Related papers: Top quark phenomenology
A number of top-spin observables are computed within the Standard Model (SM), at next-to-leading order in the strong and weak gauge couplings for hadronic top-quark anti-quark (ttbar) production and decay at the LHC for center-of-mass…
We consider the recent measurement of the top quark forward-backward asymmetry at the Fermilab Tevatron, which shows a discrepancy of slightly more than 2$\sigma$ compared to the SM prediction. We find that $t$-channel exchange of a color…
We consider the top quark charge asymmetry in the process $pp \to t\bar{t}+\gamma$ at the 13 TeV LHC. The genuine tree level asymmetry in the $q\bar{q}$ channel is large with about -12%. However, the symmetric $gg$ channel, photon radiation…
We report an evidence of \textit{s}-channel single top quark production in $p\bar{p}$ collision at $\sqrt{s}= 1.96 \mathrm{TeV}$ using data with integrated luminosity of $9.4 \mathrm{fb}^{-1}$ collected by the Collider Detector at Fermilab…
A sizeable difference in the differential production cross section of top- compared to antitop-quark production, denoted charge asymmetry, has been observed at the Tevatron. The experimental results seem to exceed the theory predictions…
Anomalous moments of the top quark arises from one loop corrections to the vertices $\bar t t g$ and $\bar t t \gamma$. We study these anomalous couplings in different frameworks: effective theories, Standard Model and 2HDM. We use…
The top quark plays an important role in the grand scheme of particle physics, and is also interesting on its own merits. We present recent results from CDF on top-quark physics based on 100-200/pb of p-pbar collision data. We have measured…
Past work has proven the possibility of extracting the top-quark mass, one of the fundamental parameters of the Standard Model, from the comparison of theory predictions and experimental measurements of differential cross-sections for…
A technique for separating top quark production from Standard Model background events is introduced. It is applicable to the channel in which one top quark decays semi-leptonically and its anti-quark decays hadronically into three jets, or…
The measurement of forward-backward asymmetry in the top and anti-top quark ($t \bar{t}$) production has been recently reconfirmed by the CDF Collaboration and shows a more than $3\sigma$ deviation from the Standard Model(SM) prediction in…
Recent CDF and D0 measurements of the top quark forward-backward asymmetry at the Tevatron present deviations between 1-sigma and 2-sigma from QCD predictions and a cut M_inv > 450 GeV on the events increases this deviation to 3.4 sigma in…
A first measurement of the top quark spin asymmetry, sensitive to the top quark polarisation, in t-channel single top quark production is presented. It is based on a sample of pp collisions at a centre-of-mass energy of 8 TeV corresponding…
The D0 experiment has searched for phenomena beyond the standard model in top quark events. The methods and results of four analyses covering various possible deviations from the standard model behaviour are discussed. With data sets…
The two Higgs doublet model for the top (T2HDM) is a 2HDM in which the top quark receives a special status, which endows it with a naturally large mass, and also gives rise to unique FC charged and neutral scalar interactions. We calculate…
The forward-backward asymmetry $A_{FB}^{t\bar t}$ in top quark production at the Tevatron has been observed to be anomalously large by both CDF and D0. It has been suggested that a model with a $W'$ coupling to $td$ and $ub$ might explain…
A first measurement of the top quark spin asymmetry, sensitive to the top quark polarisation, in $t$-channel single top quark production is presented. It is based on a sample of pp collisions at a centre-of-mass energy of 8 TeV…
The LHC is a promising machine to discover new physics in the top sector. There are several models that predict the existence of heavy colored resonances decaying to top quarks in the TeV energy range. The production of such resonances…
The DO collaboration reports on a search for the Standard Model top quark in pbar-p collisions at Sqrt(s)=1.8TeV at the Fermilab Tevatron, with an integrated luminosity of approximately 50pb-1. We have searched for t-tbar production in the…
The production of single top quarks allows to study the interplay of top quark physics and the electroweak sector of the standard model. Deviations from predictions can be a hint for physics beyond the standard model. The t-channel is the…
Deviations of the top electroweak couplings from their Standard Model values imply that certain amplitudes for the scattering of third generation fermions and longitudinally polarized vector bosons or Higgses diverge quadratically with…