Jeff Tseng

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.

Abstract:

The dilepton mass spectrum in pp-→|+|-+X interactions is studied using dielectrons (ee) and dimuons (μμ) in 100 pb- of data collected with the Collider Detector at Fermilab. The data are consistent with standard model predictions. The mass spectrum, being a probe for new physics, is examined for new interactions of quarks and leptons from a common composite structure. Assuming a contact interaction with the conventional coupling g20/4π = 1, limits on chiral quark-electron and quark-muon compositeness scales in the range of 2.5 to 4.2 TeV are obtained. © 1997 The American Physical Society.

Abstract:

This Letter describes a direct search for charged Higgs boson production in proton-antiproton collisions at sqrt(s)=1.8 TeV recorded by the Collider Detector at Fermilab. Two-Higgs-doublet extensions to the standard model predict the existence of charged Higgs bosons. In such models, the branching fraction for top quarks B(t → H b → tau nu b) can be large. This search uses the hadronic decays of the tau lepton in this channel to significantly extend previous limits on charged Higgs production. © 1997 The American Physical Society.

Abstract:

We have searched for heavy neutral gauge bosons (Z') in dielectron and dimuon decay modes using 110pb^-1 of p^-p collisions at √s = 1.8TeV collected with the Collider Detector at Fermilab. We present a limit on the production cross section times branching ratio of a Z' mass. For mass MZ' > 600 GeV/c², the upper limit is 40 fb at 95% confidence level. We set the lower mass limits of 690, 590, 620, 595, 565, 630, and 600 GeV/c² for Z'SM, ZΨ, Zψ, Zχ, ZI, ZLR, and ZALRM, respectively. © 1997 The American Physical Society.

Abstract:

We search for new particles that decay into b¯b and are produced with W bosons in p¯p collisions at √s = 1.8TeV. The search uses 109 ± 7pb^-1 accumulated by the CDF experiment at Fermilab. We select events with an eν or μν, and two jets, one of them b tagged. The number of events and the two-jet mass distribution are consistent with expectations. Using W+Higgs production as a model for the acceptance, we set an upper limit on the production cross section times branching ratio for the new particle ranging from 14 to 19 pb (95% C.L.) as the particle mass varies from 70 to 120GeV/c². © 1997 The American Physical Society.