We present a new determination of the QCD strong coupling constant based on precise lattice calculations of the Υ spectrum. The largest systematic uncertainty in previous such determinations resulted from the absence of vacuum polarization from light quarks. We substantially reduce this error by including two flavors of dynamical light quarks and extrapolating to three. We find \alphathree\V(8.2\GeV)=0.196(3) for three light flavors, corresponding to \alphafive\msbar(MZ)=0.115(2). This is significantly more accurate than previous determinations using this or any other technique.
@article{arxiv.hep-ph/9408328,
title = {A Precise Determination of $\alpha_s$ from Lattice QCD},
author = {C. T. H. Davies and K. Hornbostel and G. P. Lepage and A. Lidsey and J. Shigemitsu and J. Sloan},
journal= {arXiv preprint arXiv:hep-ph/9408328},
year = {2009}
}
Comments
11 pages (LaTeX), OHSTPY-HEP-T-94-013, FSU-SCRI-94-79 (includes minor corrections in tables, additional references)