Abstract
We present a new framework for the extraction of the strong coupling from hadronic decays through finite-energy sum rules. Our focus is on the small, but still significant nonperturbative effects that, in principle, affect both the central value and the systematic error. We employ a quantitative model in order to accommodate violations of quark-hadron duality, and enforce a consistent treatment of the higher-dimensional contributions of the operator product expansion to our sum rules. Using 1998 OPAL data for the nonstrange isovector vector and axial-vector spectral functions, we find the values in fixed-order perturbation theory, and in contour-improved perturbation theory. For comparison, the original OPAL analysis of the same data led to the values (fixed order) and (contour improved).
- Received 13 October 2011
DOI:https://doi.org/10.1103/PhysRevD.84.113006
© 2011 American Physical Society