C(γ12,p) reaction atEγ=60 MeV

The ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$(γ,p${)}^{11}$B reaction has been studied using tagged photons and a new type of detector system that allowed proton groups leading to ${}_{}{}^{11}{}_{}{}^{}\mathrm{B}$ excited states to be resolved for the first time. A comparison between the intensities of states excited in the (γ,p) and (e,e’p) reactions reveals large differences, in particular for the 6.8 MeV doublet of ${}_{}{}^{11}{}_{}{}^{}\mathrm{B}$. This may indicate the importance of two-nucleon effects for the (γ,p) reaction which contrasts the single nucleon virtual photon absorption observed for (e,e’p) reactions.