HIGHER-ORDER NUCLEAR-POLARIZABILITY CORRECTIONS IN ATOMIC-HYDROGEN

Nuclear-polarizability corrections that go beyond unretarded-dipole ap proximation are calculated analytically for hydrogenic (atomic) S stat es. These retardation corrections are evaluated numerically for deuter ium and contribute -0.68 kHz, for a total polarization correction of 1 8.58(7) kHz. Our results are in agreement with one previous numerical calculation, and the retardation corrections completely account for th e difference between two previous calculations. The uncertainty in the deuterium polarizability correction is substantially reduced. At the level of 0.01 kHz for deuterium, only three primary nuclear observable s contribute: the electric polarizability alpha(E), the paramagnetic s usceptibility beta(M), and the third Zemach moment [r(3)]((2)). Cartes ian multipole decomposition of the virtual Compton amplitude and its c oncomitant gauge sum rules are used in the analysis.