QCD Corrections to Toponium Production at Hadron Colliders

TL;DR

The paper develops a full next-to-leading order QCD treatment of toponium (η_t) production at hadron colliders, including gg, gq, and qqbar partonic channels, and couples this with QCD corrections to the η_t decay into γγ. It combines a perturbative calculation of production cross sections with a bound-state description via a two-loop QCD potential to obtain the wave function at the origin, R(0), and derives the γγ branching ratio, alongside γZ, ZZ, HZ, and WW channels. The analysis shows substantial NLO enhancements to production (especially for gg) and highlights the sensitivity to scales, PDFs, and the bound-state input, concluding that discovery prospects in the γγ channel remain challenging under reasonable assumptions. The work underscores the importance of precise QCD and bound-state inputs in predicting heavy-quarkonium-like signals at high-energy colliders.

Abstract

Toponium production at future hadron colliders is investigated. Perturbative QCD corrections to the production cross section for gluon fusion are calculated as well as the contributions from gluon-quark and quark-antiquark collisions to the total cross section. The dependence on the renormalization and factorization scales and on the choice of the parton distribution functions is explored. QCD corrections to the branching ratio of $η_{t}$ into $γγ$ are included and the two-loop QCD potential is used to predict the wave function at the origin. The branching ratio of $η_{t}$ into $γZ$, $ZZ$, $HZ$ and $WW$ is compared with the $γγ$ channel.