Related papers: Top Quark Pair Production in the Threshold Region
We investigate the single top quark production with the exchange of unparticles through high energy photon-photon collision $\gamma \gamma\to t \bar c$. The effects of unparticles on the scattering cross sections for different polarization…
We investigate the prospects to observe effects of transverse polarization of top quarks in $pp,p\bar{p}\to t\bar{t}X$. QCD absorptive parts generate a polarization of top quarks and antiquarks transverse to the production plane in the…
The weak decay of a polarized top quark has a rich structure of angular correlations among its decay products. We describe some of the noteworthy features of such decays. We then examine the three modes of single top production, with an…
We summarize the quantitative results of our analysis [1] of top-pair photoproduction in semileptonic mode in $pe$ collisions at the LHeC and FCC-he. We define three photoproduction regions, based on the rapidity acceptance range of the…
Angular and energy distributions for leptons and bottom quarks in the process e^+e^- --> t t-bar --> l^{+-}/b(b-bar) ... have been calculated assuming the most general top-quark couplings. The double distributions depend both on…
The process of top quark pair production at the ILC with subsequent decays of one of the top quarks to a charged Higgs boson and b-quark is considered. The charged Higgs decays to tau leptons whose polarization is the opposite to those…
We calculate the spin density matrix of top quark pairs for the reaction $e^+e^-\to t\bar{t}X$ to order $\alpha_s$. As an application we show next-to-leading order results for a variety of spin observables for the $t\bar{t}$ system. These…
Searches for new physics in the top quark sector are of great theoretical interest, yet some powerful avenues for discovery remain unexplored. We characterize the expected statistical power of the LHC dataset to constrain the single…
An optimal-observable analysis of the lepton angular and energy distributions from top-quark pair production with semi-leptonic decays in e+e- collisions is used to predict the potential sensitivity of the FCC-ee to the couplings of the top…
We present a detailed investigation of the NLO polarization of the top quark in t t-bar production at a polarized linear e^+ e^- collider with longitudinally polarized beams. By appropiately tuning the polarization of the beams one can…
We discuss associated production of a Higgs boson with a pair of $t {\bar t}$ quarks at a future high energy $e^+e^-$ collider. The process $e^+e^-\to t {\bar t}h$ is particularly sensitive to the presence of new physics and we consider the…
We calculate the longitudinal contribution to the alignment polarization $\Pl$ of quarks produced in $e^+e^-$ annihilation. In the Standard Model, the longitudinal alignment polarization vanishes at the Born term level and thus receives its…
We consider the decay of a polarized top quark into a polarized W-boson plus a bottom quark, followed by the decay of the W-boson into a pair of leptons or quarks. The polar angle distribution of the top spin relative to the W-momentum and…
The ratio of the structure functions for deep inelastic scattering in top pair production at future electron-proton colliders is analyzed at a fixed $\sqrt{s}$ and $Q^2$ relative to the minimum value of $x$ given by $Q^2/s$ using collinear…
We determine the real parts of electroweak matching conditions relevant for top quark pair production close to threshold in e+e- annihilation at next-to-next-to-leading logarithmic (NNLL) order. Numerically the corrections are comparable to…
In the Littlest Higgs model with T-parity (LHT), top-partners (T_-) are produced in pairs at the Large Hadron Collider (LHC). Each top-partner decays into a top quark (t) and the lightest T-odd gauge partner A_H. We demonstrate…
Within the extended framework of the Two-Higgs-Doublet Model Type II (2HDM-II), enhanced by a vector-like quark (VLQ) doublet $TB$, we present a comprehensive analysis of the process $e^{-}\gamma \rightarrow b\nu_{e}\bar{T}$ at future…
The most recent studies in the top quark sector are reviewed with the focus on the rare production mechanisms and suppressed decays. The experimental results obtained with the ATLAS and CMS detectors in proton-proton collisions at the…
We study the inclusive production of bottom-flavored hadrons from semileptonic decays of polarized top quarks at next-to-leading order in QCD using fragmentation functions recently determined from a global fit to $e^+e^-$ data. We provide…
The latest results from the CDF and D0 collaborations on the top-quark pair-production cross section and limits on electroweak production are presented. Included are measurements of properties of the top quark such as charge, lifetime, and…