Collinear matching for next-to-leading power transverse-momentum distributions

TL;DR

This paper derives the tree-level expansion for next-to-leading power TMDs, including target mass corrections, revealing that only a few TMDs match to twist-three collinear distributions, simplifying semi-inclusive deep inelastic scattering analysis.

Contribution

It provides the first derivation of the expansion for genuine NLP quark-gluon-quark TMDs with target mass corrections, clarifying their matching to collinear distributions.

Findings

Limited TMDs match to twist-three collinear distributions.

Simplification in analyzing semi-inclusive deep inelastic scattering.

Target mass corrections included in the derivation.

Abstract

Phenomenological studies of transverse momentum dependent (TMD) parton distributions rely on the expansion in small values of the transverse separation of fields, where TMD parton distributions match onto collinear parton distribution functions. In this work, we derive this expansion at tree-level for the genuine next-to-leading power quark-gluon-quark TMDs, taking into account all the target mass corrections. We find that only a limited number of TMD parton distributions exhibit matching to twist-three collinear distributions, leading to a significant simplification in the analysis of the structure functions of semi-inclusive deep inelastic scattering.