On the two-loop amplitude for $gg \to ZZ$ production with full top-mass dependence

Abstract

In this talk, we discuss top-quark contributions to $ZZ$ production through gluon fusion at two loops. We use syzygies and modular arithmetic to compute the reductions to master integrals. In order to numerically evaluate the amplitude, we express it in terms of finite integrals using a new method to construct integrable linear combinations of divergent integrands.