We study the Wilson line correlation function in Coulomb gauge on lattices in 2+1 flavor QCD with the aim to determine the complex potential at non-zero temperature and present past results on coarse lattices along with some preliminary results on newly generated fine lattices.
From the analysis of the Wilson line correlation function after the subtraction of a temperature independent UV part we conclude that the corresponding spectral function is well described by a dominant peak.
If a potential interpretation is applicable, the peak position and effective width correspond to the potential's real and imaginary parts.
We positively confirm this potential interpretation with a peak position that is temperature independent and shows no sign of screening, while the peak width shows a strong temperature dependence.