The muon $g$-2 and $\Delta \alpha$ connection
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72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Engineering topics
Keshavarzi, Alex
Publications and source records attributed to Keshavarzi, Alex.
The strong coupling from e + e - → hadrons
We present a brief summary of our recent determination of αs from e + e - → hadrons, in the region 3 ≤ s ≤ 4 GeV 2 , with s the square of the center-of-mass energy.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
The strong coupling from $e^+e^-\to$~hadrons
We use a new compilation of the hadronic R R -ratio from available data for the process e^+e^-\to e + e − → hadrons below the charm mass to determine the strong coupling \alpha_s α s , using finite-energy sum rules. Quoting our results at the \tau τ mass to facilitate comparison to the results obtained from similar analyses of hadronic \tau τ -decay data, we find \alpha_s(m_\tau^2)=0.298\pm 0.016\pm 0.006 α s ( m τ 2 ) = 0.298 ± 0.016 ± 0.006 in fixed-order perturbation theory, and \alpha_s(m_\tau^2)=0.304\pm 0.018\pm 0.006 α s ( m τ 2 ) = 0.304 ± 0.018 ± 0.006 in contour-improved perturbation theory, where the first error is statistical, and the second error combines various systematic effects. These values are in good agreement with a recent determination from the OPAL and ALEPH data for hadronic \tau τ decays. We briefly compare the R(s) R ( s ) -based analysis with the \tau τ -based analysis.
Boito, Diogo↗