Microscopic models and effective equation of state in nuclear collisions at FAIR energies

Abstract

Two microscopic models, UrQMD and QGSM, were employed to study the formation of locally equilibrated hot and dense nuclear matter in heavy-ion collisions at energies from 11.6 AGeV to 160 AGeV. Analysis was performed for the fixed central cubic cell of volume V = 125 fm**3 and for the expanding cell which followed the growth of the central area with uniformly distributed energy. To decide whether or not the equilibrium was reached, results of the microscopic calculations were compared to that of the statistical thermal model. Both dynamical models indicate that the state of kinetic, thermal and chemical equilibrium is nearly approached at any bombarding energy after a certain relaxation period. The higher the energy, the shorter the relaxation time. Equation of state has a simple linear dependence P = a(sqrt{s})*e, where a = c_s**2 is the sound velocity squared. It varies from 0.12 \pm 0.01 at E_{lab} = 11.6 AGeV to 0.145 \pm 0.005 at E_{lab} = 160 AGeV. Change of the slope in a(sqrt{s}) behavior occurs at E_{lab} = 40 AGeV and can be assigned to the transition from baryon-rich to meson-dominated matter. The phase diagrams in the T - mu_B plane show the presence of kinks along the lines of constant entropy per baryon. These kinks are linked to the inelastic (i.e. chemical) freeze-out in the system.

14 pages, REVTEX

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Cited by in corpus (29)

• Monte-Carlo generator of heavy ion collisions DCM-SMM
• Examination of directed flow as a signature of the softest point of the equation of state in QCD matter
• Different space-time freeze-out picture -- an explanation of different $\Lambda$ and $\bar{\Lambda }$ polarization?
• Hot and dense hadronic matter in an effective mean field approach
• D-meson propagation in hot dense matter
• Deviations of the Energy-Momentum Tensor from Equilibrium in the Initial State for Hydrodynamics from Transport Approaches
• Effects of a phase transition on HBT correlations in an integrated Boltzmann+Hydrodynamics approach
• Isentropic thermodynamics in the PNJL model
• The high-density equation of state in heavy-ion collisions: Constraints from proton flow
• Modeling the diffusive dynamics of critical fluctuations near the QCD critical point
• Open bottom states and the anti-B meson propagation in hadronic matter
• Nonextensive statistical effects in the hadron to quark-gluon phase transition
• Dilepton production in heavy-ion collisions with in-medium spectral functions of vector mesons
• Kaon and Pion Production in Central Au+Au Collisions at \sqrt{s_{NN}}=62.4 GeV
• Charm and Bottom Hadrons in Hot Hadronic Matter
• Equation of state at FAIR energies and the role of resonances
• Bulk Properties of the Matter Produced at Energies of the Beam Energy Scan Program
• Global $\Lambda$ polarization in heavy-ion collisions at energies 2.4--7.7 GeV: Effect of Meson-Field Interaction
• Shear viscosity in microscopic calculations of A+A collisions at energies of Nuclotron-based Ion Collider fAcility (NICA)
• Estimates of the baryon densities attainable in heavy-ion collisions from the beam energy scan program
• Equilibration and baryon densities attainable in relativistic heavy-ion collisions
• Chiral Hadronic Mean Field Model including Quark Degrees of Freedom
• Charmonium suppression in a baryon rich quark-gluon plasma
• Ultra fast, event-by-event heavy-ion simulations for next generation experiments
• D-meson diffusion in hadronic matter
• Early thermalization and shear viscosity to entropy ratio in heavy-ion collisions at energies of BES, FAIR and NICA
• Optimal collision-energy range for realizing macroscopic high-baryon-density matter
• A Chiral Mean-Field Equation-of-State in UrQMD: Effects on the Heavy Ion Compression Stage
• Strangeness production at finite temperature and baryon density in an effective relativistic mean field model