Generalized parton correlation functions for a spin-0 hadron

TL;DR

This paper introduces generalized parton correlation functions for spin-0 hadrons, linking generalized parton distributions and transverse momentum dependent distributions, and classifies these beyond leading twist.

Contribution

It provides a model-independent framework for generalized parton correlation functions and offers the first complete classification beyond leading twist.

Findings

Revealed relations between GPDs and TMDs

Classified GPDs beyond leading twist

Enhanced understanding of hadron structure

Abstract

The fully unintegrated, off-diagonal quark-quark correlator for a spin-0 hadron is parameterized in terms of so-called generalized parton correlation functions. Such objects are of relevance for the phenomenology of certain hard exclusive reactions. In particular, they can be considered as {\it mother distributions} of generalized parton distributions on the one hand and transverse momentum dependent parton distributions on the other. Therefore, our study provides new, model-independent insights into the recently proposed nontrivial relations between generalized and transverse momentum dependent parton distributions. As a by-product we obtain the first complete classification of generalized parton distributions beyond leading twist.