Phenomenological and Theoretical Optical Potentials

The optical potential (OP) is a powerful instrument for calculations on a wide variety of nuclear reactions, in particular, for quasi-elastic lepton-nucleus scattering. Phenomenological OPs are successful in the description of data but may produce uncertainties and ambiguities in the interpretation of the results. Two recent theoretical OPs are presented: a global relativistic folding OP, that has been employed in relativistic models for quasi-elastic lepton-nucleus scattering, and a nonrelativistic OP derived from nucleon-nucleon chiral potentials at fourth order (N4LO), that has been applied to elastic proton-nucleus scattering.