We compute the matching coefficients between QCD and non-relativistic QCD for external vector, axial-vector, scalar and pseudo-scalar currents up to three-loop order. We concentrate on the non-singlet contributions and present precise numerical results with an accuracy of about ten digits. For the vector current the results from arXiv:1401.3004 are confirmed, increasing the accuracy by several orders of magnitude.
@article{arxiv.2203.11231,
title = {Three-loop non-singlet matching coefficients for heavy quark currents},
author = {Manuel Egner and Matteo Fael and Fabian Lange and Kay Schönwald and Matthias Steinhauser},
journal= {arXiv preprint arXiv:2203.11231},
year = {2022}
}