g factor of lithiumlike silicon 28Si11+

Abstract

The g factor of lithiumlike 28 Si 11+ has been measured in a triple-Penning trap with a relative uncertainty of 1.1•10 −9 to be gexp = 2.000 889 889 9(21). The theoretical prediction for this value was calculated to be g th = 2.000 889 909(51) improving the accuracy to 2.5 • 10 −8 due to the first rigorous evaluation of the two-photon exchange correction. The measured value is in excellent agreement with the state-of-the-art theoretical prediction and yields the most stringent test of bound-state QED for the g factor of the 1s 2 2s state and the relativistic many-electron calculations in a magnetic field.