Computing One-Loop Amplitudes From The Holomorphic Anomaly Of Unitarity Cuts

TL;DR

This paper introduces a systematic method for computing specific unitarity cuts of one-loop N=4 gluon amplitudes, enabling the calculation of complex seven-gluon amplitudes with various helicity configurations.

Contribution

It extends previous methods to systematically compute all next-to-MHV n-gluon one-loop amplitudes of any helicity, including the complete seven-gluon amplitude.

Findings

Successfully computed the seven-gluon one-loop amplitude A_{7;1} with specified helicities.

Demonstrated the applicability of the method to all next-to-MHV amplitudes.

Provided a new systematic approach for calculating unitarity cuts in gauge theory amplitudes.

Abstract

We propose a systematic way to carry out the method introduced in hep-th/0410077 for computing certain unitarity cuts of one-loop N=4 amplitudes of gluons. We observe that the class of cuts for which the method works involves all next-to-MHV n-gluon one-loop amplitudes of any helicity configurations. As an application of our systematic procedure, we obtain the complete seven-gluon one-loop leading-color amplitude A_{7;1}(1-,2-,3-,4+,5+,6+,7+).