Speaker
Description
We present the C++ library ggxy, which can be used for the fast and flexible calculation of partonic and hadronic cross sections to gluon-initiated top-mediated processes such as $gg\to HH$. We have extended the functionality of ggxy with the implementation of the $gg\to ZH$ and $gg\to VV$ processes. While all other parts are exact, the two-loop amplitudes with internal top quarks have been computed using analytical approximations that are valid in two opposite phase-space regions and together cover the full phase space. The expressions are ideal for a fast and numerically stable evaluation, while retaining the full dependence on all input parameters. This allows for a fast and flexible calculation of the NLO QCD corrections to $gg\to ZH$ and $gg\to VV$ with full top-quark mass dependence.