The 12C(e, e′p) and 12C(e, e′pp) reactions in the Δ-resonance region

Coincidence cross sections for the 12C(e, e′pp) and 12C(e, e′p) reactions have been measured in the Δ-resonance region. The 12C(e, e′pp) reaction has been measured at three different angular settings of the proton detectors to investigate the angular correlation between the emitted protons. The data, which have a low statistical accuracy, are compared with a calculation based on the direct-knockout mechanism, which includes one- and two-body currents. NN-correlations are accounted for via a correlation function, Δ-excitation via a two-body current and final-state interactions of the emitted protons via an optical potential. The 12C(e, e′p) data, taken at large proton-emission angles, cover the region of high missing-energy values (145-275 MeV). The data are compared to results of a calculation taking into account meson exchange, intermediate Δ-excitation and pion production. This comparison shows that there is ample evidence for processes leading to multi-nucleon knockout.