A strategy towards the extraction of the Sivers function with TMD evolution

TL;DR

This paper proposes a new strategy to incorporate Q^2 dependence in the extraction of the Sivers function using TMD evolution, demonstrating success with recent experimental data.

Contribution

It introduces a simple method to include TMD evolution effects in Sivers function extractions from experimental data.

Findings

Successful description of COMPASS data with TMD evolution

Evidence supporting the phenomenological validity of TMD evolution equations

Improved agreement with experimental results compared to previous approaches

Abstract

The QCD evolution of the unpolarized Transverse Momentum Dependent (TMD) distribution functions and of the Sivers functions have been discussed in recent papers. Following such results we reconsider previous extractions of the Sivers functions from semi-inclusive deep inelastic scattering data and propose a simple strategy which allows to take into account the Q^2 dependence of the TMDs in comparison with experimental findings. A clear evidence of the phenomenological success of the TMD evolution equations is given, mostly, by the newest COMPASS data off a transversely polarized proton target.