SPIN DEPENDENCE OF THE HEAVY-QUARK POTENTIAL - A QCD LATTICE ANALYSIS

We have investigated the spin dependence of the potential between heav y quarks in full lattice QCD, including the effects of light quark loo ps. The form of the spin-orbit, the tensor and the spin-spin forces pr esent clear evidence for long-range scalar confinement supplemented by a Coulomb force at short distances. This agrees with observations fro m quarkonium spectroscopy. The QCD simulation has been carried out for Kogut-Susskind fermions with four degrees of freedom at a gauge coupl ing beta = 5.35 and a quark mass am(q) = 0.01 on a 16(3) x 24 size lat tice. This corresponds to a lattice spacing 0.12 fm, a spatial lattice size of about 2 fm and a light quark mass of 48 MeV.