αS from the Lattice Potential

Abstract We present an extensive study on the direct determination of the running coupling αs from the static quark antiquark force at short distances, in quenched QCD. We find from our high statistics potential analysis that α q q exhibits two-loop asymptotic behavior for momenta as low as .5 GeV. As a reult, we determine the zero flavour Λ-parameter to be Λ (0) MS = .630(38) δ = 293(18) +25 −63 MeV . A rough estimate of full QCD effects leads to the five flavour value α MS (mZ)=.102 +6 −11 . A comparison with other lattice results is made.