Positive helicity Einstein-Yang-Mills amplitudes from the Double Copy

Understand

All positive helicity four-point gluon-graviton amplitudes in Einstein-Yang-Mills theory coupled to a dilaton and axion field are computed at the leading one-loop order using colour-kinematics duality.

• In particular, all relevant contributions in the gravitational and gauge coupling are established.
• This extends a previous generalized unitarity based computation beyond the leading terms in the gravitational coupling $\kappa$.
• The resulting purely rational expressions take very compact forms.