α_s from the Lattice Hadronic Vacuum Polarisation

2018/04/26 by Hudspith, Renwick J., Lewis, Randy, Maltman, Kim +1
#FOS: Physical sciences #High Energy Physics - Lattice (hep-lat) #High Energy Physics - Phenomenology (hep-ph)

paper · doi:10.48550/arxiv.1804.10286

Abstract

We present a determination of the QCD coupling constant, α_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 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 MS coupling the value α_s(M_Z)=0.1181(27)⁺⁸_-22, where the first error is statistical and the second systematic.

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