Azimuthal asymmetries in semi-inclusive DIS with polarized beam and/or target and their nuclear dependences

TL;DR

This paper calculates azimuthal asymmetries in semi-inclusive deep inelastic scattering with polarized beams and targets, incorporating twist-3 effects, and explores their nuclear dependence, revealing suppression similar to unpolarized cases.

Contribution

It provides a detailed derivation of azimuthal asymmetries at twist-3 level and analyzes their nuclear dependence using collinear expansion and QCD equations of motion.

Findings

Azimuthal asymmetries are expressed in terms of twist-3 parton correlation functions.

Nuclear dependence shows similar suppression factors as unpolarized reactions.

Derived relationships between different twist-3 functions using QCD equations of motion.

Abstract

Using the formalism obtained from collinear expansion, we calculate the differential cross section and azimuthal asymmetries in semi-inclusive deeply inelastic lepton-nucleon (nucleus) scattering process $e^-+N (A) \to e^-+q+X$ with both polarized beam and polarized target up to twist-3. We derive the azimuthal asymmetries in terms of twist-3 parton correlation functions. We simplify the results by using the QCD equation of motion that leads to a set of relationships between different twist-3 functions. We further study the nuclear dependence of azimuthal asymmetries and show that they have similar suppression factors as those in the unpolarized reactions.