Sensitivity of electromagnetic spectra to equation of state and initial energy density in the Pb+Pb collisions at SPS

Abstract

We study Pb+Pb collisions at 158 A GeV/c using a hydrodynamical approach. We test different equations of state (EoSs) and different initial conditions and show that there are more than one initial state for each EoS which reproduce the observed hadronic spectra. We also find that different equations of state favour different freeze-out temperature. Simultaneously we calculate the thermal dilepton and photon spectra for each EoS and initial state. We compare the dilepton mass spectrum to data measured by the CERES collaboration and find that the differences in spectra obtained using different EoSs and initial states are not resolvable within the current experimental resolution. However, at invariant masses over 2 GeV the difference in the yield due to various initial states is close to an order of magnitude. We also study the rapidity distribution of lepton pairs and find that for masses around 800 MeV the shape of the distribution depends strongly on the EoS.

20 pages, 17 figures, LaTeX using elsart.sty; introduction rewritten to clarify the aim of the paper, references added; accepted for publication in Nuclear Physics A

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Cited by in corpus (26)

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• Causal Theories of Dissipative Relativistic Fluid Dynamics for Nuclear Collisions
• Hydrodynamic Models for Heavy Ion Collisions
• Dense Nuclear Matter Equation of State from Heavy-Ion Collisions
• Relativistic Heavy-Ion Collisions within 3-Fluid Hydrodynamics: Hadronic Scenario
• Hydrodynamic afterburner for the Color Glass Condensate and the parton energy loss
• Thermal Photons and Lepton Pairs from Quark Gluon Plasma and Hot Hadronic Matter
• Direct Photons from Relativistic Heavy-Ion Collisions
• RHIC-tested predictions for low-$p_T$ and high-$p_T$ hadron spectra in nearly central Pb+Pb collisions at the LHC
• Photon emission in heavy ion collisions at the CERN SPS
• Dileptons and Photons from Coarse-Grained Microscopic Dynamics and Hydrodynamics Compared to Experimental Data
• Sensitivity of Au+Au collisions to the symmetric nuclear matter equation of state at 2 -- 5 nuclear saturation densities
• Dynamical Freeze-out in 3-Fluid Hydrodynamics
• Elliptic flow of thermal photons in heavy-ion collisions at Relativistic Heavy Ion Collider and Large Hadron Collider
• Dimuon radiation at the CERN SPS within a (3+1)d hydrodynamic+cascade model
• Dependence of hadron spectra on decoupling temperature and resonance contributions
• Freeze-Out Parameters in Central 158AGeV Pb+Pb Collisions
• Observing many body effects on lepton pair production from low mass enhancement and flow at RHIC and LHC energies
• Hadronic Collisions in the Linked Dipole Chain Model
• Transverse spectra of hadrons at RHIC
• Transverse-Mass Spectra in Heavy-Ion Collisions at energies E_{lab} = 2--160 GeV/nucleon
• On Hydrodynamical Description of Thermal Photons
• Hydrodynamic afterburner for the CGC at RHIC
• Single photons from Pb+Pb collisions at CERN SPS, QGP vs. hadronic gas
• Charm in nuclear reactions in sqrt(s)=17 and 19 GeV
• Baryonic contributions to e+e- yields in a hydrodynamic model of Pb+Au collisions at the SPS