The semiclassical approach to the exclusive electron scattering

The semi-classical approach, successfully applied in the past to the inelastic, inclusive electron scattering off nuclei, is extended to the treatment of exclusive processes. The associated formalism goes beyond the plane wave impulse approximation, since it can account also for the final states interaction in the mean field approximation, respecting the Pauli principle. We then explore, in the frame of two admittedly crude approximations, the impact on the exclusive cross section of the distortion of the outgoing nucleon wave. In addition also the influence, on the same observable, of the shape of the potential binding the nucleons into the nucleus is investigated. In accord with the findings of fully quantum mechanical calculations, the exclusive scattering is found to be quite sensitive to the mean field final states interaction, unlike the inclusive one. Indeed we verify that the latter is not affected, as implied by unitarity, by the distortion of the outgoing nucleon wave except for the effect of relativity, which is modest in the range of momenta up to about 500 MeV/c. Furthermore, depending upon the correlations between the directions of the outgoing and of the initial nucleon, the exclusive cross-section turns out to be remarkably sensitive to the shape of the potential binding the nucleons. These correlations also critically affect the domain in the missing energy - missing momentum plane where the exclusive process occurs. Finally the issue of the validity of the semi-classical framework, in leading order of the &ħ expansion, in providing a description of the exclusive processes is shortly addressed.