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arXiv · hep-ph/9508233

Dilepton Production at SPS Energies

W. Cassing·W. Ehehalt·C. M. Ko
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Abstract

We present a nonperturbative dynamical study of $e^+e^-$ production in proton- nucleus and nucleus-nucleus collisions at SPS energies on the basis of a covariant transport approach. For p + A reactions the dilepton yield for invariant masses m $\leq $ 1.2 GeV is found to be dominated by the decays of the $η, ρ, ω$ and $Φ$ mesons in line with the findings of the CERES collaboration. For S + Au collisions at 200 GeV/A the dilepton yield is, however, dominated by $π^+π^-$ annihilation due to the high pion densities achieved. Whereas for `free' meson masses and form factors the experimental cross section is slightly underestimated for 0.3 GeV $\leq$ m $\leq$ 0.45 GeV, different medium modifications of the $ρ$-meson appear compatible with current CERES data.

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W. Cassing, W. Ehehalt, C. M. Ko. 1995-08-04. Dilepton Production at SPS Energies. https://doi.org/10.1016/0370-2693(95)01214-b

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