N$^3$LO extraction of the Sivers function from SIDIS, Drell-Yan, and $W^\pm/Z$ data

TL;DR

This paper performs a comprehensive global analysis of various high-energy scattering data to extract the Sivers function at N$^3$LO accuracy, providing insights into spin-momentum correlations and testing fundamental QCD predictions.

Contribution

It introduces a N$^3$LO framework for extracting the Sivers function from multiple processes, including SIDIS and Drell-Yan, and determines the Qiu-Sterman function in a model-independent manner.

Findings

Successful extraction of the Sivers function for u, d, s, and sea-quarks.

Evidence supporting the predicted sign change of the Sivers function between SIDIS and Drell-Yan.

Quantitative determination of the Qiu-Sterman function from the Sivers function.

Abstract

We perform the global analysis of polarized Semi-Inclusive Deep Inelastic Scattering (SIDIS), pion-induced polarized Drell-Yan (DY), and $W^\pm/Z$ boson production data and extract the Sivers function for $u$, $d$, $s$ and for sea-quarks. We use the framework of transverse momentum dependent factorization at N$^3$LO accuracy. The Qiu-Sterman function is determined in a model-independent way from the extracted Sivers function. We also evaluate the significance of the predicted sign change of Sivers function in DY with respect to SIDIS.