Search for Wbb̄ and W H production in pp̄ collisions at √s = 1.96 TeV
Physical Review Letters 94:9 (2005)
Abstract:
We present a search for Wbb̄ production in pp̄ collisions at √s = 1.96 TeV in events containing one electron, an imbalance in transverse momentum, and two b-tagged jets. Using 174 pb-1 of integrated luminosity accumulated by the D0 experiment at the Fermilab Tevatron collider, and the standard-model description of such events, we set a 95% C.L. upper limit on Wbb̄ production of 6.6 pb for b quarks with transverse momenta pTb > 20 GeV and bb̄ separation in pseudorapidity-azimuth space δRbb > 0.75. Restricting the search to optimized bb̄ mass intervals provides upper limits on WH production of 9.0-12.2 pb for Higgs-boson masses of 105-135 GeV. © 2005 The American Physical Society.Erratum: Measurement of the W boson polarization in top decay at CDF at √s p = 1:8 TeV (Physical Review D (2005) 71 (031101))
Physical Review D - Particles, Fields, Gravitation and Cosmology 71:5 (2005) 1-2
Measurement of the forward-backward charge asymmetry from W→ev production in pp̄ collisions at √s=1.96 TeV
Physical Review D - Particles, Fields, Gravitation and Cosmology 71:5 (2005) 1-9
Abstract:
We report a measurement of the forward-backward charge asymmetry of electrons from W boson decays in pp̄ collisions at √s=1.96 TeV using a data sample of 170 pb-1 collected by the Collider Detector at Fermilab. The asymmetry is measured as a function of electron rapidity and transverse energy and provides new input on the momentum fraction dependence of the u and d quark parton distribution functions within the proton. © 2005 The American Physical Society.Measurement of the moments of the hadronic invariant mass distribution in semileptonic B decays
Physical Review D - Particles, Fields, Gravitation and Cosmology 71:5 (2005) 1-9
Abstract:
Using 180 pb -1 of data collected with the CDF II detector at the Tevatron, we measure the first two moments of the hadronic invariant mass-squared distribution in charmed semileptonic B decays. From these we determine the nonperturbative Heavy Quark Effective Theory parameters Λ and λ 1 used to relate the B meson semileptonic branching ratio to the CKM matrix element |V cb|. For a minimum lepton momentum of 0.7 GeV/c in the B rest frame we measure the first two moments of the D** → D (*)π component to be 〈m D**2〉 = (5.83 ± 0.16 stat ± 0.08 syst) GeV 2/c 4 and 〈(m D**2 - 〈m D**2〉) 2〉 = (1.30 ± 0.69 stat ± 0.22 syst) GeV 4/c 8. Combining these with the discrete mass terms from the D and D* mesons, we find the total moments to be 〈M Ξc2〉 - m̄ D2 = (0.467 ± 0.038 stat ± 0.068 syst GeV 2/c 4 and 〈(M Ξc2 - 〈M Ξc2〉) 2〉 = (1.05 ± 0.26 stat ± 0.13 syst) GeV 4/c 8, where m̄ D is the spin-averaged D mass. The systematic error is dominated by the uncertainties in the world-average branching ratios used to combine the D, D*, and D** contributions. The analysis makes no assumptions about the shape or resonant structure of the D** → D (*)π invariant mass distribution. © 2005 The American Physical Society.Measurement of the tt̄ production cross section in pp̄ collisions at √s = 1.96 TeV using lepton + jets events with secondary vertex b -tagging
Physical Review D - Particles, Fields, Gravitation and Cosmology 71:5 (2005) 1-28