Speaker
Maarten Golterman
(San Francisco State University)
Description
We use a new compilation of the hadronic R-ratio from available data for the process e+e−→ hadrons below the charm mass to determine the strong coupling αs, using finite-energy sum rules. Quoting our results at the τ mass to facilitate comparison to the results obtained from similar analyses of hadronic τ-decay data, we find αs(m2τ)=0.298±0.016±0.006 in fixed-order perturbation theory, and αs(m2τ)=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 τ decays.
