Deeply virtual Compton scattering on the neutron with positron beam
Résumé
Measuring DVCS on a neutron target is a necessary step to deepen our understanding of the structure of the nucleon in terms of Generalized Parton Distributions (GPDs). The combination of DVCS observables on neutron and proton targets allows to perform a flavor decomposition of the Compton Form Factors (CFFs), which are related to integrals of GPDs. Moreover, neutron-DVCS plays a complementary role to DVCS on a transversely polarized proton target in the determination of the CFF of the GPD E, the least known and constrained GPD that enters Ji’s angular momentum sum rule. A measurement of the beam-charge asymmetry (BCA) in the $e^{\pm } d\rightarrow e^{\pm }n\gamma (p)$ reaction can significantly impact the experimental determination of the real CFFs of the E and, to a lesser extent, $\widetilde{H}$ CFFs.