On the Role of the Running Coupling Constant in a Quark Model Analysis of T-odd TMDs

TL;DR

This paper explores how the non-perturbative behavior of the QCD running coupling constant influences the matching of hadronic models to experimental data, providing insights into the coupling's freezing and evolution.

Contribution

It introduces a non-perturbative generalization of the QCD running coupling to improve model-data matching and analyze the coupling's freezing behavior.

Findings

Enhanced understanding of the coupling's freezing in non-perturbative regimes

Improved matching procedure between models and experimental data

Insights into the validity of perturbative treatments in hadronic models

Abstract

We revisit the standard procedure to match non-perturbative models to perturbative QCD, using experimental data. The strong coupling constant plays a central role in the QCD evolution of parton densities. We will extend this procedure with a non-perturbative generalization of the QCD running coupling and use this new development to understand why perturbative treatments are working reasonably well in the context of hadronic models. Vice versa, this new procedure broadens the ways of analyzing the freezing of the running coupling constant.