Improved theory of helium fine structure.
Improved theoretical predictions for the fine-structure splitting of 2(3)PJ levels in helium are obtained by the calculation of contributions of order alpha5 Ry. New results for transition frequencies nu(01) = 29616943.01(17) kHz and nu(12) = 2291161.13(30) kHz disagree significantly with the experimental values, indicating an outstanding problem in bound state QED.
Pachucki
Krzysztof
K
Institute of Theoretical Physics, Warsaw University, Hoza 69, 00-681 Warsaw, Poland.