Determination of Mb and αs from the upsilon system

Abstract

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