$ZH$ production in gluon fusion: two-loop amplitudes with full top quark mass dependence

TL;DR

This paper computes two-loop helicity amplitudes with full top quark mass dependence for Higgs and Z boson production via gluon fusion, providing essential inputs for precise NLO QCD predictions.

Contribution

It presents the first numerical calculation of two-loop integrals with massive top quarks for this process, including interference effects with the Born amplitude.

Findings

Numerical results for two-loop amplitudes as functions of kinematic invariants.

Interference effects between two-loop and Born amplitudes quantified.

Enhanced precision in theoretical predictions for Higgs-Z production in gluon fusion.

Abstract

We present results for the two-loop helicity amplitudes entering the NLO QCD corrections to the production of a Higgs boson in association with a $Z$-boson in gluon fusion. The two-loop integrals, involving massive top quarks, are calculated numerically. Results for the interference of the finite part of the two-loop amplitudes with the Born amplitude are shown as a function of the two kinematic invariants on which the amplitudes depend.