Enhancement of low-mass dileptons in SPS heavy-ion collisions: possible evidence for dropping rho meson mass in medium
Abstract
Dilepton production in proton- and nucleus-induced reactions at SPS energies is studied in the relativistic transport model using initial conditions determined by the string dynamics from RQMD. It is found that both the CERES and HELIOS-3 data for dilepton spectra in proton-nucleus reactions can be well described by the conventional mechanism of Dalitz decay observed dilepton spectra in central S+Au and S+W collisions requires contributions other than these direct decays. Introducing a decrease of vector meson masses in hot dense medium, we find that these heavy-ion data can also be satisfactorily explained. We also give predictions for Pb+Au collisions at 160 GeV/nucleon using current CERES mass resolution and acceptance.
- Publication:
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Nuclear Physics A
- Pub Date:
- February 1996
- DOI:
- 10.1016/S0375-9474(96)00368-5
- arXiv:
- arXiv:nucl-th/9609008
- Bibcode:
- 1996NuPhA.610..342K
- Keywords:
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- Nuclear Theory
- E-Print:
- 8 pages, LaTeX, figures available from gqli@comp.tamu.edu, contribution to QM'96, to appear in the proceedings