Deeply Virtual Compton Scattering off the neutron

Understand

The present experiment exploits the interference between the Deeply Virtual Compton Scattering (DVCS) and the Bethe-Heitler processes to extract the imaginary part of DVCS amplitudes on the neutron and on the deuteron from the helicity-dependent D$({\vec e},e'\gamma)X$ cross section measured at $Q^2$=1.9 GeV$^2$ and $x_B$=0.36.

• We extract a linear combination of generalized parton distributions (GPDs) particularly sensitive to $E_q$, the least constrained GPD.
• A model dependent constraint on the contribution of the up and down quarks to the nucleon spin is deduced.