Multiple scattering corrections to the optical potential

A development is given of the self-consistent corrections to the nucleon optical potential. These corrections are implied by and contained in the third-order cluster terms of Brueckner theory as it applies to nucleon-nucleus interactions. The analysis is restricted to nucleons at low bombarding energies where multiple scattering corrections to the nucleon motion are important. It is possible to identify these corrections as the coupling of the nucleon to certain collective nuclear motions. The latter are produced when the cluster sum-over-states is performed according to a given set of prescriptions.