Transverse momentum-weighted Sivers asymmetry in semi-inclusive deep inelastic scattering at next-to-leading order

TL;DR

This paper calculates next-to-leading order QCD corrections to the transverse momentum-weighted Sivers asymmetry in semi-inclusive deep inelastic scattering, providing insights into the evolution of the Qiu-Sterman function and the hard coefficient at one-loop order.

Contribution

It presents the NLO perturbative QCD corrections to the Sivers asymmetry, including the derivation of the evolution kernel for the Qiu-Sterman function and the finite one-loop hard coefficient.

Findings

Identified the evolution kernel for the Qiu-Sterman function.

Evaluated the hard coefficient function at one-loop order.

Clarified the divergence structure in the NLO corrections.

Abstract

We study the next-to-leading order perturbative QCD corrections to the transverse momentum-weighted Sivers asymmetry in semi-inclusive hadron production in lepton-proton deep inelastic scattering. The corresponding differential cross section is evaluated as a convolution of a twist-three quark-gluon correlation function, often referred to as Qiu-Sterman function, the usual unpolarized fragmentation function, and a hard coefficient function. By studying the collinear divergence structure, we identify the evolution kernel for the Qiu-Sterman function. The hard coefficient function, which is finite and free of any divergence, is evaluated at one-loop order.