The role of the surface energy in nuclear octupole excitations

Octupole excitations of atomic nuclei can be viewed as fluctuations around an equilibrium shape. Shape fluctuations cause a change in the nuclear surface, and it is reasonable to suggest that such fluctuations may probe the nuclear surface energy. We use a series of Skyrme interactions, which were fitted to provide a systematic range of surface energies, to explore the surface energy dependence of octupole excitations in 208 Pb. We find a strong positive linear correlation between the surface energy of a Skyrme interaction and its prediction of the first 3 − octupole excitation energy.