The Mass of the b Quark from Lattice NRQCD

Abstract

We present results for the mass of the $b$ quark in the $\overline{MS}$ scheme obtained by calculating the binding energy of the $B$ meson in the static limit. The self energy of a static quark, $E_0^{\infty }$ needed for this purpose, is now known to $O({\alpha }^3)$ in the quenched approximation. We find a {\it preliminary} value of $\overline{m_b}(\overline{m_b})=4.34(7)$ GeV at $n_f=0$. The error is dominated by the remaining uncertainty in $E_0^{\infty }$. In addition, using $E_0^{\infty }$ at $O({\alpha }^2)$, we estimate that the quark mass is reduced by approximately 70 MeV when two flavours of dynamical quarks are introduced.

3 pages, talk presented at the 4th International conference on ``Quark Confinement and the Hadron Spectrum'' on 3rd-8th July, 2000 in Vienna, Austria. Replacement to correct typo in table 2