Matching lattice and continuum axial-vector and vector currents with NRQCD and HISQ quarks

TL;DR

This paper performs a one-loop perturbative matching of continuum and lattice axial-vector and vector currents using NRQCD for heavy quarks and HISQ for light quarks, including renormalisation for massless and massive cases.

Contribution

It provides the first detailed one-loop matching calculations for these currents combining NRQCD and HISQ actions, including renormalisation parameters.

Findings

Successful one-loop matching of currents with NRQCD and HISQ

Results applicable to both massless and massive HISQ quarks

Includes detailed renormalisation parameters for HISQ

Abstract

We match the continuum and lattice axial vector and vector currents at one loop in perturbation theory. For the heavy quarks we use the nonrelativistic QCD (NRQCD) action and for the light quarks the Highly Improved Staggered Quark (HISQ) action. We present results for both massless and massive HISQ quarks and as part of the matching procedure we include a discussion of the one loop HISQ renormalisation parameters.