Revised value of the eighth-order electron g-2

TL;DR

This paper recalculates the eighth-order electron g-2 contribution using a new computational approach, correcting previous infrared subtraction errors, resulting in a revised value and a shift in the fine structure constant.

Contribution

It introduces a new FORTRAN code and identifies and corrects an infrared subtraction error in previous calculations of the eighth-order electron g-2.

Findings

Revised eighth-order g-2 contribution: -1.9144(35) (alpha/pi)^4

Shift in inverse fine structure constant: -6.41180(73) x 10^{-7}

Enhanced accuracy in theoretical electron g-2 calculations

Abstract

The contribution to the eighth-order anomalous magnetic moment (g-2) of the electron from a set of diagrams without closed lepton loops is recalculated using a new FORTRAN code generated by an automatic code generator. Comparing the contributions of individual diagrams of old and new calculations, we found an inconsistency in the old treatment of infrared subtraction terms in two diagrams. Correcting this error leads to the revised value -1.9144 (35) (alpha/pi)^4 for the eighth-order term. This theoretical change induces the shift of the inverse of the fine structure constant by -6.41180(73)x10^{-7}.