Heavy Quark Potentials in Quenched QCD at High Temperature

Heavy quark potentials are investigated at high temperatures. The temperature range covered by the analysis extends from T values just below the deconfinement temperature up to about 4Tc in the deconfined phase. We simulated the pure gauge sector of QCD on lattices with temporal extents of 4, 6 and 8 with spatial volumes of 32. On the smallest lattice a tree level improved action was employed while in the other two cases the standard Wilson action was used. Below Tc we find a temperature dependent logarithmic term contributing to the confinement potential and observe a string tension which decreases with rising temperature but retains a finite value at the deconfinement transition. Above Tc the potential is Debye-screened, however simple perturbative predictions do not apply. PACS-Indices : 5.70.Ce 12.38.Gc 12.39.Pn