Analysis of Proton Elastic Scattering Using Potentials Derived from Nucleon-Density Distributions and Two-Body Potentials

Proton elastic scattering data at 30.3 MeV are analyzed using the optical model recently developed by Greenlees, Pyle, and Tang. The present analysis differs from that given in the original paper in using a model-exact treatment of the spin-orbit and isospin terms of the potential. The quality of the fits obtained is insensitive to the detailed manner in which the potential is constructed and, in particular, to the choice of nucleon-nucleon force parameters. These parameters are therefore taken from an analysis of low-energy nucleon-nucleon scattering data, thus enabling the present analysis to give nuclear-neutron rms radii. The $n\ensuremath{-}p$ rms-radius difference is about zero for medium-weight elements and 0.1-0.2 F for heavy elements. Evidence is presented supporting the conclusion that the volume integral and the rms radius of the real central potential are the well-defined quantities which can be deduced from analyses of elastic proton scattering data.