Analytic all-plus-helicity gluon amplitudes in QCD

TL;DR

This paper computes the first two-loop six- and seven-gluon amplitudes in QCD beyond five points using advanced unitarity and recursion methods, providing compact analytic results for all-plus helicity configurations.

Contribution

It introduces new computational techniques for two-loop amplitudes and presents the first such results for six- and seven-gluon processes in QCD.

Findings

First two-loop six-gluon amplitude in QCD

First two-loop seven-gluon amplitude in QCD

Amplitudes expressed in compact analytic forms

Abstract

We detail the calculation of two-loop all-plus helicity amplitudes for pure Yang-Mills theory. The four dimensional unitarity methods and augmented recursion techniques we have developed, together with a knowledge of the singular structure of the amplitudes allow us to compute these in compact analytic forms. Specifically we present the computation and analytic results for the six- and seven-gluon leading colour two-loop amplitudes these being the first QCD two-loop amplitudes beyond five-points.