Relativistic corrections in (γ,N) knockout reactions -: art. no. 064615

We develop a fully relativistic distorted wave impulse approximation (DWIA) model for photonuclear reactions using the relativistic mean field theory for the bound state, and the Pauli reduction of the scattering state, which is calculated from a relativistic optical potential. Results for the C-12( gamma ,p) and O-16(gamma ,p) differential cross sections and photon asymmetries are displayed in a photon energy range, between 60 and 257 MeV, and compared with nonrelativistic DWIA calculations The effects of the spinor distortion and of the effective momentum approximation for the scattering state are discussed. The sensitivity of the model to different prescriptions for the one-body current operator is investigated. The off-shell ambiguities are large in (gamma ,p) calculations, and even larger in (gamma ,n) knockout.