Generalised Unitarity for Dimensionally Regulated Amplitudes

TL;DR

This paper introduces a new set of Feynman rules and unitarity cut-conditions for calculating one-loop amplitudes using a d-dimensional integrand reduction, applicable to both analytic and numerical computations, especially in NLO QCD.

Contribution

It develops a novel formalism with four-dimensional representations for d-dimensional integrand reduction, enhancing the computation of one-loop amplitudes.

Findings

Applicable to analytic and numerical calculations.

Effective for NLO QCD corrections.

Simplifies one-loop amplitude computations.

Abstract

We present a novel set of Feynman rules and generalised unitarity cut-conditions for computing one-loop amplitudes via d-dimensional integrand reduction algorithm. Our algorithm is suited for analytic as well as numerical result, because all ingredients turn out to have a four-dimensional representation. We will apply this formalism to NLO QCD corrections.