Two-loop QCD amplitudes for $t\bar{t}H$ production from boosted limit

TL;DR

This paper calculates two-loop QCD amplitudes for $t\bar{t}H$ production in the boosted limit, enabling more precise predictions of Higgs production associated with top quarks at colliders.

Contribution

It introduces a novel calculation of two-loop amplitudes for $t\bar{t}H$ production using a new mass-factorization formula in the high-energy limit.

Findings

Validated approximate methods against exact calculations.

Provided predictions for finite parts of two-loop amplitudes.

Enabled NNLO differential cross section computations.

Abstract

The production of a Higgs boson in association with a top-antitop quark pair ($t\bar{t}H$) holds significant importance in directly probing the top-quark Yukawa coupling, which is related to various fundamental questions in high energy physics. This paper focuses on the calculation of two-loop amplitudes for $t\bar t H$ production at hadron colliders in the high-energy boosted limit. The calculation employs our recently developed mass-factorization formula. To validate the accuracy of our approximate methods, we compare our results for the one-loop amplitudes and the two-loop infrared poles with the exact calculations. We then provide predictions for the finite parts of the two-loop amplitudes. By combining the contributions from real emissions, our results can be utilized to compute the next-to-next-to-leading order differential cross sections for $t\bar t H$ production in the high-energy boosted limit.