Speaker
Description
In this talk I will present NNLO QCD predictions for the production of a top-antitop quark pair in association with a W boson. While results for this process have previously been obtained employing dynamical approximations for the two-loop virtual correction, this computation is based on the first direct calculation of the two-loop QCD amplitude in the leading-colour approximation. I will discuss strategies to address the complexity of the computation of the amplitude, which involves complicated analytic structures, such as nested square roots, elliptic functions, and expressions with a high degree of algebraic complexity. We express the final result in terms of a set of special functions, which we evaluate numerically through differential equations, and rational coefficients, that we evaluate via finite field techniques. Finally, I will present results for the NNLO QCD total cross section, based on an interpolation grid for the two-loop finite remainder.