Pseudoscalar pole terms in the hadronic light-by-light scattering contribution to muong−2

Abstract

The pseudoscalar pole contribution is the dominant source of the $\mathcal{O}({\ensuremath{\alpha}}^{3})$ hadronic light-by-light scattering effect in muon $g\ensuremath{-}2$. We have examined this contribution, taking account of the off-shell structure of the pseudoscalar-photon-photon anomaly vertex deduced from available experimental data. Our work leads to an improved estimate $\ensuremath{-}79.2 (15.4)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}11}$ for the total hadronic light-by-light scattering contribution to the muon $g\ensuremath{-}2$.