Rubin-LSST

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:

Using a 13.7 fb^-1 sample of continuum two-jet e ⁺e^- → qq̄ events collected with the CLEO detector, we have searched for correlations between Λ and Λ̄ particles, specifically in cases where the opening angle between the two particles is large and each has momentum > 1 GeV/c. Such correlations may indicate the presence of baryon number conservation at the primary quark level. A previous CLEO study of ΛcΛc correlations indicated direct, associated production of primary charmed baryons Λc: e⁺e^- → cc̄ → ΛcΛ̄c. That effect was not observed in Monte Carlo simulations. Our current search for similar direct, associated production of Λ baryons at the primary quark level (e⁺e ^- → ss̄ → ΛΛ̄, e.g.) qualitatively indicates a similar effect, although it relies on a Monte Carlo dependent subtraction of background ΛΛ̄ production (based on the default JETSET 7.4 event generator). © 2002 The American Physical Society.

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 T ^J/Ψ . In the kinematic range where the experiments partially overlap, these data are in good agreement with previous measurements.