Recent progress in hadronic tau decays

Abstract

The determination of alpha_s from hadronic tau decays is impeded by the fact that two choices for the renormalisation group resummation, namely fixed-order (FOPT) and contour-improved perturbation theory (CIPT), yield systematically differing results. On the basis of a model for higher-order terms in the perturbative series, which incorporates well-known structure from renormalons, it is found that FOPT smoothly approaches the Borel sum for the tau hadronic width, while CIPT is unable to account for the resummed series. An example for the behaviour of QCD spectral function moments, displaying a similar behaviour, is presented as well.

6 pages, 3 figures. Talk presented at 11th International Workshop on Tau Lepton Physics, Manchester, UK, 13-17 September 2010

References in corpus (8)

• Hadronic Z- and tau-Decays in Order alpha_s^4
• The 2009 World Average of ${\alpha }_s$
• alpha_s and the tau hadronic width: fixed-order, contour-improved and higher-order perturbation theory
• The Determination of alpha_s from Tau Decays Revisited
• Alpha_s(M_Z) from hadronic tau decays
• Unraveling duality violations in hadronic tau decays
• ${\alpha }_s$ from $\tau$ decays: contour-improved versus fixed-order summation in a new QCD perturbation expansion
• Possible duality violations in tau decay and their impact on the determination of alpha_s

Cited by in corpus (3)

• Determination of ${\alpha }_s(M_{\tau }^2)$ from Improved Fixed Order Perturbation Theory
• Hadronic currents for ${\tau }^{-}\to {\pi }^{-}{\pi }^0{\nu }_{\tau }$ and other decays of interest in TAUOLA
• A new determination of higher-order QCD corrections to hadronic $\tau$ decays