Coulomb resummation for $b\bar{b}$ system near threshold and precision determination of ${\text{al}}_s$ and $m_b$.

Abstract

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

Comments: 22 pages Latex, some misprints in the Appendix are corrected