Are generalized and transverse momentum dependent parton distributions related ?

TL;DR

This paper reviews the current understanding of potential relations between generalized parton distributions and transverse momentum dependent distributions, highlighting that no model-independent relations have been confirmed.

Contribution

It clarifies the status of relations between GPDs and TMDs, emphasizing the lack of model-independent non-trivial connections.

Findings

Relations exist in spectator models

No model-independent relations have been established

Current knowledge is primarily model-dependent

Abstract

The present knowledge on non-trivial relations between generalized parton distributions on the one hand and transverse momentum dependent distributions on the other is reviewed. While various relations can be found in the framework of spectator models, so far no model-independent non-trivial relations have been established.