Saved in:
Bibliographic Details
Main Authors: Wang, Guoxing, Yang, Li Lin
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2510.01774
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866915530719363072
author Wang, Guoxing
Yang, Li Lin
author_facet Wang, Guoxing
Yang, Li Lin
contents The associated production of a photon and a top-antitop quark pair ($t\bar{t}γ$) is important for measuring the top-quark charge and probing the top-photon interaction, and it requires improved theoretical predictions. We focus on the calculation of two-loop amplitudes for $t\bar{t}γ$ production at hadron colliders. The infrared singularities with full top-quark mass dependence are derived from universal anomalous dimensions combined with one-loop massive amplitudes expanded to higher orders in the dimensional regulator $ε$. The finite remainders are approximated in the high-energy boosted limit using the mass-factorization formula. To validate our approach, we compare approximate one-loop amplitudes up to $\mathcal{O}\left(ε^2\right)$, as well as the two-loop infrared poles, against our exact results. The results in this paper serve as an important step toward next-to-next-to-leading order predictions for $t\bar{t}γ$ production.
format Preprint
id arxiv_https___arxiv_org_abs_2510_01774
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Two-loop QCD amplitudes for $t\bar{t}γ$ production at hadron colliders
Wang, Guoxing
Yang, Li Lin
High Energy Physics - Phenomenology
The associated production of a photon and a top-antitop quark pair ($t\bar{t}γ$) is important for measuring the top-quark charge and probing the top-photon interaction, and it requires improved theoretical predictions. We focus on the calculation of two-loop amplitudes for $t\bar{t}γ$ production at hadron colliders. The infrared singularities with full top-quark mass dependence are derived from universal anomalous dimensions combined with one-loop massive amplitudes expanded to higher orders in the dimensional regulator $ε$. The finite remainders are approximated in the high-energy boosted limit using the mass-factorization formula. To validate our approach, we compare approximate one-loop amplitudes up to $\mathcal{O}\left(ε^2\right)$, as well as the two-loop infrared poles, against our exact results. The results in this paper serve as an important step toward next-to-next-to-leading order predictions for $t\bar{t}γ$ production.
title Two-loop QCD amplitudes for $t\bar{t}γ$ production at hadron colliders
topic High Energy Physics - Phenomenology
url https://arxiv.org/abs/2510.01774