Improved Determination of $\alpha (M_{\mathrm{Z}}^2$) and the Anomalous Magnetic Moment of the Muon

Michel Davier, Andreas Hoecker

We reevaluate the hadronic contribution to the running of the QED fine structure constant \aqed at $s=M_{\mathrm{Z}}^2$. We use data from \ee\ annihilation and $\tau$ decays at low energy…