Three-body approach to the single-scattering optical potential

Abstract

We investigate the single-scattering optical potential in the multiple scattering approaches of Watson and of Kerman, McManus, and Thaler. Since the kinematics of single scattering is three body in nature, we build a three-body model of this term. This approach can include the proper kinematics for the struck nucleon, the identity of the target nucleons, and the binding interaction of the struck nucleon. Integral equations of the Faddeev type are derived for both the Watson and Kerman-McManus-Thaler single-scattering optical potentials. Unitarity relations are investigated and we observe that these relations can be expanded in order to identify the intermediate states responsible for the absorptive parts. The transition amplitudes to the inelastic states implicit in the model are extracted and evaluated. This permits one to understand the physical meaning of the imaginary part in precise terms. The same procedure is applied to the closure and impulse approximations for the single-scattering term and their implicit inelastic states and reaction amplitudes are identified. These approximations are evaluated by analyzing the inelastic data. We conclude that the impulse approximation to the Watson single-scattering term should provide the best two-body approximation to a single-scattering optical potential. NUCLEAR REACTIONS Study optical potential in Watson and KMT multiple-scattering theory, three-body model introduced, Faddeev equations derived, unitarity studied; applied to intermediate energy nucleon-nucleus scattering. DOI:https://doi.org/10.1103/PhysRevC.16.1924 ©1977 American Physical Society