Computation of Λ̄ and λ1 with lattice QCD

We pursue a new method, based on lattice QCD, for determining the quantities Λ̄, λ1, and λ2 of heavy-quark effective theory. We combine Monte Carlo data for the meson mass spectrum with perturbative calculations of the short-distance behavior, to extract Λ̄ and λ1 from a formula from HQET. Taking into account uncertainties from fitting the mass dependence and from taking the continuum limit, we find Λ̄=0.68+0.02−0.12 GeV and λ1=−(0.45±0.12) GeV2 in the quenched approximation.