A coordinate description of partonic processes

TL;DR

This paper reviews a coordinate-space perturbative approach to partonic processes, providing intuitive insights into distance scales, factorization, and infrared cancellations in scattering amplitudes and Wilson line products.

Contribution

It introduces a coordinate-space framework for analyzing partonic amplitudes, offering new perspectives on factorization and infrared behavior compared to traditional momentum-space methods.

Findings

Develops coordinate-space leading regions for fixed-angle scattering

Establishes approximations and factorizations analogous to momentum space

Discusses infrared singularity cancellation in inclusive cross sections

Abstract

We review a perturbative description of amplitudes in coordinate space, aiming at an intuitive perspective on the roles of "long" and "short" distances. We begin with coordinate-space leading regions for fixed-angle scattering amplitudes, and develop approximations and factorizations in analogy to similar procedures in momentum space. There are also applications to products of Wilson lines, including the familiar cusp amplitude. We briefly discuss cross sections from the coordinate viewpoint, and the mechanism by which infrared singularities cancel in inclusive cross sections.