Speaker
Description
Understanding the multi-dimensional partonic structure of the nucleon via the measurement of Generalized Parton Distribution (GPDs) is one of the central goals of the scientific program of Jefferson Lab. While the 12-GeV program progresses, various upgrade scenarios open up perspectives to expand the measurable observables for Deeply Virtual Compton Scattering (DVCS) and other exclusive reactions giving access to GPDs, as well as to reach unexplored kinematical regimes.
This talk will present the experimental program, proposed for JLab, to measure DVCS ($eN \to eN \gamma$) on both the proton and the neutron, with the CLAS12 spectrometer and polarized positron and electron beams of 10.6 GeV. The proposed measurement of Double Deeply Virtual Compton Scattering (DDVCS, $eN \to eN \ell^+\ell^-$) with the SOLID spectrometer will also be presented. These experimental configurations will provide a direct access to the real parts of combinations of Compton Form Factors (CFFs), which are, in turn, connected to GPDs. The combination of DVCS observables on neutron and proton targets is a necessary step to perform the flavor decomposition of the real parts of the $H$ and $E$ CFFs. DDVCS will provide the unique possibility to disentangle the $x$ (average momentum fraction carried by the initial-final quark) dependence of the CFFs. The perspectives for the physics of GPDs that would open up with a possible doubling of the CEBAF accelerator energy will be also presented.
