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arXiv · 1804.10286

$\alpha_s$ from the Lattice Hadronic Vacuum Polarisation

Renwick J. Hudspith·Randy Lewis·Kim Maltman·Eigo Shintani
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Abstract

We present a determination of the QCD coupling constant, $\alpha_s$, obtained by fitting lattice results for the flavour $ud$ hadronic vacuum polarisation function to continuum perturbation theory. We use $n_f=2+1$ flavours of Domain Wall fermions generated by the RBC/UKQCD collaboration and three lattice spacings $a^{-1}=1.79,\, 2.38$ and $3.15\ \text{GeV}$. Several sources of potential systematic error are identified and dealt with. After fitting and removing expected leading cut-off effects, we find for the five-flavour $\overline{\text{MS}}$ coupling the value $\alpha_s(M_Z)=0.1181(27)^{+8}_{-22}$, where the first error is statistical and the second systematic.

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Renwick J. Hudspith, Randy Lewis, Kim Maltman, Eigo Shintani. 2018-04-26. $\alpha_s$ from the Lattice Hadronic Vacuum Polarisation. https://arxiv.org/abs/1804.10286

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