HQET at order 1/m: I. Non-perturbative parameters in the quenched approximation

TL;DR

This paper non-perturbatively determines parameters of lattice HQET including 1/m corrections, enabling precise calculations of heavy-light meson properties in the quenched approximation.

Contribution

It provides the first non-perturbative determination of HQET parameters at order 1/m in the quenched approximation, separating universal and non-universal parts.

Findings

Parameters for HQET Lagrangian and current determined non-perturbatively.

Results enable computation of heavy-light spectrum and B-meson decay constants.

Uses plaquette gauge action and HYP1/2 b-quark action with non-perturbative O(a)-improved Wilson light quarks.

Abstract

We determine non-perturbatively the parameters of the lattice HQET Lagrangian and those of the time component of the heavy-light axial-vector current in the quenched approximation. The HQET expansion includes terms of order 1/m. Our results allow to compute, for example, the heavy-light spectrum and B-meson decay constants in the static approximation and to order 1/m in HQET. The determination of the parameters is separated into universal and non-universal parts. The universal results can be used to determine the parameters for various discretizations. The computation reported in this paper uses the plaquette gauge action and the "HYP1/2" action for the b-quark described by HQET. The parameters of the current also depend on the light-quark action, for which we choose non-perturbatively O(a)-improved Wilson fermions.