Exploring the nucleon structure through GPDs and TDAs in hard exclusive processes

TL;DR

This paper reviews recent advances in understanding nucleon structure using GPDs and TDAs, highlighting experimental and theoretical developments in hard exclusive processes like Compton scattering.

Contribution

It introduces the extension of GPDs to three-quark operators and discusses the significance of TDAs in nucleon to meson transitions.

Findings

Emphasizes the importance of both DVCS and timelike Compton scattering.

Highlights the role of TDAs in backward meson electroproduction.

Provides insights into the properties and applications of TDAs.

Abstract

Generalized Parton Distributions (GPDs) offer a new way to access the quark and gluon nucleon structure. We review recent progress in this domain, emphasizing the need to supplement the experimental study of deeply virtual Compton scattering by its crossed version, timelike Compton scattering. We also describe the extension of the GPD concept to three quark operators and the relevance of their nucleon to meson matrix elements, namely the transition distribution amplitudes (TDAs) which factorize in backward meson electroproduction and related processes. We discuss the main properties of the TDAs. \