One-nucleon knockout calculations have been performed for the reaction ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$(γ,p${)}^{11}$B at incident photon energies of 60, 80, and 100 MeV. Both two-step processes and high-momentum components in the single-nucleon wave function due to short-range correlations have been included. It is shown that direct knockout leading to the ${}_{}{}^{11}{}_{}{}^{}\mathrm{B}$ ground state followed by inelastic excitation of the 7/$2^{\mathrm{-}}$ state at 6.743 MeV in ${}_{}{}^{11}{}_{}{}^{}\mathrm{B}$ exceeds the direct excitation of this state by 1 to 2 orders of magnitude. For the ground-state transition the influence of high-momentum components becomes increasingly important going from ${\mathit{E}}_{\gamma }$=60 to 100 MeV. Constraining the parameters entering the calculation by recently measured quasielastic ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$(e,e’p${)}^{11}$B data a discrepancy is found between the calculations and the data, particularly at low photon energies, which is attributed to exchange currents and random-phase approximation correlations.

• Received 25 April 1990

DOI:https://doi.org/10.1103/PhysRevC.42.2597