Onium Masses with Three Flavors of Dynamical Quarks

TL;DR

This paper extends previous calculations of the charmonium spectrum using three-flavor dynamical quark ensembles, finding reasonable agreement with observed masses but noting some discrepancies in spin splittings.

Contribution

It presents an improved calculation of the charmonium spectrum with three-flavor dynamical quarks using updated ensembles and the Fermilab formulation for heavy quarks.

Findings

Charmonium masses agree reasonably with experimental data.

Some spin splittings remain smaller than observed.

Utilizes recent MILC collaboration ensembles.

Abstract

We have greatly extended an earlier calculation of the charmonium spectrum on three flavor dynamical quark ensembles by using more recent ensembles generated by the MILC collaboration. The heavy quarks are treated using the Fermilab formulation. The charmonium state masses are in reasonable agreement with the observed spectrum; however, some of the spin splittings may still be too small.