Cachazo-Svrcek-Witten Rules for Tree-Level Gluonic Amplitudes Revisited

TL;DR

This paper offers a new proof of the CSW rules for calculating tree-level gluonic amplitudes, emphasizing the cancellation of spurious poles through novel sub-amplitude analysis.

Contribution

It introduces a new proof of the CSW rules and explicitly demonstrates the cancellation of spurious poles using specially-defined sub-amplitudes.

Findings

Explicit cancellation of spurious poles confirmed

Introduction of two-off-shell-line sub-amplitudes

Enhanced understanding of gluonic amplitude calculations

Abstract

We provide a new proof of Cachazo-Svrcek-Witten rules for tree-level gluonic amplitudes. As a key step, we explicitly show the cancellation of spurious poles originating from the maximally helicity violating vertices in these rules. To achieve this, we introduce specially-defined two-off-shell-line sub-amplitudes and study their residues at spurious poles.