The Use of Dispersion Relations in Hard Exclusive Processes and the Partonic Interpretation of Deeply Virtual Compton Scattering

TL;DR

This paper discusses the application of dispersion relations to hard exclusive processes like deeply virtual Compton scattering, highlighting potential issues with the partonic interpretation and proposing improvements.

Contribution

It critically examines the assumptions behind the holographic approach to generalized parton distributions and suggests a refined treatment for better physical consistency.

Findings

Identifies pitfalls in directly equating hadronic states with partons

Proposes an improved method for interpreting GPDs in dispersion relations

Highlights the importance of careful assumptions in holographic mappings

Abstract

Recently dispersion relations have been applied to hard exclusive processes such as deeply virtual Compton scattering, and a holographic principle was proposed that maps out the generalized parton distributions entering the soft matrix elements for the processes from their values on a given kinematical ridge. We examine possible pitfalls associated with the implicit, direct identification in this approach of the physical hadronic states with colored partons, and suggest an improved treatment of this assumption.