Improved lattice fermion action for heavy quarks

TL;DR

This paper introduces an improved lattice fermion action for heavy quarks using Brillouin-type fermions, achieving better energy-momentum relations and reduced discretization errors, with demonstrated benefits in charmonium calculations.

Contribution

The paper develops a new Brillouin-type fermion action that reduces discretization errors and improves energy-momentum dispersion for heavy quarks on the lattice.

Findings

Enhanced energy-momentum dispersion relation for heavy quarks.

Reduced discretization errors at tree-level.

Better agreement with continuum physics compared to Wilson and domain-wall fermions.

Abstract

We develop an improved lattice action for heavy quarks based on Brillouin-type fermions, that have excellent energy-momentum dispersion relation. The leading discretization errors of $O(a)$ and $O(a^2)$ are eliminated at tree-level. We carry out a scaling study of this improved Brillouin fermion action on quenched lattices by calculating the charmonium energy-momentum dispersion relation and hyperfine splitting. We present a comparison to standard Wilson fermions and domain-wall fermions.