# Matching heavy-quark fields in QCD and HQET at three loops - High Energy Physics - Phenomenology

Abstract: The relation between the heavy-quark field in QCD and the corresponding fieldin HQET is derived up to three loops, and to all orders in the large-$\beta 0$limit. The corresponding relation between the QED electron field and theBloch-Nordsieck one is gauge invariant to all orders. We also prove that the$\bar{\text{MS}}$ anomalous dimension of the QED electron field depends on thegauge parameter only at one loop.

Author: A. G. Grozin

Source: https://arxiv.org/