PT Journal
AU Boito, D
   Cata, O
   Golterman, M
   Jamin, M
   Maltman, K
   Osborne, J
   Peris, S
TI New determination of alpha(s) from hadronic tau decays
SO Physical Review D
JI Phys. Rev. D
PY 2011
BP 113006
EP 19pp
VL 84
IS 11
DI 10.1103/PhysRevD.84.113006
LA English
AB We present a new framework for the extraction of the strong coupling from hadronic tau 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 n(f) = 3 values alpha(s)(m(tau)(2)) = 0.307 +/- 0.019 in fixed-order perturbation theory, and 0.322 +/- 0.026 in contour-improved perturbation theory. For comparison, the original OPAL analysis of the same data led to the values 0.324 +/- 0.014 (fixed order) and 0.348 +/- 0.021 (contour improved).
ER