On the perturbative expansion of tau hadronic spectral function moments

Abstract

In the determination of alpha_s from tau decays several different moments of the hadronic spectral functions have been used. In a recent work, we performed an analysis of their perturbative behaviour under two different assumptions for the higher-order coefficients of the Adler function. We showed that the various moments can be divided in a small number of classes. We concluded that some of the moments commonly employed in alpha_s extractions should be avoided due to their bad perturbative behaviour. Furthermore, for the moments that have a good perturbative behaviour, and under reasonable assumptions for the higher-order behaviour of the Adler function, fixed-order perturbation theory (FOPT) provides the superior framework for the renormalization group improvement. Here we discuss an extension of this analysis where we consider the perturbative series for values of the hadronic invariant mass squared s_0 < m_τ^2. Our conclusions are not altered within a reasonable s_0 window.

arXiv comment8 pages, 4 figures. Proceedings of the Xth Quark Confinement and the Hadron Spectrum, 8-12 October 2012, Munich, Germany

References in corpus (10)

• Hadronic Z- and tau-Decays in Order alpha_s^4
• An updated determination of α_s from tau decays
• 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
• Perturbative expansion of tau hadronic spectral function moments and alpha_s extractions
• Possible duality violations in tau decay and their impact on the determination of alpha_s
• Determination of ${\alpha }_s(M_{\tau }^2)$ from Improved Fixed Order Perturbation Theory
• On the determination of alpha_s from hadronic tau decays with contour-improved, fixed order and renormalon-chain perturbation theory
• A note on renormalon models for the determination of alpha_s(M_tau)

Cited by in corpus (4)

• Expansions of $\tau$ hadronic spectral function moments in a nonpower QCD perturbation theory with tamed large order behavior
• Perturbative Expansions in QCD Improved by Conformal Mappings of the Borel Plane
• Determination of alpha_s from tau decays
• Perturbative expansion of tau hadronic spectral function moments