Isospin Dynamics in Heavy Ion Collisions: from Coulomb Barrier to Quark Gluon Plasma

Abstract

Heavy Ion Collisions (HIC) represent a unique tool to probe the in-medium nuclear interaction in regions away from saturation. In this report we present a selection of new reaction observables in dissipative collisions particularly sensitive to the symmetry term of the nuclear Equation of State (Iso-EoS). We will first discuss the Isospin Equilibration Dynamics. At low energies this manifests via the recently observed Dynamical Dipole Radiation, due to a collective neutron-proton oscillation with the symmetry term acting as a restoring force. At higher beam energies Iso-EoS effects will be seen in Imbalance Ratio Measurements, in particular from the correlations with the total kinetic energy loss. For fragmentation reactions in central events we suggest to look at the coupling between isospin distillation and radial flow. In Neck Fragmentation reactions important $Iso-EoS$ information can be obtained from the correlation between isospin content and alignement. The high density symmetry term can be probed from isospin effects on heavy ion reactions at relativistic energies (few AGeV range). Rather isospin sensitive observables are proposed from nucleon/cluster emissions, collective flows and meson production. The possibility to shed light on the controversial neutron/proton effective mass splitting in asymmetric matter is also suggested. A large symmetry repulsion at high baryon density will also lead to an "earlier" hadron-deconfinement transition in n-rich matter. A suitable treatment of the isovector interaction in the partonic EoS appears very relevant.

18 pages, 12 figures, lecture at the 2008 Erice School on Nuclear Physics, to appear in Progress in Particle and Nuclear Physics

References in corpus (7)

• Isotopic dependence of the giant monopole resonance in the even-A ^{112-124}Sn isotopes and the asymmetry term in nuclear incompressibility
• Isospin effects on sub-threshold kaon production at intermediate energies
• The Dynamical Dipole Mode in Fusion Reactions with Exotic Nuclear Beams
• Isospin Distillation with Radial Flow: a Test of the Nuclear Symmetry Energy
• Prompt dipole radiation in fusion reactions
• Phase Transition of Finite Size Quark Droplets with Isospin Chemical Potential in the Nanbu--Jona-Lasinio Model
• Hierarchy in mid-rapidity fragmentation: mass, isospin, velocity correlations

Cited by in corpus (18)

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• Symmetry Energy Effects on the Mixed Hadron-Quark Phase at High Baryon Density
• Probing the nuclear equation of state in heavy-ion collisions at Fermi energy in isospin-sensitive exclusive experiments
• Hadron-quark phase transition in asymmetric matter with dynamical quark masses
• Isospin effects and symmetry energy studies with INDRA
• Phase transitions of hadronic to quark matter at finite T and μ_B
• Phase transition of strongly interacting matter with a chemical potential dependent Polyakov loop potential
• Low-momentum interactions with Brown-Rho-Ericson scalings and the density dependence of the nuclear symmetry energy
• The High-Density Symmetry Energy in Heavy Ion Collisions
• Probing the momentum dependence of medium modifications of the nucleon-nucleon elastic cross sections
• Symmetry energy from fragment observables in the canonical thermodynamic model
• Probing the hadron-quark mixed phase at high isospin and baryon density - Sensitive observables
• Probing the symmetry energy at high baryon density with heavy ion collisions
• Isentropic thermodynamics across the hadron-quark mixed phase in a two-phase model with a PNJL quark description