Single top quark production and decay in hadron collision at next-to-leading order.

摘要

The top quark is by far the heaviest known fermion and the only known fermion with a mass at the electroweak symmetry breaking scale. Thus, it is hoped that a detailed study of top quark coupling to other particles will be of great utility in determining if the Standard Model mechanism for electroweak symmetry-breaking is the correct one, or if new physics is responsible. If the top quark does play a special role in nature, one must discover this fact through careful study of its properties which requires more accurate theoretical prediction. In this work we present a calculation of the next-to-leading order QCD corrections, with one-scale phase space slicing method, to the s-channel and the t-channel single top quark production and decay process at hadron colliders. Using the helicity amplitude method, the angular correlation of the final state particles and the spin correlation of the top quark are preserved. We discuss the effects of different contributions on the inclusive cross section of the single top production as well as various kinematic distributions after imposing the relevant cuts to select the single top signal events. The physics of single top production at the Tevatron is carefully studied, with a particular eye towards various kinematical distributions of the final state particles which can help to disentangle the single top event from the copious QCD backgrounds. After reconstructing the single top event, its polarization is examined in different spin bases.