Role of the Δ(1232) in the (γ,p) reaction

The magnetic Born and intermediate-Δ contributions to the (γ,p) reaction are calculated for ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ and ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ targets, within a framework which includes pion rescattering and proton distortions. The results are discussed in light of experimental data, which show no obvious resonant energy dependence for these nuclei. The calculations are also compared to several published theoretical approaches, which disagree with each other regarding the importance of the intermediate-Δ contribution to the (γ,p) reaction at intermediate energies.