Deeply virtual compton scattering at HERA and perspectives at CERN

TL;DR

This paper reviews recent HERA data on deeply virtual Compton scattering (DVCS) to explore the nucleon's three-dimensional structure and discusses future measurements at CERN's COMPASS experiment.

Contribution

It analyzes recent experimental data on DVCS from HERA and outlines future measurement prospects at CERN to enhance understanding of nucleon structure.

Findings

HERA data constrains GPD models

Beam Charge Asymmetry measurements provide new insights

Future CERN measurements aim to deepen 3D nucleon imaging

Abstract

Standard parton distribution functions contain neither information on the correlations between partons nor on their transverse motion, then a vital knowledge about the three dimensional structure of the nucleon is lost. Hard exclusive processes, in particular DVCS, are essential reactions to go beyond this standard picture. In the following, we examine the most recent data from HERA (at low $x_{Bj}<10^{-2}$) and their impact on GPD models. The most recent measurements of the Beam Charge Asymmetry by the H1 experiment is discussed. Perspectives are presented for further measurements of DVCS cross sections at CERN, within the COMPASS experiment.