Transverse phase space and its multipole decomposition

TL;DR

This paper explores the four-dimensional transverse phase space in relativistic systems, identifying angular correlations and developing a representation to unify experimental information into a coherent framework.

Contribution

It provides a comprehensive classification of angular correlations in transverse phase space and introduces a new representation method for this four-dimensional space.

Findings

Identified all leading-twist angular correlations in transverse phase space

Developed a new representation for four-dimensional transverse phase space

Unified various experimental data into a coherent physical picture

Abstract

Relativistic phase space distributions are very interesting objects as they allow one to gather the information extracted from various types of experiments into a single coherent picture. Focusing on the four-dimensional transverse phase space, we identified all the possible angular correlations providing at the same time a clear physical interpretation of all the leading-twist generalized and transverse-momentum dependent parton distributions. We also developed a convenient representation of this four-dimensional space.