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Applying Optimized Perturbation Theory to QCD at Low Energies

A. C. Mattingly·P. M. Stevenson
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Abstract

We discuss the use of the optimization procedure based on the Principle of Minimal Sensitivity to the third-order calculation of {\mbox{${R_{e^+e^-}}$}}. The effective coupling constant remains finite allowing us to apply the Poggio-Quinn-Weinberg smearing method down to energies below 1 GeV, where we find good agreement between theory and experiment. The couplant freezes to a value of $α_s/π= 0.26$ at zero energy which is in remarkable concordance with values obtained phenomenologically.

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A. C. Mattingly, P. M. Stevenson. 1992-12-07. Applying Optimized Perturbation Theory to QCD at Low Energies. https://arxiv.org/abs/hep-ph/9212231

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