidate events in the lepton+jets and dilepton decay channels simultaneously. We reconstruct two observables in each channel and use a nonparametric kernel density estimation technique to derive two-dimensional probability density functions from simulated signal and background samples. The observables are the top quark mass and the invariant mass of two jets from the W decay in the lepton+jets channel, and the top quark mass and the scalar sum of transverse energy of the event in the dilepton channel. We perform a simultaneous fit for the top quark mass and the jet energy scale, which is constrained in situ by the hadronic W boson mass. Using 332 lepton+jets candidate events and 144 dilepton candidate events, we measure the top quark mass to be Mtop=171.9±1. 7(stat+JES)±1.1(othersyst)GeV/c2=171.9±2.0GeV/c2. © 2009 The American Physical Society.Measurement of charged current deep inelastic scattering cross sections with a longitudinally polarised electron beam at HERA
European Physical Journal C 61:2 (2009) 223-235
Abstract:
Measurements of the cross sections for charged current deep inelastic scattering in e - p collisions with longitudinally polarised electron beams are presented. The measurements are based on a data sample with an integrated luminosity of 175 pb-1 collected with the ZEUS detector at HERA at a centre-of-mass energy of 318 GeV. The total cross section is given for positively and negatively polarised electron beams. The differential cross-sections d σ/dQ 2, d σ/dx and d σ/dy are presented for Q 2>200 GeV2. The double-differential cross-section d 2 σ/dxdQ 2 is presented in the kinematic range 2802<30∈000 GeV2 and 0.015
Measurement of the b-hadron production cross section using decays to μ-D0X final states in pp̄ collisions at s=1.96TeV
Physical Review D - Particles, Fields, Gravitation and Cosmology 79:9 (2009)
Abstract:
We report a measurement of the production cross section for b hadrons in pp̄ collisions at s=1.96TeV. Using a data sample derived from an integrated luminosity of 83pb-1 collected with the upgraded Collider Detector (CDF II) at the Fermilab Tevatron, we analyze b hadrons, Hb, partially reconstructed in the semileptonic decay mode Hb→μ-D0X. Our measurement of the inclusive production cross section for b hadrons with transverse momentum pT>9GeV/c and rapidity |y|<0.6 is σ=1.30μb±0.05μb(stat)±0. 14μb(syst)±0.07μb(B), where the uncertainties are statistical, systematic, and from branching fractions, respectively. The differential cross sections dσ/dpT are found to be in good agreement with recent measurements of the Hb cross section and well described by fixed-order next-to-leading logarithm predictions. © 2009 The American Physical Society.Measurement of charm and beauty production in deep inelastic ep scattering from decays into muons at HERA
ArXiv 0904.3487 (2009)
Scaled momentum distributions of charged particles in dijet photoproduction at HERA
ArXiv 0904.3466 (2009)