Lepton-Pair Production in Virtual Compton Scattering off the Proton
arXiv:nucl-th/9701042 · doi:10.1016/S0370-2693(97)00389-4
Abstract
We show that lepton-pair production in Virtual Compton Scattering offers, through interference with the well-known Bethe-Heitler process, a sensitive probe to learn the longitudinal response of resonances and the electromagnetic nucleon form factors. This interference can be measured directly in terms of an asymmetry. The role of off-shell effects in the N-N-$γ$ vertices is investigated as well. An additional N-N-$γ-γ$ contact term in the amplitude, included to ensure gauge invariance of the model, cancels a substantial part of the off-shell effects.
8 pages, LaTeX , 2 figures. To appear in Phys. Lett. B