Reexamination of the helium fine structure

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 m alpha(7) and m(2)/M alpha(6). The previous result for the m alpha(7) correction is improved by a more accurate calculation of relativistic corrections to the Bethe logarithm. The theoretical values of the 2 P-3(0)-2 P-3(1) and 2 P-3(1)-2 P-3(2) fine-structure intervals in helium are, correspondingly, nu(01)=29 616 946.2(1.6) kHz and nu(12)=2 291 177.3(1.6) kHz, with the uncertainties being due to higher-order effects. For the small interval nu(12), the theoretical value agrees with the experimental data, whereas for the large interval nu(01), a discrepancy of about three standard deviations is present.