Two-loop self-energy correction in H-like ions - art. no. 062507

A part of the two-loop self-energy correction, the so-called P term, is eva luated numerically for the Is state to all orders in Za. Our calculation. c ombined with the previous investigation [S. Mallampalli and J. Sapirstein. Phys. Rev.A57, 1548 (1998)]. yields the total answer for the two-loop self- energy correction in H-like uranium and bismuth. As a result. the major unc ertainty is eliminated from the theoretical prediction for the Lamb shift i n these systems, The total value of the ground-state Lamb shift in H-like u ranium is found to be 463.95(50) eV.