Nuclear polarization in muonic 204206207208Pb in the random-phase approximation

Muonic-atom nuclear polarization (NP) energy shifts have been calculated for 208Pb using the renormalized random-phase approximation (RPA) to describe the nuclear excitations. The RPA spectra are in good agreement with a number of direct experimental measurements, giving confidence that the present NP results are more reliable tha those of previous calculations by other authors. The authors find generally smaller energy shifts than in earlier work, in disagreement with several empirical determinations of these effects. Through a more critical examination of the data, it is argued that those empirical determinations may be incorrect, and it is suggested that the difficulties in fitting the data may lie in the splittings rather than in the absolute values of the transition energies, as has been assumed previously. Using empirical properties of some low-lying states in the isotopes 204206207208Pb, the results are adjusted and extended to provide a nearly complete and successful description of all such effects in these isotopes. (Auth.)