Determination of $M_b$ and ${\alpha }_s$ from the Upsilon System

Abstract

The mass of the bottom quark (both the pole mass $M_b$ and the $\text{MSb}$ mass $m_b$) and the strong coupling constant ${\alpha }_s$ have been determined from QCD moment sum rules for the ${\rm Y}$ system. In the pole-mass scheme large perturbative corrections resulting from coulombic contributions have been resummed. The results of this analysis are: $M_b=4.60\pm 0.02\text{gev}$, $m_b(m_b)=4.13\pm 0.06\text{gev}$ and ${\alpha }_s(M_Z)=0.119\pm 0.008$.

Comments: 5 pages, 1 Postscript figure Invited talk at the High Energy Conference on Quantum Chromodynamics (QCD'97), Montpellier, July 1997