Measuring the CKM Matrix Element Vtb at DZero and CDF

I present measurements by the CDF collaboration of the Standard Model three generation CKM matrix element Vtb and of a special case extension with additional assumptions, using current Tevatron ttbar data. I then show how we can significantly improve the precision on Vtb and at the same time extend the measurement so it is not constrained by Standard Model assumptions, using single top production at the upgraded Tevatron.Comment: 8 pages. To appear in the proceedings of the 2nd International Conference on B Physics and CP Violation, Honolulu, Hawaii, March 199

Recent Results on the Top Quark from the Tevatron Collider Experiments

This paper presents the latest measurements of the properties of the top quark as determined by the DZero and CDF collaborations at the Fermilab Tevatron ppbar collider. Both experiments have studied the all-hadronic decay mode of ttbar events. The top quark measurement has been refined over the past year, with the addition of new channels and a re-evaluation of some of the earlier ones. There are recent studies of the mass of the ttbar system, the helicity of the W bosons in the top quark decays, and of the correlation of the spins of the top and antitop quarks. New results are also reported on searches for charged Higgs bosons in top quark decay, and for electroweak production of single top quarks.Comment: 10 pages, 13 figures. To appear in the proceedings of the XXXIVth Rencontres de Moriond, Electroweak Interactions and Unified Theories, Les Arcs, Savoie, France, (March 1999

Future Top Physics at the Tevatron and LHC

Top quarks are produced at the Tevatron proton-antiproton collider at Fermilab and at the Large Hadron (proton-proton) Collider at CERN in two ways: as quark-antiquark pairs, and singly. For each mode, the cross sections and future experimental yields are presented. I then discuss some precision measurements that can be made using the anticipated large data sets. These measurements include the top quark mass, width and branching fractions, the electroweak Wtb coupling, and the CKM matrix element Vtb. Detailed studies of the top quark polarization and gluon radiation will also be possible, in addition to sensitive searches for ttbar resonances and rare decay modes.Comment: 10 pages, 8 tables. Talk given at the XXXIst Rencontres de Moriond, QCD and High Energy Hadronic Interactions, Les Arcs, Savoie, France, 23rd-30th March 199

Search for Electroweak Production of Single Top Quarks at DZero

This paper discusses a search for electroweak production of single top quarks in the electron+jets and muon+jets decay channels. The measurements use ~90 pb^-1 of data from Run 1 of the Fermilab Tevatron collider, collected at 1.8 TeV with the DZero detector. We use events that include a tagging muon, implying the presence of a b jet, to set an upper limit at the 95% confidence level on the cross section for the s-channel process ppbar->tb+X of 39 pb. The upper limit for the t-channel process ppbar->tqb+X is 58 pb

Single top quarks at the Fermilab Tevatron

We present a calculation of the single top quark cross section for proton-antiproton interactions with sqrt(s) = 1.8 TeV at the Fermilab Tevatron collider. We examine the effects of top mass, parton distribution functions, QCD scale, and collision energy, on each of the component production mechanisms, and study the kinematic distributions for standard model electroweak production. At the upgraded Tevatron with sqrt(s) = 2.0 TeV and high luminosity, it will be possible to test the nature of the Wtb coupling using single top production. We estimate the sensitivity to measure the single top cross section, and thus to directly measure V_tb and the top quark partial width. We show what happens to the V_tb measurement when an anomalous (V+A) component is added to the Wtb coupling, and how the top quark polarization affects the kinematic distributions.Comment: 31 pages including 11 figure