Relations between generalized and transverse momentum dependent parton distributions

TL;DR

This paper reviews the current understanding of the relations between generalized parton distributions and transverse momentum dependent distributions, highlighting model-dependent findings and the lack of model-independent relations.

Contribution

It extends spectator model calculations and discusses the potential for non-trivial relations between different types of parton distributions.

Findings

Spectator models show various relations between distributions.

No non-trivial model-independent relations have been established.

The review summarizes current knowledge and extensions in spectator models.

Abstract

Recent work suggests non-trivial relations between generalized parton distributions on the one hand and (naive time-reversal odd) transverse momentum dependent distributions on the other. Here we review the present knowledge on such type of relations. Moreover, as far as spectator model calculations are concerned, the existing results are considerably extended. While various relations between the two types of parton distributions can be found in the framework of spectator models, so far no non-trivial model-independent relations have been established.