Abstract

In contrast to the extensively studied hydrogen atom, the quantum electrodynamic Lamb shift in helium also contains a two electron contribution. Accurate calculations show that the two electron shift contributes −0.1404 cm⁻¹ to a total Lamb shift of +1.3745 cm^{−1 1}in the ground state, which is one order of magnitude larger than in excited states of helium. The ground state Lamb shift was first measured by Herzberg in 1958² with an accuracy of 0.15 cm⁻¹.

© 1994 IEEE