  The current-current correlator method has been used successfully to obtain
very accurate results for quark masses and the coupling alpha_s. The
calculations were done using Highly Improved Staggered Quarks (HISQ) and
heavy-heavy meson correlators. We now extend this work to the significantly
more challenging heavy-light case, reporting the first results here. The aim is
to determine nonperturbative Z factors for NRQCD heavy-light currents, but
first we test the method in the HISQ case where Z=1.
