A new framework to tune an improved relativistic heavy-quark action

TL;DR

This paper presents a novel non-perturbative method for tuning parameters of a relativistic heavy-quark action, improving precision in heavy-quark physics simulations using lattice QCD.

Contribution

The paper introduces a new non-perturbative tuning framework for the RHQ action using suitable observables and interpolation, enhancing accuracy over previous methods.

Findings

Precise determination of RHQ coefficients achieved.

Application to bottom quark spectroscopy demonstrated.

Method validated across multiple lattice spacings.

Abstract

We introduce a new non-perturbative method to tune the parameters of the Columbia formulation of an anisotropic, clover-improved relativistic heavy-quark (RHQ) action. By making use of suitable observables which can be computed at a sequence of heavy-quark mass values, employing an $O(a)$-improved discretized action with domain-wall chiral fermion, and safely interpolated between the accessible heavy-quark mass region and the static point predicted by heavy-quark effective theory, we are able to precisely determine the unknown coefficients of the RHQ action. In this proof-of-principle study we benefit from the RBC/UKQCD Iwasaki gauge configurations with $2+1$ flavors of dynamical quarks, at three values of the lattice spacing varying from $0.11$ to $0.062$ fm. Preliminary results and applications to bottom spectroscopy are also presented.