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Dilepton Production from AGS to SPS Energies within a Relativistic Transport Approach
We present a nonperturbative dynamical study of $e^+e^-$ production in proton-nucleus and nucleus-nucleus collisions from AGS to SPS energies on the basis of the covariant transport approach HSD. For p + Be reactions the dilepton yield for invariant masses $M \leq 1.4$ GeV is found to be dominated b...
Autores principales: | , |
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Lenguaje: | eng |
Publicado: |
1996
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Materias: | |
Acceso en línea: | https://dx.doi.org/10.1016/S0375-9474(97)00140-1 http://cds.cern.ch/record/315323 |
_version_ | 1780890339901440000 |
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author | Bratkovskaya, E L Cassing, W |
author_facet | Bratkovskaya, E L Cassing, W |
author_sort | Bratkovskaya, E L |
collection | CERN |
description | We present a nonperturbative dynamical study of $e^+e^-$ production in proton-nucleus and nucleus-nucleus collisions from AGS to SPS energies on the basis of the covariant transport approach HSD. For p + Be reactions the dilepton yield for invariant masses $M \leq 1.4$ GeV is found to be dominated by the decays of the $\eta, \rho, \omega$ and $\Phi$ mesons at all energies from 10 -- 450 GeV. For nucleus-nucleus collisions, however, the dilepton yield shows an additional large contribution from $\pi^+\pi^-$, $K^+K^-$ and $\pi scenario in comparison to a 'dropping' meson mass scenario at finite baryon density. We find that for 'dropping' meson masses the invariant dilepton mass range 0.35 GeV $\leq M \leq$ 0.65 GeV is increased in comparison to the 'free' meson mass scenario and that the data of the CERES-collaboration for nucleus-nucleus collisions can be described much better within the 'dropping' mass scheme. We study in detail the contributions from the various dilepton channels as a function of the transverse momentum and rapidity of the lepton pair as well as a function of the charged particle multiplicity. Furthermore, various direct photon channels for S + Au at 200 GeV/u are computed and found to be well below the upper bounds measured by the WA80-collaboration. |
id | cern-315323 |
institution | Organización Europea para la Investigación Nuclear |
language | eng |
publishDate | 1996 |
record_format | invenio |
spelling | cern-3153232019-09-30T06:29:59Zdoi:10.1016/S0375-9474(97)00140-1http://cds.cern.ch/record/315323engBratkovskaya, E LCassing, WDilepton Production from AGS to SPS Energies within a Relativistic Transport ApproachNuclear Physics - TheoryWe present a nonperturbative dynamical study of $e^+e^-$ production in proton-nucleus and nucleus-nucleus collisions from AGS to SPS energies on the basis of the covariant transport approach HSD. For p + Be reactions the dilepton yield for invariant masses $M \leq 1.4$ GeV is found to be dominated by the decays of the $\eta, \rho, \omega$ and $\Phi$ mesons at all energies from 10 -- 450 GeV. For nucleus-nucleus collisions, however, the dilepton yield shows an additional large contribution from $\pi^+\pi^-$, $K^+K^-$ and $\pi scenario in comparison to a 'dropping' meson mass scenario at finite baryon density. We find that for 'dropping' meson masses the invariant dilepton mass range 0.35 GeV $\leq M \leq$ 0.65 GeV is increased in comparison to the 'free' meson mass scenario and that the data of the CERES-collaboration for nucleus-nucleus collisions can be described much better within the 'dropping' mass scheme. We study in detail the contributions from the various dilepton channels as a function of the transverse momentum and rapidity of the lepton pair as well as a function of the charged particle multiplicity. Furthermore, various direct photon channels for S + Au at 200 GeV/u are computed and found to be well below the upper bounds measured by the WA80-collaboration.nucl-th/9611042UGI-96-25oai:cds.cern.ch:3153231996-11-20 |
spellingShingle | Nuclear Physics - Theory Bratkovskaya, E L Cassing, W Dilepton Production from AGS to SPS Energies within a Relativistic Transport Approach |
title | Dilepton Production from AGS to SPS Energies within a Relativistic Transport Approach |
title_full | Dilepton Production from AGS to SPS Energies within a Relativistic Transport Approach |
title_fullStr | Dilepton Production from AGS to SPS Energies within a Relativistic Transport Approach |
title_full_unstemmed | Dilepton Production from AGS to SPS Energies within a Relativistic Transport Approach |
title_short | Dilepton Production from AGS to SPS Energies within a Relativistic Transport Approach |
title_sort | dilepton production from ags to sps energies within a relativistic transport approach |
topic | Nuclear Physics - Theory |
url | https://dx.doi.org/10.1016/S0375-9474(97)00140-1 http://cds.cern.ch/record/315323 |
work_keys_str_mv | AT bratkovskayael dileptonproductionfromagstospsenergieswithinarelativistictransportapproach AT cassingw dileptonproductionfromagstospsenergieswithinarelativistictransportapproach |