Parameters of Heavy Quark Effective Theory from Nf=2 lattice QCD

TL;DR

This paper non-perturbatively determines the parameters of lattice Heavy Quark Effective Theory (HQET) with Nf=2 dynamical quarks, covering a range of heavy quark masses from charm to beyond beauty, to improve calculations of heavy-light systems.

Contribution

It provides the first non-perturbative determination of HQET parameters for Nf=2 lattice QCD at order 1/mh, applicable to heavy-light meson calculations.

Findings

HQET parameters determined non-perturbatively

Applicable to b-quark mass and decay constants

Uses multiple static actions for validation

Abstract

We report on a non-perturbative determination of the parameters of the lattice Heavy Quark Effective Theory (HQET) Lagrangian and of the time component of the heavy-light axial-vector current with Nf=2 flavors of massless dynamical quarks. The effective theory is considered at the 1/mh order, and the heavy mass mh covers a range from slightly above the charm to beyond the beauty region. These HQET parameters are needed to compute, for example, the b-quark mass, the heavy-light spectrum and decay constants in the static approximation and to order 1/mh in HQET. The determination of the parameters is done non-perturbatively. The computation reported in this paper uses the plaquette gauge action and two different static actions for the heavy quark described by HQET. For the light-quark action we choose non-perturbatively O(a)-improved Wilson fermions.