Renormalization-group approach to the Coulomb pseudopotential for C60

A numerical renormalization-group technique recently developed by one of us is used to analyze the Coulomb pseudopotential (*) in C60 for a variety of short-range bare potentials. We find a large reduction in * due to intraball screening alone, leading to an interesting nonmonotonic dependence of * on the bare interaction strength. We find that * is positive for physically reasonable bare parameters, but small enough to make the electron-phonon coupling a viable mechanism for superconductivity in alkali-doped fullerides. We end with some open problems.