Discrete-spectrum contribution to the Lamb-shift of the 2S and 2P hydrogenic states

Abstract

Abstract.A general formula due to Moses [Phys. Rev. A 8, 1710(1973] for exact electric and magnetic multipole transition matrix elements in nonrelativistic hydrogenic atoms is reduced by carrying out additional integrations. By using the obtained reduced formula unrenormalized (finite) and renormalized Lamb-shift contributions stemming from individual discrete states as well as from the whole discrete spectrum are calculated in the case of the states 2S and 2P.