The He-4(e, e ' p) cross section at high missing energies

The He-4(e, e' p) reaction has been studied in a kinematic regime in which short-range correlations are expected to have a strong impact on the reaction strength. The measured cross sections exhibit a bump-shaped structure at missing energies corresponding to quasi-free knockout of two nucleons. The results of microscopic calculations, that account for meson-exchange currents, intermediate Delta -excitation and final-state interactions, reproduce the data satisfactorily. The calculations indicate that at small proton emission angles the cross section is dominated by knockout of a correlated nucleon pair.