Polarized structure functions of nucleons and nuclei

TL;DR

This paper models the quark distributions and structure functions in nucleons and nuclei, incorporating medium modifications to explain unpolarized and polarized deep inelastic scattering data, and extends the model to fragmentation functions.

Contribution

It introduces a model accounting for scalar and vector mean fields in nuclei to explain both unpolarized and polarized EMC effects, including predictions for polarized measurements.

Findings

Successfully reproduces experimental unpolarized EMC data

Provides predictions for polarized EMC effect in specific nuclei

Extends the model to describe fragmentation functions

Abstract

We determine the quark distributions and structure functions for both unpolarized and polarized DIS of leptons on nucleons and nuclei. The scalar and vector mean fields in the nucleus modify the motion of the quarks inside the nucleons. By taking into account this medium modification, we are able to reproduce the experimental data on the unpolarized EMC effect, and to make predictions for the polarized EMC effect. We discuss examples of nuclei where the polarized EMC effect could be measured. We finally present an extension of our model to describe fragmentation functions.