Quasi-Free Scattering and Nuclear Structure

Quasi-free processes in nuclei are reviewed both from a theoretical and an experimental point of view. The discussion is limited to nuclei with mass number≥4 and to incident energies larger than 100 MeV for quasi-free proton-proton and 300 MeV for electron-proton scattering. The reactions are discussed qualitatively, and their relevance for the investigation of nuclear shells, in particular of the strongly bound ones, is shown. The cross section for quasi-free scattering is then derived in the distorted wave impulse approximation, and some special cases are considered. Through a few examples the main features of the experimental results are presented and compared with calculated ones. Measurements on several $1p$, $2s-1d$, and $2p-1f$ shell nuclei are discussed.