Generalized unitarity for N=4 super-amplitudes

TL;DR

This paper introduces a supersymmetric generalized unitarity method for calculating N=4 super-amplitudes, successfully deriving compact forms of NMHV amplitudes and confirming dual conformal invariance at one loop.

Contribution

It develops a manifestly supersymmetric approach to generalized unitarity, enabling explicit computation of super-amplitudes and verification of dual conformal symmetry in N=4 SYM.

Findings

Derived compact, dual superconformally covariant NMHV tree amplitudes.

Confirmed dual conformal invariance of the one-loop NMHV to MHV amplitude ratio.

Validated conjectures from previous work on super-amplitude structures.

Abstract

We develop a manifestly supersymmetric version of the generalized unitarity cut method for calculating scattering amplitudes in N=4 SYM theory. We illustrate the power of this method by computing the one-loop n-point NMHV super-amplitudes. The result confirms two conjectures which we made in arXiv:0807.1095 [hep-th]. Firstly, we derive the compact, manifestly dual superconformally covariant form of the NMHV tree amplitudes for arbitrary number and types of external particles. Secondly, we show that the ratio of the one-loop NMHV to the MHV amplitude is dual conformal invariant.