Next-to-leading order corrections for $gg \to ZH$ with top quark mass dependence

TL;DR

This paper calculates the complete next-to-leading order corrections for the $gg o ZH$ process, incorporating top quark mass effects, to improve theoretical predictions for collider experiments.

Contribution

It introduces a novel method using small mass expansion to accurately compute two-loop virtual amplitudes with top quark mass dependence.

Findings

Reliable numerical results across all kinematic regions.

Phenomenological predictions for total and differential cross sections at the LHC.

Reduction of theoretical uncertainties to percent-level.

Abstract

In this Letter, we present for the first time a calculation of the complete next-to-leading order corrections to the $gg \to ZH$ process. We use the method of small mass expansion to tackle the most challenging two-loop virtual amplitude, in which the top quark mass dependence is retained throughout the calculations. We show that our method provides reliable numeric results in all kinematic regions, and present phenomenological predictions for the total and differential cross sections at the Large Hadron Collider and its future upgrades. Our results are necessary ingredients towards reducing the theoretical uncertainties of the $pp \to ZH$ cross sections down to the percent-level, and provide important theoretical inputs for future precision experimental collider programs.