A partonic description of the transverse target single-spin asymmetry in inclusive DIS

TL;DR

This paper develops a partonic, collinear twist-3 framework to describe the transverse target single-spin asymmetry in inclusive deep-inelastic scattering, linking it to multipartonic correlations and providing a basis for experimental constraints.

Contribution

It introduces a comprehensive partonic description of the asymmetry, incorporating multi-photon exchanges and twist-3 contributions, advancing the theoretical understanding of single-spin asymmetries in QCD.

Findings

Derived a finite, well-behaved formula for the asymmetry

Expressed the asymmetry in terms of multipartonic correlation functions

Highlighted the potential for experimental constraints on quark-gluon and quark-photon correlations

Abstract

The single-spin asymmetry of unpolarized leptons scattering deep-inelastically off transversely polarized nucleons is studied in a partonic picture within a collinear twist-3 framework. Since this observable is generated by multi-photon exchanges between lepton and nucleon a partonic description of the asymmetry contains essential elements of a full next-to-leading order calculation for single-spin asymmetries in perturbative Quantum Chromodynamics. In particular it is shown how nontrivial cancellations between kinematical and dynamical twist-3 contributions lead to a well-behaved and finite formula. This final result can be expressed in terms of multipartonic quark-gluon and quark-photon correlation functions. Hence, a measurement of the transverse target single-spin asymmetry may provide new constraints on these multipartonic correlations.