Lambda-bar, lambda_1 and m_b in three-flavor (lattice) QCD

Abstract

The heavy-quark expansion for inclusive semi-leptonic B decays introduces $\bar{\Lambda}$ and $\lambda_1$, which are matrix elements in heavy-quark effective field theory. We review how they can be obtained from an analysis of the heavy quark mass dependence of heavy-light meson masses in lattice QCD. We present preliminary results for the bottom quark mass, $m_b$, using $\bar{\Lambda}$ and $\lambda_1$ for the $B_s$ meson from a 2+1 sea-flavor unquenched calculation.