PUB - Publikationen an der Universität Bielefeld

We present new results on the reconstruction of mesonic spectral functionsfor three temperatures $1.1T_c$, $1.2T_c$ and $1.4T_c$ in quenched QCD. Makinguse of non-perturbatively improved clover Wilson valence quarks allows for aclean extrapolation of correlator data to the continuum limit. For the case ofvanishing momentum the spectral function is obtained by fitting the data to awell motivated ansatz, using the full covariance matrix of the continuumextrapolated data in the fit. We found that vector correlation function isalmost temperature independent in the current temperature window. Theelectrical conductivity of the hot medium, related to the origin of the vectorspectral function at zero momentum, is computed from the resulting parametersat all three temperatures, leading to an estimate of $0.2C_{em}\lesssim\sigma/T\lesssim0.4C_{em}$. The dilepton rates resulting from the obtained spectral functions show no significant temperature dependence.