Optical Model for Proton Scattering fromCa40

A six-parameter optical model for proton elastic scattering from ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$ has been developed in which the real part of the potential has been generated from a matter distribution that reproduces the single-particle binding energies and electron elastic-scattering cross sections. A Gaussian nucleon-nucleon force has been used and an optimum range of 4.5 ± 0.4 ${\mathrm{fm}}^2$ extracted. Improved fits are obtained with a density-dependent effective interaction.