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arXiv · 1611.05750

The determination of $α_s$ by the ALPHA collaboration

Mattia Bruno·Mattia Dalla Brida·Patrick Fritzsch·Tomasz Korzec·Alberto Ramos·Stefan Schaefer·Hubert Simma·Stefan Sint·Rainer Sommer
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Abstract

We review the ALPHA collaboration strategy for obtaining the QCD coupling at high scale. In the three-flavor effective theory it avoids the use of perturbation theory at $α> 0.2$ and at the same time has the physical scales small compared to the cutoff $1/a$ in all stages of the computation. The result $Λ_\overline{MS}^{(3)}=332(14)$~MeV is translated to $α_\overline{MS}(m_Z)=0.1179(10)(2)$ by use of (high order) perturbative relations between the effective theory couplings at the charm and beauty quark "thresholds". The error of this perturbative step is discussed and estimated as $0.0002$.

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Mattia Bruno, Mattia Dalla Brida, Patrick Fritzsch, Tomasz Korzec, Alberto Ramos, Stefan Schaefer, Hubert Simma, Stefan Sint, Rainer Sommer. 2016-11-17. The determination of $α_s$ by the ALPHA collaboration. https://arxiv.org/abs/1611.05750

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