Coulomb resummation for system near threshold and precision determination of αs and mb

Abstract We analyze sum rules for the Ψ system with resummation of threshold effects on the basis of the non-relativistic Coulomb approximation. We find for the pole mass of the bottom quark m b = 4.75 ± 0.04 GeV and for the strong coupling constant α s ( M z ) = 0.118 ± 0.006. The origin of the contradiction between two recent estimates obtained within the same formal framework is clarified.