Recoil proton polarization: A new discriminative observable for deeply virtual Compton scattering

Generalized parton distributions describe the correlations between the longitudinal momentum and the transverse position of quarks and gluons in a nucleon. They can be constrained by measuring photon leptoproduction observables, arising from the interference between Bethe-Heitler and deeply virtual Compton scattering (DVCS) processes. At leading-twist/leading-order, the amplitude of the latter is parametrized by complex integrals of the GPDs {H; E; longitudinally polarized target constrains H and similar to H, E is poorly known as it requires data collected with a transversely polarized target, which is very challenging to implement in fixed-target experiments. The only alternative considered so far has been DVCS on a neutron with a deuterium target, while assuming isospin symmetry and absence of final-state interactions. Today, we introduce the polarization of the recoil proton as a new DVCS observable, highly sensitive to E, which appears feasible for an experimental study at a high-luminosity facility such as Jefferson Lab. similar to H; E similar to}. As data collected on an unpolarized or

Automated summary

Generalized parton distributions describe the correlations between momentum and position of quarks and gluons in a nucleon. They can be constrained by measuring photon leptoproduction observables. The polarization of the recoil proton is introduced as a new DVCS observable that is highly sensitive to E, and it can be studied experimentally at a high-luminosity facility like Jefferson Lab.