An Estimate of alpha_S from Bottomonium in Unquenched QCD

SESAM Collaboration; A. Spitz; N. Eicker; S. Guesken; H. Hoeber; P. Lacock; T. Lippert; K. Schilling; T. Struckmann; P. Ueberholz; J. Viehoff

doi:10.1016/S0920-5632(99)85062-2

paper

An Estimate of alpha_S from Bottomonium in Unquenched QCD

arXiv:hep-lat/9809130 · doi:10.1016/S0920-5632(99)85062-2

Abstract

We estimate the strong coupling constant from the perturbative expansion of the plaquette. The scale is set by the 2S-1S and 1P-1S splittings in bottomonium which are computed in NRQCD on dynamical gauge configurations with nf=2 degenerate Wilson quarks at intermediate masses. We have increased the statistics of our spectrum calculation in order to reliably extrapolate in the sea-quark mass. We find a value of alpha_MS(m_Z) = 0.1118(26) which is somewhat lower than previous estimates within NRQCD.

LATTICE98(heavyqk)