Related papers: Longitudinal top quark polarization
In this contribution I review the physics of top quarks at a future Linear Collider. Main emphasis is put on the process e+ e- to ttbar close to threshold. Different physical observables, their sensitivity to the basic parameters and their…
Top quark production in the process $e^+e^- \rightarrow t\bar{t}$ at a future linear electron positron collider with polarized beams is a powerful tool to determine the scale of new physics. Studies at the $\ttbar$ threshold will allow for…
The polarization dependent momentum distributions of top quarks and their decay products are calculated for $t\bar t$ production at future $e^+e^-$ colliders with polarized beams. The Green function formalism is applied to this reaction…
We discuss the polarization and spin correlations of top quarks produced above threshold at a future linear collider, including QCD radiative corrections.
Calculations of radiative corrections to the top quark width are reviewed. QCD effects are discussed for $t-\bar t$ systems produced in $e^+e^-$ annihilation near the energy threshold.}
The top quark pairs produced at a polarized muon collider are in a (nearly) pure spin configuration. This result holds for all center-of-mass energies, and is insensitive to the next-to-leading order QCD radiative corrections. The decay…
We summarise a recent study looking at top quark polarisation effects in charged Higgs boson production. Lab frame angular and energy observables relating to leptonic decays of top quarks are analysed, and corresponding asymmetry parameters…
Measuring top polarization is extremely important in understanding any new physics that couples to top quark. Here, we take up the task of extracting polarization of top quark coming from TeV-scale stop decay at the upgraded high luminosity…
The polarizations of the heavy quark ($q=t$ or $b$) in the process $e^+e^- \to q \bar q h$ have been calculated in the general two Higgs doublet model. The CP violating normal polarization of the top quark can reach 8%, and $2 \sim 3%$ for…
We present the full O(alpha_s) longitudinal spin-spin correlations for heavy-quark pair production at e+ e- high-energy colliders in closed analytical form. In such reactions, quark and antiquark have strongly correlated spins, and the…
The top quark cross section close to threshold in $e^+e^-$ annihilation is computed including the summation of logarithms of the velocity at next-to-next-to-leading-logarithmic order in QCD. The remaining theoretical uncertainty in the…
Angular distributions of a mu+ and a b-quark resulting from the decay of a top quark produced at the e+e- linear collider with an unpolarized and a 100% longitudinally polarized electron beam are presented. The results of the standard model…
The massive one-loop {\it QCD} corrections to the production cross sections of We present the massive one-loop {\it QCD} corrections to the production cross sections of polarized quarks in the annihilation process $e^+e^-\to q\bar{q}(g)$…
If the forward-backward (FB) asymmetry of top quark ($A_{\rm FB}$) observed at the Tevatron deviates from the SM prediction, there must be $P$-violating interactions in $q\bar{q} \rightarrow t\bar{t}$. This new interaction will necessarily…
We calculate the linear and circular polarization of gluons produced in conjunction with massive quarks in the annihilation process $e^+e^-\to q \bar q G$. The linear polarization is calculated in the hadron event plane as well as in the…
Top quarks may be produced in large numbers in association with new physics at the LHC. The polarization of these top quarks probes the chiral structure of the new physics. We discuss several kinematic distributions which are sensitive to…
We put forward a method to tune the polarisation state of decaying heavy particles (top quarks and $W/Z$ bosons) in a pre-existing Monte Carlo sample. With this technique, dubbed as `custom angle replacement', the decay angular…
We study the spin properties of top quarks produced in collisions of polarized photons in the threshold region. For a relatively heavy top quark the influence of non-perturbative effects is small and its polarization parameters can be…
We compute the supersymmetric QCD corrections to the polarization and the spin correlations of top quarks produced above threshold in e+e- collisions, taking into account arbitrary longitudinal polarization of the initial beams.
In most of the models beyond the Standard Model, the top quark is expected to be polarized when produced in the decay of some heavier particle, like the gluino or the stop. The polarization is constructed, in an experiment or in…