Two-proton emission induced by real and virtual photons

The cross sections of the (e, e′2p) and (γ, 2p) reactions are calculated in an unfactorized form by integrating over the coordinates of the two ejected protons. Realistic short-range correlations and distorted wave functions for the two outgoing particles are included in the calculation. The nuclear current is the sum of a one- and a two-body part, corresponding to the process where a Δ-resonance is excited in the intermediate state. The (e, e′2p) cross section essentially depends on correlations, while the two-body current gives a minor contribution. In the (γ, 2p) cross section both effects are important. The asymmetry of the cross section produced by linearly polarized photons is extremely sensitive to the two-body current and could be exploited to investigate its contribution