Theory of the knockout of nucleon-nucleon pairs from nuclei by fast electrons

The analytical properties of the continuum wave functions are used to investigate the knockout of nucleon-nucleon pairs with low relative momentum from nuclei by high-energy electrons. The energy dependences for such processes are determined. The probabilities for the knockout of pp and pn pairs in their various possible spin states are estimated. The breakup of the 4He nucleus into three or four particles is analyzed. The effect of the levels of the observed and unobserved subsystems on the cross section is investigated. It is shown that the cross section cannot be enhanced by the simultaneous action of the levels of both subsystems. It is found that under certain conditions the characteristic opening angles of the pn pairs resulting from the complete breakup of the 4He nucleus are independent of the position of the level in the pn pair