Low-mass dileptons at the CERN-SpS: evidence for chiral restoration?
R. Rapp1 - J. Wambach2
1 Department of Physics and Astronomy, State University of New York, Stony Brook, NY
2 Institut für Kernphysik, TU Darmstadt, Schlossgartenstr. 9, 64289 Darmstadt, Germany
Received: 30 September 1999 Communicated by B. Povh
Using a rather complete description of the in-medium spectral function - being constrained by various independent experimental information - we calculate pertinent dilepton production rates from hot and dense hadronic matter. The strong broadening of the resonance entails a reminiscence to perturbative annihilation rates in the vicinity of the phase boundary. The application to dilepton observables in Pb(158AGeV)+Au collisions - incorporating recent information on the hadro-chemical composition at CERN-SpS energies - essentially supports the broadening scenario. Possible implications for the nature of chiral symmetry restoration are outlined.
12.40.Vv Vector-meson dominance - 21.65.+f Nuclear matter