Related papers: Gluon Polarization in $e^+e^-\to t\bar tG$
Top quark production in the process $e^+e^- \rightarrow t\bar{t}$ at a future linear electron positron collider with polarised beams is a powerful tool to determine indirectly the scale of new physics. The presented study, based on a…
We argue that multi-particle production in high energy hadron and nuclear collisions can be considered as proceeding through the production of gluons in the background classical field. In this approach we derive the gluon spectrum…
We discuss the polarised fragmentation functions of quarks and gluons in Perturbative Quantum Chromodynamics. The Altarelli-Parisi evolution equations governing these fragmentation functions are presented. We find that the first moment of…
At future $\gamma \gamma$ colliders copious production of $t \bar{t}$ pairs is possible. This would allow a detailed investigation of the interactions involving the top quark. We propose some orrelations which are sensitive to $t \bar{t}$…
The complete details of our calculation of the NLO QCD corrections to heavy flavor photo- and hadroproduction with longitudinally polarized initial states are presented. The main motivation for investigating these processes is the…
Gluon fragmentation to heavy $J^{PC}=2^{-+}$ quarkonia is studied herein. We compute these D-wave states' polarized fragmentation functions and find that they are enhanced by large numerical prefactors. The prospects for detecting the…
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…
Using a novel analysis technique, the gluon polarisation in the nucleon is re-evaluated using the longitudinal double-spin asymmetry measured in the cross section of semi-inclusive single-hadron muoproduction with photon virtuality…
We study soft-gluon corrections for the associated production of a single top quark and a $Z$ boson ($tqZ$ production) at hadron colliders. We find that the radiative corrections are dominated by soft-gluon emission. We calculate the…
We present a computation of QCD next-to-leading order corrections to the top production and decay process at linear colliders. The top quarks are allowed to be off-shell and the production and decay subprocesses are treated together, thus…
We combine heavy-quark renormalization group arguments with our understanding of the nucleon's wavefunction to deduce a bound on the gluon polarization Delta g in the proton. The bound is consistent with the values extracted from spin…
Longitudinal polarizations of different kinds of hyperons produced in e+e- annihilation at LEP I and LEP II energies in different event samples are calculated using two different pictures for the spin structure of hyperon: that drawn from…
At hadron colliders, the leading production mechanism for a pair of photons is from quark-anti-quark annihilation at the tree level. However, due to large gluon-gluon luminosity, the loop-induced process $gg\to \gamma \gamma$ provides a…
For top-quarks produced via the subprocess $q\bar q\to t\bar t$, the longitudinal t-quark polarization ($P_{\parallel}$) vanishes in QCD. $P_{\parallel}$ can be measured by the angular distribution of the lepton in $t$-quark semileptonic…
The energy spectra of the lepton(s) in eebar --> ttbar --> l^{+-}X/ l^+l^- X' at next linear colliders (NLC) are analyzed a model-independent way for arbitrary longitudinal beam polarizations as a general test of possible anomalous…
The complete density matrix for all polarization configurations in the process B--> t tbar, where B is an off--shell Z or photon and t is the top quark, is calculated numerically including oneloop QCD corrections, i.e. virtual and real…
We show how anisotropy in momentum of the gluon distribution in ultrarelativistic heavy ion collisions gives rise to polarization of direct photons produced via gluon-quark Compton scattering, as well as by quark-antiquark annihilation into…
We report on the resummation of soft-gluon emissions for squark-antisquark production at next-to-next-to-leading-logarithmic (NNLL) accuracy. We will put particular emphasis on the one loop hard matching coefficients required to perform the…
Beam polarization at e^+e^- linear colliders will be a powerful tool for high precision analyses. In this paper we summarize the polarization-related results for Higgs and electroweak physics, QCD, Supersymmetry and alternative theories…
Numerical studies of the bulk properties of the quark-gluon plasma reveal a pronounced drop in pressure $p$ compared to energy density $\e$ as the deconfining temperature is approached from above. We show by general thermodynamic reasoning…