Heavy quark expansion parameters from lattice NRQCD

Abstract

We present a lattice QCD calculation of the heavy quark expansion parameters [Formula Presented] and [Formula Presented] for heavy-light mesons and heavy-light-light baryons. The calculation is carried out on a [Formula Presented] lattice at [Formula Presented] in the quenched approximation, using the lattice NRQCD action for heavy quarks. We obtain the parameters [Formula Presented] and [Formula Presented] in two different methods: a direct calculation of the matrix elements and an indirect calculation through the mass spectrum, and confirm that both the methods give consistent results. We also discuss an application to the lifetime ratios. © 2004 The American Physical Society.