Analytical expressions for the dispersive contributions to the nucleon-nucleus optical potential

Mahaux and co-workers @1‐5# have shown how the study of the nuclear mean field may benefit from the use of dispersion relations. These are mathematical expressions that link certain contributions to the real and imaginary components of the optical model potential ~OMP!. The constraint imposed by these dispersion relations helps in reducing ambiguities in the construction of phenomenological potentials from fits to the experimental data. We refer specifically to the so-called dispersive contribution DV, which adds dynamical content to the otherwise static ~and real! Hartree-Fock potential term VHF . Under favorable conditions of analyticity in the complex E plane, the real part DV can be constructed from the knowledge of the imaginary part W of the mean field on the real axis through the dispersion relation