Medium energy elastic proton scattering is analyzed with a microscopically generated nonlocal nucleon nucleus optical model. A through discussion is presented on the transition from a nonlocal potential to phase equivalent local potentials. These local potentials reveal a strong repulsive $l$-dependent core which is beyond phenomenological potential models. This core leads to a damping of the diffraction pattern at medium angles and a backward rise of the cross section. These features have been observed experimentally. The formalism is applied to scattering from ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ and ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$ at low and medium energies and compared to experimental data.

NUCLEAR REACTIONS Microscopic optical potential; ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}(p, p)$, $E=40, 180, 200$ MeV; ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}(p, p)$, $E=160, 180$ MeV; comparison with experimental data.

• Received 16 February 1982

DOI:https://doi.org/10.1103/PhysRevC.27.2466