Abstract
We compute the radiation of dileptons and photons using relativistic hydrodynamics and a coarse-grained version of the microscopic event generator UrQMD, both of which provide a good description of the hadron spectra. The currently most accurate dilepton and photon emission rates from perturbative QCD and from experimentally-based hadronic calculations are used. Comparisons are made to data on central Pb-Pb and Pb-Au collisions taken at the CERN SPS at a beam energy of 158 A GeV. Both hydrodynamics and UrQMD provide very good descriptions of the photon transverse momentum spectrum measured between 1 and 4 GeV, but very slightly underestimate the low mass spectrum of e +e- pairs, even with greatly broadened ρ and ω vector mesons.
Original language | English (US) |
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Pages (from-to) | 709c-712c |
Journal | Nuclear Physics A |
Volume | 715 |
DOIs | |
State | Published - Mar 10 2003 |
Bibliographical note
Funding Information:*This work was done in collaboration was supported by the US Department