Influence of nuclear size on QED corrections in hydrogenlike heavy ions

The influence of the nuclear size and shape on quantum electrodynamic corrections to electron binding energies in heavy hydrogenlike ions is evaluated. For the self-energy, numerical values for the energy shift that take into account the size of the nucleus are given for 1S(1/2)-, 2S(1/2)-, and 2P(1/2)-states in the Z range from 26 to 110. Simple parametrizations are derived for the dependence of the self-energy and the vacuum polarization on the nuclear radius, which allow corrections to be made for small deviations from the currently known nuclear radii. The influence of nuclear size on second-order quantum electrodynamic corrections is examined for the two-loop vacuum-polarization contributions. The contribution is found to be experimentally indistinguishable from other contributions to the energy shift which an of nonquantum electrodynamic origin. [S1050-2947(98)03407-6].