Hadron tomography through Wigner distributions

TL;DR

This paper explores the Wigner functions of the nucleon to provide a comprehensive multidimensional image of quark distributions in phase space, linking GPDs and TMDs, and estimating quark orbital angular momentum.

Contribution

It presents the first detailed calculation of nucleon Wigner distributions in a light-cone constituent quark model, connecting phase space distributions with angular momentum.

Findings

Distribution of unpolarized quarks in a longitudinally polarized nucleon is obtained.

Quark orbital angular momentum is estimated from the Wigner distribution.

Comparison with GPD and TMD based definitions shows consistency.

Abstract

We study the Wigner functions of the nucleon which provide multidimensional images of the quark distributions in phase space and combine in a single picture all the information contained in the generalized parton distributions (GPDs) and the transverse-momentum dependent parton distributions (TMDs). In particular, we present results for the distribution of unpolarized quarks in a longitudinally polarized nucleon obtained in a light-cone constituent quark model. Treating the Wigner distribution as it was a classical distribution, we obtain the quark orbital angular momentum and compare it with alternative definitions given in terms of the GPDs and the TMDs.