Sivers effect in Drell-Yan processes

TL;DR

This paper estimates Sivers asymmetries in Drell-Yan processes using recent distributions, highlighting their potential to test fundamental QCD predictions about spin asymmetries across multiple experimental facilities.

Contribution

It provides the first estimates of Sivers asymmetries in Drell-Yan processes based on recent SIDIS data, emphasizing their significance for testing QCD predictions.

Findings

Most asymmetries are predicted to be large.

Potential for a clear test of the Sivers sign change.

Supports the QCD factorization scheme for single spin asymmetries.

Abstract

The Sivers distributions recently extracted from semi-inclusive deep inelastic scattering data [1] are used to compute estimates for Sivers asymmetries in Drell-Yan processes which are being planned at several facilities (RHIC, COMPASS, J-PARC, PAX, PANDA, NICA (JINR) and SPASCHARM (IHEP)). Most of these asymmetries turn out to be large and could allow a clear test of the predicted sign change of the Sivers distributions when active in SIDIS and Drell-Yan processes. This is regarded as a fundamental test of our understanding, within QCD and the factorization scheme, of single spin asymmetries.