Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: $\alpha_s$ from the updated ALEPH data for hadronic $\tau$ decays   We extract the strong coupling $\alpha_s(m_\tau^2)$ from the recently updated
ALEPH non-strange spectral functions obtained from hadronic $\tau$ decays. We
apply a self-consistent analysis method, first tested in the analysis of OPAL
data, to extract $\alpha_s(m_\tau^2)$ and non-perturbative contributions. The
analysis yields $\alpha_s^{\rm FO}(m_\tau^2)=0.296\pm0.010 $, using Fixed Order
Perturbation Theory (FOPT), and $\alpha^{\rm CI}_s(m_\tau^2)= 0.310\pm0.014$,
using Contour Improved Perturbation Theory (CIPT). The weighted average of
these results with those previously obtained from OPAL data give $\alpha_s^{\rm
FO}(m_\tau^2)=0.303\pm 0.009$ and $\alpha_s^{\rm CI}(m_\tau^2)=0.319\pm 0.012$,
which gives, after evolution to the $Z$ boson mass scale, $\alpha^{\rm
FO}_s(m_Z^2)=0.1165\pm0.0012 $ and $\alpha_s^{\rm CI}(m_Z^2)=0.1185\pm0.0015 $,
respectively. We observe that non-perturbative effects limit the accuracy with
which $\alpha_s$ can be extracted from $\tau$ decay data.

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The categories of this paper are: cs
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The categories of this paper are: q-alg
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The categories of this paper are: eess
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The categories of this paper are: atom-ph
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The categories of this paper are: quant-ph
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The categories of this paper are: hep-th
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The categories of this paper are: physics
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The categories of this paper are: ao-sci
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The categories of this paper are: math
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The categories of this paper are: cmp-lg
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The categories of this paper are: bayes-an
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The categories of this paper are: chao-dyn
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The categories of this paper are: acc-phys
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The categories of this paper are: chem-ph
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The categories of this paper are: q-bio
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The categories of this paper are: plasm-ph