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Dilepton production in proton-nucleus and nucleus-nucleus collisions at SPS energies

G. Q. Li·C. M. Ko·G. E. Brown·H. Sorge
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Abstract

Dilepton production in proton- and nucleus-induced reactions is studied in 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 and direct vector meson decay. However, to provide a quantitative explanation of the 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 and dense medium, we find that these heavy-ion data can also be satisfactorily explained. This agrees with our earlier conclusions based on a fire cylinder model. We also give predictions for Pb+Au collisions at 160 GeV/nucleon using current CERES mass resolution and acceptance.

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G. Q. Li, C. M. Ko, G. E. Brown, H. Sorge. 1996-11-18. Dilepton production in proton-nucleus and nucleus-nucleus collisions at SPS energies. https://doi.org/10.1016/s0375-9474(96)00318-1

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