Full-folding-model description of elastic scattering at intermediate energies

Nucleon-nucleus optical potentials are calculated using full off-shell nucleon-nucleon free t matrices based on the Paris potential. Applications to proton scattering from ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$ at 200 and 300 MeV are presented. Significant differences are found between observables calculated using full-folding potentials and tρ approximations to them, demonstrating the importance of an accurate treatment of off-shell effects. The agreement between calculated and measured observables improves substantially using the full-folding model.