Application of heavy-quark effective theory to lattice QCD: II. Radiative corrections to heavy-light currents

TL;DR

This paper develops a method using heavy-quark effective theory to compute radiative corrections to heavy-light currents in lattice QCD, enabling more accurate matching to continuum QCD for phenomenological applications.

Contribution

It provides one-loop matching factors for heavy-light currents in lattice QCD, incorporating radiative corrections within the heavy-quark effective theory framework.

Findings

Derived one-loop matching factors for lattice heavy-light currents.

Calculated the Brodsky-Lepage-Mackenzie scale q* for these corrections.

Established a systematic approach for matching lattice QCD to continuum QCD.

Abstract

We apply heavy-quark effective theory to separate long- and short-distance effects of heavy quarks in lattice gauge theory. In this approach, the inverse heavy-quark mass and the lattice spacing are treated as short distances, and their effects are lumped into short-distance coefficients. We show how to use this formalism to match lattice gauge theory to continuum QCD, order by order in the heavy-quark expansion. In this paper, we focus on heavy-light currents. In particular, we obtain one-loop results for the matching factors of lattice currents, needed for heavy-quark phenomenology, such as the calculation of heavy-light decay constants, and heavy-to-light transition form factors. Results for the Brodsky-Lepage-Mackenzie scale $q^*$ are also given.