Reevaluation of the hadronic vacuum polarisation contributions to the Standard Model predictions of the muon $g-2$ and ${\alpha (m_Z^2)}$ using newest hadronic cross-section data
Résumé
We reevaluate the hadronic vacuum polarisation contributions to the muon magnetic anomaly and to the running of the electromagnetic coupling constant at the Z-boson mass. We include newest $e^+e^- \rightarrow \mathrm{hadrons}$ cross-section data (among others) from the BABAR and VEPP-2000 experiments. For the muon $(g-2)/2$ we find for the lowest-order hadronic contribution $(693.1 \pm 3.4)\times 10^{-10}$ , improving the precision of our previous evaluation by 21%. The full Standard Model prediction differs by $3.5\,\sigma $ from the experimental value. The five-quark hadronic contribution to $\alpha (m_Z^2)$ is evaluated to be $(276.0\pm 0.9)\times 10^{-4}$ .