Deeply Virtual Compton Scattering off the neutron

Abstract

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$(\vec{e},e^{\prime }\gamma )X$ 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.

Published in Phys. Rev. Lett