Diogo Boito

Strong coupling from the revised ALEPH data for hadronic τ decays

We apply an analysis method previously developed for the extraction of the strong coupling from the OPAL data to the recently revised ALEPH data for non-strange hadronic

K π vector form factor, dispersive constraints and τ → ν τ K π decays

\tau

An Updated determination of

decays. Our analysis yields the values

\alpha_s

\alpha_s(m_\tau^2)=0.296\pm 0.010

from

using fixed-order perturbation theory, and

\tau

\alpha_s(m_\tau^2)=0.310\pm 0.014

decays

using contour-improved perturbation theory. Averaging these values with our previously obtained values from the OPAL data, we find

Duality violations in τ hadronic spectral moments

\alpha_s(m_\tau^2)=0.303\pm 0.009

Kπ vector form factor constrained by τ → Kπντ and Kl3 decays

, respectively,

A new determination of \alpha_s from hadronic \tau\ decays

\alpha_s(m_\tau^2)=0.319\pm 0.012