Non-perturbative tests of Heavy Quark Effective Theory

We consider QCD with one massless quark and one heavy quark in a finitevolume of linear extent L_0 ~ 0.2 fm. In this situation, HQET represents anexpansion in terms of 1/z=1/(m L_0), which we test by a non-perturbativecomputation of quenched current matrix elements and energies, taking thecontinuum limit of lattice results. These are seen to approach thecorresponding renormalization group invariant matrix elements of the staticeffective theory as the quark mass becomes large. We are able to obtainestimates of the size of the 1/m-corrections to the static theory, which arealso of practical relevance in our recent strategy to implement HQETnon-perturbatively by matching to QCD in a finite volume.Comment: 28 pages including figures and tables, latex2e, uses JHEP3.cls; version published in JHEP, small additions and typos corrected, results unchange