SENSITIVITY OF NUCLEAN-NUCLEUS SCATTERING TO THE OFF-SHELL BEHAVIOR OF ON-SHELL EQUIVALENT NN POTENTIALS

The sensitivity of nucleon-nucleus elastic scattering to the off-shell behavior of realistic nucleon-nucleon interactions is investigated wh en on-shell equivalent nucleon-nucleon potentials are used. The study is based on applications of the full-folding optical model potential f or an explicit treatment of the off-shell behavior of the nucleon-nucl eon effective interaction. Applications were made at beam energies bet ween 40 and 500 MeV for proton scattering from Ca-40 and Pb-208. We us e the momentum-dependent Paris potential and its local on-shell equiva lent as obtained with the Gelfand-Levitan and Marchenko inversion form alism for the two nucleon Schrodinger equation. Full-folding calculati ons for nucleon-nucleus scattering show moderate fluctuations in the c orresponding observables. This sets narrow margins within which off-sh ell features of the nucleon-nucleon interaction can be resolved. Based on these results, inversion potentials were also constructed directly from phenomenological phase shifts (SM94). Their use in nucleon-nucle us scattering at intermediate energies provides an improved descriptio n of the data relative to those obtained from current realistic potent ial models.