Complete helicity decomposition of the $gamma^*/Z^*tar{t}$ vertex including higher order QCD corrections and applications to $e^+e^-ightarrow t ar t$

摘要

The complete density matrix for all polarization configurations in theprocess B--> t tbar, where B is an off--shell Z or photon and t is the topquark, is calculated numerically including oneloop QCD corrections, i.e.virtual and real gluon contributions in O(alphas). The analysis is done in theframework of the helicity formalism. The results are particularly suited fortop quark production at the Linear Collider, but may be useful in othercircumstances as well. Relations to LEP and Tevatron physics are pointed out.