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 4T₂ 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 32^3. On the smallest lattice a tree level improved action was employed, while in the other two cases the standard Wilson action was used. Below T₂ 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 T₂ the potential is Debye screened; however, simple perturbative predictions do not apply.