Jeff Tseng

Abstract:

This report provides a comprehensive overview of the prospects for B physics at the Tevatron. The work was carried out during a series of workshops starting in September 1999. There were four working groups: 1) CP Violation, 2) Rare and Semileptonic Decays, 3) Mixing and Lifetimes, 4) Production, Fragmentation and Spectroscopy. The report also includes introductory chapters on theoretical and experimental tools emphasizing aspects of B physics specific to hadron colliders, as well as overviews of the CDF, D0, and BTeV detectors, and a Summary.

Abstract:

We present a measurement of the cross section and the first measurement of the heavy flavor content of associated direct photon + muon events produced in hadronic collisions. These measurements come from a sample of 1.8 TeV pp̄ collisions recorded with the Collider Detector at Fermilab. Quantum chromodynamics (QCD) predicts that these events are primarily due to the Compton scattering process cg→cγ, with the final-state charm quark producing a muon. The cross section for events with a photon transverse momentum between 12 and 40 GeV/c is measured to be 46.8±6.3±7.5 pb, which is two standard deviations below the most recent theoretical calculation. A significant fraction of the events in the sample contain a final-state bottom quark. The ratio of charm to bottom production is measured to be 2.4±1.2, in good agreement with QCD models.

Abstract:

The inclusive cross section for J/Ψ production times the branching ratio B(J/Ψ→μ + μ - ) has been measured in the forward pseudorapidity region: B×dσ[p - +p→J/Ψ(p T >10 GeV/c,2.1<|η|<2.6)+X]/dη = 192±9(stat) ±29(syst) pb. The results are based on 74.1±5.2 pb -1 of data collected by the CDF Collaboration at the Fermilab Tevatron Collider. The measurements extend earlier measurements of the D0 Collaboration to higher p TJ/Ψ . In the kinematic range where the experiments partially overlap, these data are in good agreement with previous measurements.

Abstract:

We present measurements of the B+meson total cross section and differential cross section dσ/dpT. The measurements use a 98±4 pb-1sample of pp̄ collisions at √s=1.8 TeV collected by the CDF detector. Charged B meson candidates are reconstructed through the decay B±→J|ψ±with J|ψ→µ+µ-. The total cross section, measured in the central rapidity region |y|<1.0 for pT(B)>6.0 GeV/c, is 3.6±0.6(stat ⊕ syst) µb. The measured differential cross section is substantially larger than typical QCD predictions calculated to next-to-leading order.

Abstract:

We report a measurement of the ratio of the bottom quark production cross section in antiproton-proton collisions at (Formula Presented)=630 GeV to 1800 GeV using bottom quarks with transverse momenta greater than 10.75 GeV identified through their semileptonic decays and long lifetimes. The measured ratio σ(630)/ σ(1800) 50.171±.024±.012 is in good agreement with next-to-leading order quantum chromodynamics.