An off-shell I.R. regularization strategy in the analysis of collinear divergences

TL;DR

This paper introduces an off-shell regularization approach combined with sector decomposition and Mellin-Barnes transform to analyze collinear divergences in QCD processes, demonstrated on deep inelastic scattering.

Contribution

It proposes a novel off-shell regularization strategy for collinear divergences using sector decomposition and Mellin-Barnes transform in Feynman amplitude analysis.

Findings

Effective regularization of collinear divergences demonstrated in one-loop DIS corrections.

Method provides a systematic way to analyze singularities in massless QCD amplitudes.

Strategy can be extended to other processes with collinear singularities.

Abstract

We present a method for the analysis of singularities of Feynman amplitudes based on the Speer sector decomposition of the Schwinger parametric integrals combined with the Mellin-Barnes transform. The sector decomposition method is described in some details. We suggest the idea of applying the method to the analysis of collinear singularities in inclusive QCD cross sections in the mass-less limit regularizing the forward amplitudes by an off-shell choice of the initial particle momenta. It is shown how the suggested strategy works in the well known case of the one loop corrections to Deep Inelastic Scattering.