Professor Daniela Bortoletto

Abstract:

We report the first observation of diffractively produced W bosons.In a sample of W → eν events produced in pp collisions at √s=1.8TeV, we find an excess of events with a forward rapidity gap, which is attributed to diffraction.The probability that this excess is consistent with nondiffractive production is 1.1×10−4 (3.8σ).The relatively low fraction of W+ jet events observed within this excess implies that mainly quarks from the Pomeron, which mediates diffraction, participate in W production.The diffractive to nondiffractive W production ratio is found to be RW=(1.15±0.55)%.© 1997 The American Physical Society.

Abstract:

We present measurements of correlated bb̄ cross sections, μ-μ, correlations, the average B0B̄0 mixing parameter χ̄, and a limit on the CP-violating parameter ∈B. For these measurements, we use muon pairs from bb double semileptonic decays. The data used in this analysis were taken with the Collider_Detector at Fermilab and represent an integrated luminosity of 17.4±0.6 pb-1. The results concerning bb̄ production correlations are compared to predictions of next-to-leading order QCD computations.