Can we measure Double DVCS at JLab and the EIC?

TL;DR

This paper assesses the feasibility of measuring Double Deeply Virtual Compton Scattering (DDVCS) at JLab and future Electron-Ion Colliders, highlighting its potential for detailed nucleon structure studies.

Contribution

It provides a detailed feasibility analysis of DDVCS measurements at JLab and EIC, including cross-section estimates and sensitivity to GPD models.

Findings

DDVCS measurements are feasible at JLab and EIC energies.

Results show high sensitivity of observables to GPD behavior.

Estimated event rates are promising for future experiments.

Abstract

Double deeply virtual Compton scattering (DDVCS) is a very precise tool for the nucleon tomography. Its measurement requires high luminosity electron beams and precise dedicated detectors, since its amplitude is quite small in the interesting kinematical domain where collinear QCD factorization allows the extraction of quark and gluon generalized parton distributions (GPDs). We analyze the prospects for its study in the JLab energy domain as well as in higher energy electron-ion colliders. Our results are very encouraging for various observables both with an unpolarized and polarized lepton beam. Using various realistic models for GPDs, we demonstrate that DDVCS measurements are indeed very sensitive to their behaviour. Implementing our lowest order cross-section formulae in the EpIC Monte Carlo generator, we estimate the expected number of interesting events.