Lattice implementation of the Isgur-Wise limit

We construct the Isgur-Wise limit of QCD in a form appropriate for measurement by lattice-gauge-theory techniques. The coordinate-space fermion propagator in the presence of a background gauge field has a systematic expansion in powers of the inverse quark mass about the Isgur-Wise limit. The formulation permits a calculation of heavy-quark processes even when the momentum transfers are much larger than the inverse lattice spacing. Applications include semileptonic heavy-quark decay and scattering processes, including the computation of the nonperturbative part of the Isgur-Wise universal function.