An effective two nucleon interaction is defined by an optimal fit to select on- and half-off-of-the-energy shell t and g matrices determined by solutions of the Lippmann-Schwinger and Brueckner-Bethe-Goldstone equations with the Paris two nucleon interaction as input. As such, it reproduces the interaction on which it is based better than other commonly used, density dependent effective interactions. This new (medium modified) effective interaction, when folded with appropriate density matrices, has been used to define proton${\mathrm{-}}^{12}$C and proton${\mathrm{-}}^{16}$O optical potentials. With them elastic scattering data are well fit and the medium effects identifiable.

• Received 4 August 1993

DOI:https://doi.org/10.1103/PhysRevC.49.1309