Abstract
We calculate the one- and two-loop corrections of order and , respectively, to the Lamb shift in hydrogenlike systems using the formalism of nonrelativistic quantum electrodynamics. We obtain general results valid for all hydrogenic states with nonvanishing orbital angular momentum and for the normalized difference of states. These results involve the expectation value of local effective operators and relativistic corrections to Bethe logarithms. The one-loop correction is in agreement with previous calculations for the particular cases of , , and states. The two-loop correction in the order includes the pure two-loop self-energy and all diagrams with closed fermion loops. The obtained results allow one to obtain improved theoretical predictions for all excited hydrogenic states.
- Received 8 September 2005
DOI:https://doi.org/10.1103/PhysRevA.72.062102
©2005 American Physical Society