Reexamination of helium fine structure
arXiv:0905.3046 · doi:10.1103/PhysRevA.79.062516
Abstract
In order to explain discrepancies between theoretical predictions and experimental data for the helium fine structure, we check and recalculate all theoretical contributions up to orders mα^7 and m^2/Mα^6. The previous result for the mα^7 correction is improved by a much more accurate calculation of relativistic corrections to the Bethe logarithm. The theoretical values of the 2^3P_0-2^3P_1 and 2^3P_1-2^3P_2 fine structure intervals in helium are, correspondingly, ν_{01} = 29616946.2(1.6) kHz and ν_{12} = 2291177.3(1.6) kHz, with the uncertanties being due to higher-order effects. For the small interval ν_{12}, the theoretical value agrees with the experimental data, whereas for the large interval ν_{01}, a discrepancy of about 3 standard deviations is present.
19 pages