Determination of the strong coupling from hadronic tau decays using renormalization group summed perturbation theory

Abstract

We determine the strong coupling constant α_s from the τhadroni width using a renormalization group summed (RGS) expansion of the QCD Adler function. The main theoretical uncertainty in the extraction of α_s is due to the manner in which renormalization group invariance is implemented, and the as yet uncalculated higher order terms in the QCD perturbative series. We show that new expansion exhibits good renormalization group improvement and the behaviour of the series is similar to that of the standard CIPT expansion. The value of the strong coupling in {\bar{\rm MS}} scheme obtained with the RGS expansion is α_s(M_τ^2)= 0.338 \pm 0.010. The convergence properties of the new expansion can be improved by Borel transformation and analytic continuation in the Borel plane. This is discussed elsewhere in these proceedings.

Contribution to the proceedings of the workshop "Determination of the Fundamental Parameters of QCD", Nanyang Technological University, Singapore, 18-22 March 2013, to be published in Mod. Phys. Lett. A, version 2 contains an extra footnote and a reference compared to version 1

References in corpus (7)

• Hadronic Z- and tau-Decays in Order alpha_s^4
• The Determination of alpha_s from Tau Decays Revisited
• ${\alpha }_s$ from $\tau$ decays: contour-improved versus fixed-order summation in a new QCD perturbation expansion
• Perturbative expansion of the QCD Adler function improved by renormalization-group summation and analytic continuation in the Borel plane
• Strong coupling from the tau hadronic width by non-power QCD perturbation theory
• The QCD Running Coupling and its Measurement
• Determination of alpha_s from tau decays

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• Optimal renormalization and the extraction of the strange quark mass from moments of the $\tau$-decay spectral function
• Strong coupling from the tau hadronic width by non-power QCD perturbation theory
• Renormalization-group improved Higgs to two gluons decay rate
• Hadronic tau decays and the strong coupling