All-plus helicity off-shell gauge invariant multigluon amplitudes at one loop

TL;DR

This paper presents a gauge-invariant method for calculating one-loop multigluon scattering amplitudes with one off-shell gluon, applicable to any number of positive helicity gluons, within the quasi-multi Regge kinematics.

Contribution

It introduces a novel embedding technique that ensures gauge invariance and correct on-shell limits for off-shell gluon amplitudes at one loop.

Findings

The method produces fully gauge-invariant amplitudes.

Results are valid for any number of positive helicity gluons.

The approach correctly reproduces on-shell limits.

Abstract

We calculate one loop scattering amplitudes for arbitrary number of positive helicity on-shell gluons and one off-shell gluon treated within the quasi-multi Regge kinematics. The result is fully gauge invariant and possesses the correct on-shell limit. Our method is based on embedding the off-shell process, together with contributions needed to retain gauge invariance, in a bigger fully on-shell process with auxiliary quark or gluon line.