$A_N$ in inclusive lepton-proton collisions: TMD and twist-3 approaches

TL;DR

This paper calculates the left-right azimuthal asymmetry in inclusive lepton-proton collisions with a transversely polarized nucleon using TMD and twist-3 formalisms, aligning with recent experimental data.

Contribution

It provides a comparative analysis of TMD and twist-3 approaches for asymmetry calculations, fixing non-perturbative correlators from other processes.

Findings

Results agree in sign with HERMES and Jefferson Lab data.

Both formalisms yield consistent asymmetry signs.

Discussion of similarities and differences between approaches.

Abstract

We consider the inclusive production of hadrons in lepton-nucleon scattering. For a transversely polarized nucleon this reaction shows a left-right azimuthal asymmetry, which we compute this asymmetry in both TMD and in twist-3 collinear factorization formalisms. All non-perturbative parton correlators of the calculation are fixed through information from other hard processes. Our results for the left-right asymmetry agree in sign with recent data for charged pion production from the HERMES Collaboration and from Jefferson Lab. We discuss similarities and differences of two formalisms.