Point-by-point extraction of parton distribution functions from SIDIS single transverse-spin asymmetries

TL;DR

This paper demonstrates a method to extract specific parton distribution functions related to nucleon transverse spin directly from experimental data, providing detailed insights into the nucleon's internal structure.

Contribution

It introduces a point-by-point extraction technique for transverse spin-dependent parton distribution functions using SIDIS asymmetry data, including the first determination of valence and sea Sivers functions from COMPASS measurements.

Findings

Successful extraction of valence and sea Sivers functions

Method enables detailed mapping of transverse spin structure

Provides new insights into nucleon spin composition

Abstract

We show how some parton distribution functions related to the transverse spin of nucleons can be extracted point by point from combinations of proton and deuteron observables. In particular, we present a determination of the valence and sea Sivers functions from the single-spin asymmetries measured by COMPASS.