Isobars and the medium-energy (. gamma. ,p) reaction

摘要: Recently, precise experimental measurements have been obtained for the reaction /sup 16/O(..gamma..,p)/sup 15/N photon energies 50--350 MeV. For greater than 100 MeV, isobar photoproduction is expected to provide an important part of (..gamma..,p/sub 0/) reaction. We evaluate contribution (..gamma..,p) reaction, and we add this amplitude a term which corresponds direct knockout proton by photon. compare our results in detail with data from Glasgow Bates on 16/O. Our calculation uses coupling constants nuclear wave functions determined independent experiments, neglect isobar-nucleus interaction. Agreement quite reasonable, provides very large photoeffect 16/O, above about consider effects various corrections formalism, such as effect distortion outgoing nucleon force, center mass corrections, inclusion rho mesons addition pions at decay vertex. None these alters qualitative features its importance medium energies.