title: Double deeply virtual Compton scattering off the nucleon.
abstract: We study the double deeply virtual Compton scattering (DDVCS) process off the nucleon, through the scattering of a space-like virtual photon with large virtuality resulting in the production of a time-like virtual photon, decaying into an e(+)e(-) pair. This process is expressed in the Bjorken regime in terms of generalized parton distributions (GPDs), and it is shown that by varying the invariant mass of the lepton pair, one can directly extract the GPDs from the observables. We give predictions for the DDVCS cross section and beam helicity asymmetry and discuss its experimental feasibility.
authors.affiliation: Institut de Physique Nucléaire, F-91406 Orsay, France.
authors.forename: M
authors.initials: M
authors.lastname: Guidal
authors.forename: M
authors.initials: M
authors.lastname: Vanderhaeghen