PUB - Publikationen an der Universität Bielefeld

We study light valence quark Euclidean correlation functions in finite temperature lattice QCD. The calculations have been performed in quenched lattice QCD at T ~ 1.45Tc for four values of the lattice cut-off on lattices up to size 128^3 × 48. This allows to perform a continuum extrapolation of the correlation function in the Euclidean time interval 0.2 <= T <= 0.5 to better than 1% accuracy. Additionally we study the temperature dependence of our results on 128^3 × 40, 32 and 16 lattices cor- responding to the temperatures T ~ 1.2, 1.45 and 3.0Tc, as well as the momentum dependence in the vector case at T ~ 1.45Tc on a lattice sized 128^3 × 48. Subsequently we compute the first two non- vanishing thermal moments of the vector and pseudo scalar meson spectral functions on all lattices. Using the constraints gained by our data analysis, we then proceed to extract information on the spectral representation of the vector correlator and discuss resulting consequences for the electrical conductivity and the thermal dilepton rate in the plasma phase. Finally we discuss the spectral function of the pseudo scalar and examine renormalization errors using the degeneracy conditions of the symmetry restored plasma phase of QCD.