Compatibility of α_s(M_τ) with α_s(M_Z)

1998/08/31 by T. G. Steele, Steele, T. G., V. Elias +1
Mathematics · Physics and Astronomy · #advanced mathematical theories #hep-ph

paper · pdf · doi:10.48550/arxiv.hep-ph/9808490

Latex2e, 12 pages, 4 figures

arxiv created 1998/08/31 · arxiv updated 2009/11/30

Abstract

The current phenomenological determinations of α_s(M_τ) and α_s(M_Z) are shown to be only marginally consistent with the QCD evolution of the strong coupling constant between M_Z and M_τ. This motivates a revised estimate of α_s(M_τ) since the perturbative series used to extract α_s(M_τ) from the τ hadronic width exhibits slow convergence. Padé summation techniques provide an estimate of these unknown higher-order effects, leading to the revised determination α_s(M_τ)=0.333± 0.030 . This value is 10% smaller than current estimates, improving the compatibility of phenomenological estimates for α_s(M_τ) and α_s(M_Z) with the QCD evolution of the strong coupling constant.

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