The phenomenology of proton elastic scattering and evidence for angular-momentum-dependent optical-model potentials

Abstract

An earlier suggestion of the authors (1976) that the proton optical-model potential has terms, both real and imaginary, which depend explicitly on angular momentum is hereby supported by a systematic study of proton scattering from ¹⁶O and ⁴⁰Ca at a wide range of energies, as well as ⁵⁸Ni and ⁵⁶Fe. Not only are the fits to data improved (in some cases the improvement is very great), but the extracted parameters show certain striking regularities which were less apparent in l-independent fits. We also make some general remarks concerning the status of phenomenological fits and the interpretation of l dependence.