Coulomb resummation for $b \bar b$ system near threshold and precision determination of $\al_s$ and $m_b$.

We analyze sum rules for the $Υ$ system with resummation of threshold effects on the basis of the nonrelativistic Coulomb approximation. We find for the pole mass of the bottom quark $m_b=4.75\pm 0.04 GeV$ and for the strong coupling constant $\al_s(M_Z)=0.118\pm 0.006$. The origin of the contradiction between two recent estimates obtained within the same formal framework is clarified.

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