Two-loop leading colour QCD corrections to di-photon plus jet production in the quark-antiquark and quark-gluon channels

by Federico Buccioni (University of Oxford (Rudolf Peierls Centre for Theoretical Physics))




The production of a pair of isolated highly energetic photons in proton-proton collisions represents an important class of processes for the physics programme at the LHC and at future hadron colliders. Given the target accuracy, the theoretical description of the production of a pair of photons with large transverse momentum calls for the computation of higher-order corrections, and the next-to-next-to-leading (NNLO) QCD ones are at the current frontier.

At the technical level, this is rendered non-trivial by the presence of two-loop amplitudes for 2->3 scattering processes.
In this talk, I will present the leading-colour and light-fermionic planar two-loop corrections for the production of two photons and a jet in the quark-antiquark and quark-gluon channels. The main object of my talk will be the interference of the two-loop amplitudes with the corresponding tree level ones, summed over colours and polarisations. This calculation uses the latest advancements in the algorithms for integration-by-parts reduction and multivariate partial fraction decomposition to produce compact and easy-to-use results. We have implemented our results in a computer program which is publicly available, and it can be used in conjunction with a Monte Carlo integrator.