On next-to-leading power threshold corrections in Drell-Yan production at N$^3$LO

TL;DR

This paper calculates a set of next-to-leading power threshold corrections at N$^3$LO for Drell-Yan production, focusing on the $C_F^3$ color structure, using the method of regions to expand around the threshold.

Contribution

It provides the first calculation of certain NLP threshold terms at N$^3$LO for Drell-Yan, expanding the understanding of higher-order QCD corrections.

Findings

Calculated $C_F^3$ contributions at N$^3$LO for Drell-Yan.

Expanded threshold corrections including subleading power terms.

Results aid in developing formalism for NLP threshold effects.

Abstract

The cross-section for Drell-Yan production of a vector boson has been previously calculated at next-to-next-to-leading order, supplemented by enhanced logarithmic terms associated with the threshold region. In this paper, we calculate a large set of enhanced terms associated with the colour structure $C_F^3$ at N$^3$LO, for the double real emission contribution in the quark-antiquark channel, as an expansion around the threshold region up to and including the first subleading power. We perform our calculation using the method of regions, which systematically characterises all contributions according to whether the virtual gluon is (next-to) soft, collinear or hard in nature. Our results will prove useful for developing general formalisms for classifying next-to-leading power (NLP) threshold effects. They are also interesting in their own right, given that they constitute a previously unknown contribution to the Drell-Yan cross-section at ${\cal O}(\alpha_s^3)$.