Revised α⁴ Term of Lepton g-2 from the Feynman Diagrams Containing an Internal Light-By-Light Scattering Subdiagram

The α⁴ contribution to the lepton g-2 from a gauge-invariant set of 18 Feynman diagrams containing a light-by-light scattering subdiagram internally has been reevaluated by a method independent of the previous approach. Comparison of two methods revealed a program error in the first version. Correcting this error, the contributions of these 18 diagrams become -0.990 72(10)(α/π)⁴ and -4.432 43(58)(α/π)⁴ for the electron and muon g-2, respectively. The correction is not large enough to affect the comparison between theory and experiment for the muon g-2, but it does alter the inferred value for the fine structure constant α^-1 by 6 ppb.