Production of two Z-bosons in gluon fusion in the heavy top quark approximation

TL;DR

This paper calculates QCD corrections to Z-boson pair production via gluon fusion, focusing on top quark loops in the heavy mass approximation, and compares these to Higgs decay contributions.

Contribution

It provides the first estimate of QCD corrections to gluon-induced ZZ production considering only top quark loops in the heavy mass limit.

Findings

QCD corrections significantly affect ZZ production rates

Comparison shows differences between continuum and Higgs-mediated processes

Results aid in precise modeling of ZZ production at colliders

Abstract

We compute QCD radiative corrections to the continuum production of a pair of Z-bosons in the annihilation of two gluons. We only consider the contribution of the top quark loops and we treat them assuming that $m_t$ is much larger than any other kinematic invariant in the problem. We estimate the QCD corrections to $pp \to ZZ$ using the first non-trivial term in the expansion in the inverse top quark mass and we compare them to QCD corrections of the signal process, $pp \to H \to ZZ$.