Related papers: Spin Issues in t-tbar Production and Decay
We describe the implementation of top production and decay processes in the parton-level Monte Carlo program MCFM. By treating the top quark as being on-shell, we can factorize the amplitudes for top-pair production, s-channel single-top…
Top quark pair production at proton-antiproton colliders is known to exhibit a forward-backward asymmetry due to higher-order QCD effects. We explore how this asymmetry might be studied at the Fermilab Tevatron, including how the asymmetry…
Spin correlations between top-quark and anti-top-quark in pair production are sensitive to physics beyond the standard model. A complete set of observables, that can be used to measure all independent parameters of the production spin…
We review the search for the top quark conducted by the D-Zero collaboration using data from the Fermilab pbar-p collider. Based upon a preliminary analysis of an integrated luminosity of about 13.5 pb-1, we have searched for t-tbar…
Continuing earlier work, we examine the constraint on an anomalous t-c-g coupling from top quark decay. We find that from current CDF measurements of the branching ratio $t \rightarrow W b$, the minimum scale at which new physics can…
An overview of the recent measurements of the top quark properties in proton antiproton collisions at \sqrt{s}=1.96 TeV is presented.These measurements are based on 5.4 -- 8.7 fb^-1 of data collected with the D0 and CDF experiments at the…
We examine loop-mediated effects of new heavy quarks Q=(t',b') on t tbar production at hadron colliders, using a phenomenological model with flavor off-diagonal couplings of charged and neutral scalars phi=(phi^+-,phi^0) to Q. We show that…
The production of top-antitop pairs at the Fermilab Tevatron shows a forward-backward asymmetry in which the top quark tends to follow the proton direction, while the antitop tends to follow the antiproton direction. The effect grows with…
Single production of top quarks at hadron colliders via $gW$ fusion is examined as a probe of possible anomalous chromomagnetic and/or chromoelectric moment type couplings between the top and gluons. We find that this channel is far less…
In this article, I review recent measurements of the production of the top quark in $p\bar p$ collisions at a centre-of-mass energy of $\sqrt s=1.96$~TeV in Run II of the Fermilab Tevatron Collider, recorded by the CDF and D0…
Angular distribution of a secondary particle from top-quark decays is studied in a simple and general manner, paying careful attention to how relevant the top-quark production mechanism is. The conditions that lead to the distribution free…
I review the latest results on properties of the top quark from the Tevatron and the LHC, including results measured in $t\bar{t}$ and single-top events on the mass, width, couplings, and spin correlations.
We present an analysis of top-antitop quark production and decay into a tau lepton, tau neutrino, and bottom quark using data from $9 {\rm fb}^{-1}$ of integrated luminosity at the Collider Detector at Fermilab. Dilepton events, where one…
In terms of an effective Lagrangian we investigate the possibilities of probing anomalous top quark couplings, $t \bar{t} H$, $\gamma t \bar{t}$, $Z t \bar{t}$ and $tWb$ at the future linear colliders. It is found that probing anomalous top…
We recently proposed that, due to the top-quark-mass enhanced Yukawa coupling, the s-channel production of a charged scalar or pseudo-scalar from heavy quark fusion can be an important new mechanism for discovering non-standard spin-0…
A long time ago, at a laboratory far, far away, the Fermilab Tevatron collided protons and antiprotons at $\sqrt{s} = 1.96$ TeV. The CDF and D0 experiments each recorded datasets of about 10 fb$^{-1}$. As such experiments may never be…
The CDF and D0 collaborations at Fermilab's Tevatron p-pbar collider have in place an extensive program to measure fundamental properties of the top quark. Recent results from Run I (sqrt-s = 1.8 TeV) and Run II (sqrt-s = 1.96 TeV) on the…
The single transverse spin asymmetries in heavy quark and anti-quark production from the quark-antiquark annihilation channel contribution is studied by taking into account the initial and final state interactions effects. Because of the…
Measurements of top quark spin observables in $t\bar{t}$ events are presented based on 20.2 fb$^{-1}$ of $\sqrt{s} = 8$ TeV proton-proton collisions recorded with the ATLAS detector at the LHC. The analysis is performed in the dilepton…
The top quark antiquark production system in the dilepton decay channel is described by a set of equations which is nonlinear in the unknown neutrino momenta. Its most precise and least time consuming solution is of major importance for…