Quarkonium mass splittings in three-flavor lattice QCD

TL;DR

This paper presents lattice QCD calculations of charmonium and bottomonium mass splittings using three-flavor ensembles, testing the accuracy of lattice QCD and heavy-quark discretization effects, with results largely consistent with experimental data.

Contribution

First detailed lattice QCD study of quarkonium splittings with three-flavor sea quarks using the Fermilab approach for heavy quarks.

Findings

Results agree with experimental measurements after error analysis.

Discretization errors are well-understood and controlled.

Provides validation of lattice QCD methods for heavy quark systems.

Abstract

We report on calculations of the charmonium and bottomonium spectrum in lattice QCD. We use ensembles of gauge fields with three flavors of sea quarks, simulated with the asqtad improved action for staggered fermions. For the heavy quarks we employ the Fermilab interpretation of the clover action for Wilson fermions. These calculations provide a test of lattice QCD, including the theory of discretization errors for heavy quarks. We provide, therefore, a careful discussion of the results in light of the heavy-quark effective Lagrangian. By and large, we find that the computed results are in agreement with experiment, once parametric and discretization errors are taken into account.