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On the role of the quark mass thresholds in extrapolations of the running α_s

Jiri Chyla
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Abstract

The accuracy of the conventional treatment of quark mass thresholds in the QCD running coupling constant $α_s$, based on the step approximation to the $β$--function, is investigated. The errors of extrapolating $\ase(μ)$ from low energies to $μ=M_Z$, implied by this approximation, are shown to be of the same magnitude as the typical next--to--next--to--leading order contributions to \as and tend to increase the resulting \as. The importance of the proper choice of matching points is emphasized.

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Jiri Chyla. 1995-01-12. On the role of the quark mass thresholds in extrapolations of the running α_s. https://doi.org/10.1016/0370-2693(95)00384-w

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