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

The pseudoscalar pole contribution is the dominant source of the $\mathcal{O}\left({\alpha }^3\right)$ hadronic light-by-light scattering effect in muon $g-2$. 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 $-79.2\hspace{0.5em}\mathrm{}\left(15.4\right)\mathrm{}\times {10}^{-11}$ for the total hadronic light-by-light scattering contribution to the muon $g-2$.