Two-proton emission induced by electron scattering

The theoretical framework of the electron-induced reactions where two nucleons are emitted is developed, pointing out analogies and differences with respect to the case of single-nucleon knockout. The triple-coincidence cross section is written in terms of the structure functions, which represent the response of the nucleus to the various components of the electromagnetic interaction. The cross section of the (e, e′2p) reaction is calculated in an unfactorized form, by integrating over the coordinates of the two ejected protons. The role of realistic short-range correlations and of the distortion of the two outgoing particles is investigated in the case of a coplanar and symmetrical kinematics. In this situation, the choice of the optical potential is not crucial, even though distortion is important. On the contrary, the cross section is very sensitive to the choice of the correlation function.