Related papers: Polarized Heavy Quarks
The distributions of the bottom quark in the process $e^+ e^- \to t \, \bar{t} \to b \, W^+ \, \bar{t}$ are considered at the $e^+ e^-$ energy corresponding to the first construction stage of the Compact Linear Collider. The cross sections…
In the presence of an electric dipole coupling of $t \bar t$ to a photon, and an analogous ``weak" dipole coupling to the $Z$, $CP$ violation in the process $e^+e^- \rightarrow t \bar t$ leads to the polarization of the top and anti-top.…
We analyze the $Wt\bar b$ production processes and especially the rate of longitudinal $W$ polarization sensitive to a possible top quark mass scale dependence and to the presence of strong final state $Wt$ interactions for example…
Polarization observables in top quark decays are sensitive probes of possible new physics contributions to the interactions of the heavy third generation quarks. Within an effective theory approach such new physics contributions can be…
We show that the $ZWW$ production process may give complementary informations about scale dependent heavy particle masses and possible final state interactions as compared to previously studied top quark production processes. We illustrate…
In the presence of an electric dipole coupling of t-tbar to a photon, and an analogous "weak" dipole coupling to the Z, CP violation in the process e+e- --> t tbar results in modified polarization of the top and anti-top. This polarization…
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…
The analytic expressions for the production cross sections of polarized bottom and top quarks in $e^+e^-$ annihilation are explicitly derived at the one-loop order of strong interactions. Chirality-violating mass effects will reduce the…
We analyze the pair-production of top quarks in polarized $e^+e^-$ scattering in the presence of electroweak dipole moments. For this, we consider two $CP$-odd observables which probe both the real and the imaginary parts of these moments.…
Top pair production is ideally suited to observe post-decay entanglement, thus providing a novel test of quantum mechanics. We provide top polarised decay amplitudes that can be used to compute semi-analytical predictions and, in…
Effects of four-Fermi-type new interactions are studied in top-quark pair production and their subsequent decays at future e^+e^- colliders. Secondary-lepton-energy distributions are calculated for arbitrary longitudinal beam polarizations.…
We investigate the degree of spin polarization of single top quarks in the $e\gamma$ collision via the process $e^{+} \gamma \to t \bar{b} \bar{\nu_{e}}$ with center of mass energies $\sqrt{s}$=0.5, 1 and 1.5 TeV of the parental linear…
We study pair production of scalar top quarks in polarized photon-photon collisions with the subsequent decay of the top squarks into b-quarks and charginos. We simulate this process by using PYTHIA6.4 for an electron beam energy 2E_beam…
Angular and energy distributions for leptons and bottom quarks in the process e+e- --> t tbar --> l/b ... have been calculated assuming the most general top-quark couplings. The double distributions depend both on modification of the…
The longitudinal polarization of hyperons in $e^+e^-$ annihilation at high energies depends on the longitudinal polarization of the quark produced at the $e^+e^-$ annihilation vertex whereas the spin alignment of vector mesons is…
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…
We investigate the possibilities of studying new physics in various processes of t-quark production using kinematical distributions of the secondary lepton coming from decay of t quarks. We show that the angular distributions of 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…
A solution to the Schrodinger equation for the nonrelativistic Green function which is used for describing the heavy quark-antiquark pair production near the threshold in $e^+e^-$ annihilation is presented. A quick comparison with existing…
Based on the result in our previous work, we calculate the polarization of quarks from parton scatterings in high energy heavy ion collisions. The result is compared with the STAR data at $\sqrt{s_{NN}}=200$ GeV.