Proton single-particle energy shifts due to Coulomb correlations

A theoretically consistent approach to the calculation of the Coulomb correlation corrections to the single-particle energies is presented. New contributions to the single-particle energies previously overlooked in the literature are now identified and taken into account. We show that the interplay between the Coulomb interaction and the strong interaction, which is enhanced in the nuclear surface, leads to an upward shift of the proton single-particle levels. This shift affects the position of the calculated proton drip line, a shift towards decreasing Z. We describe briefly a similar mechanism which is at work for neutron levels. The same mechanism is responsible for significant corrections to the mass difference of the mirror nuclei (Nolen–Schiffer anomaly) and to the effective proton mass.