A SYSTEMATIC SURFACE CONTRIBUTION TO THE GROUND-STATE BINDING-ENERGIES

We show that if there is a weak (perturbative) interaction between the particles of a many-body system, its contribution to the ground-stale binding energies is significantly enhanced by the presence of the sur face. The naive first-order perturbation estimate of the contribution of such an interaction severely underestimates the actual magnitude of the binding energy corrections, arising from an enhanced surface pola rizability. We exemplify this mechanism by computing the contribution to the nuclear ground-state energy coming from the Coulomb interaction between nucleons.