A Lattice Calculation of Thermal Dilepton Rates
Abstract
Using clover improved Wilson fermions we calculate thermal vector meson correlation functions above the deconfinement phase transition of quenched QCD. At temperatures 1.5 Tc and 3Tc they are found to differ by less than 15% from that of a freely propagating quark anti-quark pair. This puts severe constraints on the dilepton production rate and in particular rules out a strong divergence of the dilepton rate at low energies. The vector spectral function, which has been reconstructed using the Maximum Entropy Method, yields an enhancement of the dilepton rate over the Born rate of at most a factor two in the energy interval 4 < E/T < 8 and suggests that the spectrum is cut-off at low energies by a thermal mass threshold of about (2-3)T.
Keywords
Cite
@article{arxiv.hep-lat/0110208,
title = {A Lattice Calculation of Thermal Dilepton Rates},
author = {F. Karsch and E. Laermann and P. Petreczky and S. Stickan and I. Wetzorke},
journal= {arXiv preprint arXiv:hep-lat/0110208},
year = {2009}
}
Comments
9 pages, LaTeX2e File, 5 EPS files; minor corrections, modified error bins in Fig.2a