Cross sections for the exclusive photon electroproduction on the proton and Generalized Parton Distributions

Understand

Unpolarized and beam-polarized four-fold cross sections $\frac{d^4 \sigma}{dQ^2 dx_B dt d\phi}$ for the $ep\to e^\prime p^\prime \gamma$ reaction were measured using the CLAS detector and the 5.75-GeV polarized electron beam of the Jefferson Lab accelerator, for 110 ($Q^2,x_B,t$) bins over the widest phase space ever explored in the valence-quark region.

• Several models of Generalized Parton Distributions (GPDs) describe the data well at most of our kinematics.
• This increases our confidence that we understand the GPD $H$, expected to be the dominant contributor to these observables.
• Through a leading-twist extraction of Compton Form Factors, these results reveal a tomographic image of the nucleon.