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

Yuichiro Kiyo, Dirk Seidel, Matthias Steinhauser

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. T…