Ground-state correlations in C12 and the mechanism of the (e,e'p) reaction

The mechanism of the quasi-elastic (e,e'p) reaction was studied to use the results in the extraction of nuclear-structure information from (e,e'p) measurements on C12. Two aspects of the (e,e'p) reaction: the interaction between the incident electron and the bound proton (e-p coupling); and the interaction between the outgoing proton and the residual nucleus (final-state interaction) were studied. Experimental information on the e-p coupling was obtained by carrying out the same (e,e'p) measurement at two values of the incident electron energy. It was demonstrated that the channel coupling (CC) effects in (e,e'p) are different from the CC-effects in elastic proton scattering. Employing the knowledge acquired on the electron-proton interaction and the final-state interaction, the momentum distributions corresponding to the 3/2 (-) ground state, the 1/2 (-) state at 2.215 MeV, and the 3/2 (-) state at 5.020 MeV in B11 were analyzed. The extracted spectroscopic factors exhaust only 57 + or - 7 percent of the 1p-sum rule. The low spectroscopic factors might be due to strong NN-correlations causing a depletion of valence orbitals.