$\mathcal{O}(\alpha {\alpha }_s)$ corrections to the $\gamma t\bar{t}$ vertex at the top quark threshold

Abstract

We compute the last missing piece of the two-loop $\mathcal{O}(\alpha {\alpha }_s)$ corrections to $\gamma t\bar{t}$ vertex at the $t\bar{t}$ threshold due to the exchange of a $W$ boson and a gluon. This contribution constitutes a building block of the top quark threshold production cross section at electron positron colliders.

Comments: 22 pages, 8 figures