A NOTE ON THE IMPLICATIONS OF CAUSALITY FOR L-DEPENDENT POTENTIALS

We have examined the l-dependence of the real part of the O-16 + O-16 potential which is required by causality as a result of surface transp arency being represented by a partial wave cutoff in the imaginary pot ential, with energy-dependent parameters. The effect is strong, sugges ting that the term arising from the dispersion correction needs to be included and that it may lead to an improvement in fitting scattering data for heavy-ion systems. This work also suggests that caution shoul d be taken in relating phenomenological l-dependence of the real part to, for example, RGM effects.