8TH-ORDER QED CONTRIBUTION TO THE ANOMALOUS MAGNETIC-MOMENT OF THE MUON

We report a calculation of the eighth-order QED contribution to the muon anomalous magnetic moment a(8) coming from 469 Feynman diagrams, all of which contain electron loops of vacuum-polarization type and/or light-by-light scattering type. Our result is 126.92(41)()4. The error represents the estimated accuracy (90% confidence limit) of the required numerical integration. We also report an estimate of the tenth-order contribution to a. Combining these with the lower-order results and the latest theoretical value for the electron anomaly ae, we find that the QED contribution to the muon anomaly is given by aQED=1165846947(46)(28)×10-12, where the first error is an estimate of theoretical uncertainty and the second reflects the measurement uncertainty in . Including the hadronic and electroweak contributions, the best theoretical prediction for a available at present is atheory=116591920(191)×10-11, where the error comes predominantly from the hadronic contribution. © 1990 The American Physical Society.