All rational one-loop Einstein-Yang-Mills amplitudes at four points

TL;DR

This paper computes all four-point one-loop Einstein-Yang-Mills amplitudes with specific helicity configurations, revealing compact rational expressions and discussing their relation to color-kinematics duality and collinear limits.

Contribution

It provides the first complete calculation of these mixed amplitudes at one-loop with maximal gauge coupling powers, highlighting their simplified forms.

Findings

Amplitudes are purely rational and compact.

Results support color-kinematics duality.

Connections to gluon collinear limits are discussed.

Abstract

All four-point mixed gluon-graviton amplitudes in pure Einstein-Yang-Mills theory with at most one state of negative helicity are computed at one-loop order and maximal powers of the gauge coupling using D-dimensional generalized unitarity. The resulting purely rational expressions take very compact forms. We comment on the color-kinematics duality picture and a relation to collinear limits of pure gluon amplitudes.