On next-to-eikonal corrections to threshold resummation for the Drell-Yan and DIS cross sections

TL;DR

This paper investigates next-to-eikonal corrections to threshold resummation in Drell-Yan and DIS processes, proposing a new ansatz, and provides evidence for the exponentiation of leading NE logarithms.

Contribution

It develops tools to study NE logarithms, constructs an ansatz including NE corrections, and confirms the exponentiation of leading NE logarithms.

Findings

Evidence for exponentiation of leading NE logarithms

Validation of DMS collinear evolution approach

Comparison with exact multi-loop results supports the ansatz

Abstract

We study corrections suppressed by one power of the soft gluon energy to the resummation of threshold logarithms for the Drell-Yan cross section and for Deep Inelastic structure functions. While no general factorization theorem is known for these next-to-eikonal (NE) corrections, it is conjectured that at least a subset will exponentiate, along with the logarithms arising at leading power. Here we develop some general tools to study NE logarithms, and we construct an ansatz for threshold resummation that includes various sources of NE corrections, implementing in this context the improved collinear evolution recently proposed by Dokshitzer, Marchesini and Salam (DMS). We compare our ansatz to existing exact results at two and three loops, finding evidence for the exponentiation of leading NE logarithms and confirming the predictivity of DMS evolution.