Single Top Production and Top Properties at the Tevatron

We summarize recent measurements made at the Tevatron Collider using top event candidates. Cross section and mass measurements are discussed in a separate contribution to these Proceedings. Here we report on studies of the top P$_T$ distribution in \ttbar production and studies of single top production. Properties of top decays examined are: BF(t \into Wb)/BF(t \into Wq), helicity amplitudes of W's from top decays and correlations of \ttbar decay products. Searches for new physics in rare top decays and a search for a state X \into \ttbar are also reported.Comment: 19 pages including 9 figures. Proceedings of the 1999 Lathuile Conferenc

Top decays and mass with CDF

The authors report preliminary results on top quark decays and measurements of the top mass recently obtained by the CDF collaboration, using a data sample of about 110 pb{sup {minus}1} collected at the Tevatron collider. Upper limits for non Standard model top decays into W + q (non b quark), Z + q and {gamma} + q are given. Top mass measurements are obtained in three topologies for t{anti t} production and decay into W b: lepton + {ge} 4 jets, di-lepton and all hadronic final states. The most precise measurement is obtained in the lepton + {ge} 4 jets topology using 34 events which have at least one jet tagged by the SVX or SLT b-tagging algorithms and a good constrained kinematics fit

On the Interpretation of the Electroweak Precision Data

The recent precision electroweak data on $\Gamma^l, \bar s^2_W$ and $M_W/M_Z$ are compared with the tree-level and the dominant-fermion-loop as well as the full one-loop standard-model predictions. While the tree-level predictions are ruled out, the dominant-fermion-loop predictions, defined by using $\alpha (M^2_Z)\cong 1/128.9$ in the tree-level formulae, as well as the full one-loop predictions are consistent with the experimental data. Deviations from the dominant-fermion-loop predictions are quantified in terms of an effective Lagrangian containing three additional parameters which have a simple meaning in terms of $SU(2)$ symmetry violation. The effective Lagrangian yields the standard one-loop predictions for specific values of these parameters, which are determined by $m_t$ and $m_H$.Comment: Preprint BI-TP 93/46 (September 1993), to be published in Phys. Lett. B, LaTeX, 10 pages, (figures are not included

Precision measurements of the top quark mass from the Tevatron in the pre-LHC era

The top quark is the heaviest of the six quarks of the Standard Model. Precise knowledge of its mass is important for imposing constraints on a number of physics processes, including interactions of the as yet unobserved Higgs boson. The Higgs boson is the only missing particle of the Standard Model, central to the electroweak symmetry breaking mechanism and generation of particle masses. In this Review, experimental measurements of the top quark mass accomplished at the Tevatron, a proton-antiproton collider located at the Fermi National Accelerator Laboratory, are described. Topologies of top quark events and methods used to separate signal events from background sources are discussed. Data analysis techniques used to extract information about the top mass value are reviewed. The combination of several most precise measurements performed with the two Tevatron particle detectors, CDF and \D0, yields a value of \Mt = 173.2 \pm 0.9 GeV/$c^2$.Comment: This version contains the most up-to-date top quark mass averag

The Values of mtm_t and αsˉ\bar{\alpha_s} Derived from the Non-Observation of Electroweak Radiative Corrections at LEP: Global Fit

A set of equations representing the $W/Z$ mass ratio and various observables of $Z$ decays in terms of $\bar\alpha \equiv\alpha (m_Z)$, $G_{\mu}$, $m_Z$, $m_t$, $m_H$, $\bar\alpha_{s} \equiv\alpha_{s} (m_Z)$, $m_b$ and $m_\tau$ (all other fermion masses being neglected) are compared with the latest data of the four LEP detectors, which at the level of one standard deviation coincide with their Born values. Our global fit gives: $m_t = 161^{+ 15 +16}_{-16 -22} \bar\alpha_{s} = 0.119 \pm 0.006 \pm 0.002$, where the central values correspond to $m_H = 300$ GeV, the first errors are statistical and the second ones represent shifts of the central values corresponding to $m_H = 1000$ GeV($+$) and 60 GeV($-$). The predicted mass of the top is smaller than in the recent fits by 4 GeV. The {\it predicted} values of $m_W/m_Z$ and the LEP observables, based on the fitted values of $m_t$ and $\bar{\alpha}_s$, show a weak dependence on $m_H$ and differ by several {\it predicted} standard deviations from the corresponding Born values. The uncertainties of the predicted values and their deviations from the corresponding Born values determine the experimental accuracy required to observe electroweak radiative corrections.Comment: LaTex, 15 pages (including 3 figures as EPS files at the end

Determination of the Jet Energy Scale at the Collider Detector at Fermilab

A precise determination of the energy scale of jets at the Collider Detector at Fermilab at the Tevatron $p\bar{p}$ collider is described. Jets are used in many analyses to estimate the energies of partons resulting from the underlying physics process. Several correction factors are developed to estimate the original parton energy from the observed jet energy in the calorimeter. The jet energy response is compared between data and Monte Carlo simulation for various physics processes, and systematic uncertainties on the jet energy scale are determined. For jets with transverse momenta above 50 GeV the jet energy scale is determined with a 3% systematic uncertainty

Search for a Technicolor omega_T Particle in Events with a Photon and a b-quark Jet at CDF

If the Technicolor omega_T particle exists, a likely decay mode is omega_T -> gamma pi_T, followed by pi_T -> bb-bar, yielding the signature gamma bb-bar. We have searched 85 pb^-1 of data collected by the CDF experiment at the Fermilab Tevatron for events with a photon and two jets, where one of the jets must contain a secondary vertex implying the presence of a b quark. We find no excess of events above standard model expectations. We express the result of an exclusion region in the M_omega_T - M_pi_T mass plane.Comment: 14 pages, 2 figures. Available from the CDF server (PS with figs): http://www-cdf.fnal.gov/physics/pub98/cdf4674_omega_t_prl_4.ps FERMILAB-PUB-98/321-