Analysis of the HELIOS-3 ${\mu }^{+}{\mu }^{-}$ Data within a Relativistic Transport Approach

Abstract

We present a nonperturbative dynamical study of ${\mu }^{+}{\mu }^{-}$ production in proton-nucleus and nucleus-nucleus collisions at SPS energies on the basis of the covariant transport approach HSD. For p + W reactions at 200 GeV bombarding energy the dimuon yield for invariant masses m $\le$ 1.6 GeV is found to be dominated by the decays of the $\eta ,\rho ,\omega$ and $\Phi$ mesons. For 200 GeV/A S + W collisions, however, the dimuon yield shows an additional large contribution from ${\pi }^{+}{\pi }^{-}$, $K^{+}{K}^{-}$ and $\pi \rho$ channels. We find that for `free' meson masses and form factors the experimental cross section is clearly underestimated for S + W in the invariant mass range 0.35 GeV $\le$ m $\le$ 0.65 GeV and that the HELIOS-3 data can only be reproduced within a hadronic scenario, if the $\rho /\omega$-meson mass drops with baryon density. This finding suggests a partial restoration of chiral symmetry in S + W collisions at SPS energies.

11 pages, 5 postscript figures

References in corpus (2)

• Enhancement of low-mass dileptons in heavy-ion collisions
• Dilepton Production at SPS Energies

Cited by in corpus (42)

• Signatures of Quark-Gluon-Plasma formation in high energy heavy-ion collisions: A critical review
• Low-mass e+e- pair production in 158 A GeV Pb-Au collisions at the CERN SPS, its dependence on multiplicity and transverse momentum
• Medium effects in high energy heavy-ion collisions
• Kaon versus Antikaon Production at SIS Energies
• P-Wave Polarization of the $\rho$-Meson and the Dilepton Spectrum in Dense Matter
• e+e--pair production in Pb-Au collisions at 158 GeV per nucleon
• Dilepton production and off-shell transport dynamics at SIS energies
• Strangeness Production in the HSD Transport Approach from SIS to SPS energies
• Dilepton Production from AGS to SPS Energies within a Relativistic Transport Approach
• Dilepton Spectra from Decays of Light Unflavored Mesons
• J/psi suppression in ultrarelativistic nuclear collisions
• Probing the Rho Spectral Function in Hot and Dense Nuclear Matter by Dileptons
• Dilepton production in proton-nucleus and nucleus-nucleus collisions at SPS energies
• K^+ production in the reaction ${}^{58}Ni{+}^{58}Ni$ at incident energies from 1 to 2 AGeV
• Production and absorption of $c\bar{c}$ pairs in nuclear collisions at SPS energies
• $J/\Psi$ suppression in nuclear collisions at SPS energies
• Dilepton production and $m_T$-scaling at BEVALAC/SIS energies
• The spectral function of the omega meson in nuclear matter from a coupled-channel resonance model
• Role of baryonic resonances in the dilepton emission in nucleon-nucleon collisions
• Low-mass dileptons and dropping rho meson mass
• Medium effects in the production and decay of vector mesons in pion-nucleus reactions
• $\rho$-meson properties at finite nuclear density
• Enhancement of low-mass dileptons in SPS heavy-ion collisions: possible evidence for dropping rho meson mass in medium
• Meson $m_T$-scaling in heavy-ion collisions at SIS energies
• Pion electromagnetic form factor at finite temperature
• Perspectives of $e^{+}{e}^{-}$ production in pp, pd and p Be reactions at SIS energies
• e^+e^- production from pp reactions at BEVALAC energies
• Dilepton production in proton-proton collisions at BEVALAC energies
• $e^{+}{e}^{-}$ pairs from ${\pi }^{-}$A reactions
• Medium effects in the production and decay of $\omega$- and $\rho$-resonances in pion-nucleus interactions
• Hadrons in the Nuclear Medium
• $\rho$-Meson Production and Decay in Proton-Nucleus Collisions
• $e^{+}{e}^{-}$ production in $pA$ reactions at SIS energies
• ${\pi }^{+}{\pi }^{-}$ Emission from Coherent ${\rho }^0$ Propagation in Nuclei
• Temperature dependence of cross sections for meson-meson nonresonant reactions in hadronic matter
• Low energy ω(\to π^0 γ) meson photoproduction in the nucleus
• Broadening of $\rho (\to e^{+}{e}^{-})$ meson produced coherently in the photonuclear reaction
• Photon production in heavy-ion collisions at SPS energies
• Hadron Formation Time and Dilepton Mass Spectra in Heavy Ion Collisions
• Highlights on Dilepton and Photon Observables
• Electromagnetic probes of dense matter in heavy-ion collisions
• Dilepton production at SIS energies