Statistical parton distributions, TMD, positivity and all that

TL;DR

This paper reviews the quantum statistical approach to parton distributions, compares NLO QCD predictions with experimental data, explores transverse momentum dependence, and introduces new positivity constraints impacting spin observables.

Contribution

It introduces a quantum statistical model for parton distributions, extends it to include transverse momentum dependence, and derives new positivity constraints for spin observables.

Findings

Successful comparison of NLO QCD predictions with experimental data

Extension of parton distributions to include transverse momentum

New positivity constraints for spin observables

Abstract

We briefly recall the main physical features of the parton distributions in the quantum statistical picture of the nucleon. Some predictions from a next-to-leading order QCD analysis are successfully compared to recent unpolarized and polarized experimental results. We will discuss the extension to the transverse momentum dependence of the parton distributions and its relevance for semiinclusive deep inelastic scattering. Finally, we will present some new positivity constraints for spin observables and their implications for parton distributions.