Dynamical quark effects on heavy-quark spin-dependent potential in lattice QCD

Abstract

A full QCD simulation was carried out for the spin-dependent force for the heavy quark spectroscopy using the Kogut-Susskind quark action with the gauge coupling β=5.6 on a 10 3×20 lattice at m q a=0.1 and 0.05. The effect of vacuum quark loops on the spin-dependent potential is absorbed into the shift of the bare gauge coupling. This implies that the spin-dependent potential would be still insufficient to describe the excited spectra of J/Ψ and ϒ families in terms of the non-relativistic potential model, contrary to the conjecture sometimes made in the literature. The present result ensures that the inclusion of the vacuum quark loop does not affect the mass splitting patterns of hadron multiplets in the quenched calculation.