Effective potentials for heavy-ion scattering derived from channel coupling

Starting from coupled-channels equations, we use suitable approximations to derive effective interaction potentials for elastic heavy-ion scattering. These potentials are local, complex and l-dependent, and determined solely by the transition form factors and the zero-order elastic S-matrix elements. Although here we treat the couplings in first order only, our method can easily be extended to higher-order coupling by iteration. As examples we give explicit expressions for coupling to inelastic collective channels, by both Coulomb and nuclear excitation, and to transfer reaction channels. Aside from identifying the dynamical origin of various components of the total elastic interaction, we suggest that our potentials (or appropriate generalizations thereof) may be used in conventional optical model and DWBA codes as a simple substitute for coupled-channels calculations.