Evolution of the symmetry energy of hot neutron-rich matter formed in heavy-ion reactions

Abstract

It is shown that the experimentally observed decrease of the nuclear symmetry energy with the increasing centrality or the excitation energy in isotopic scaling analyses of heavy-ion reactions can be well understood analytically within a degenerate Fermi gas model. The evolution of the symmetry energy is found to be mainly due to the variation in the freeze-out density rather than temperature. The isoscaling analyses are useful for probing the interaction part of the nuclear symmetry energy, provided that both the freeze-out temperature and density of the fragments can be inferred simultaneously from the experiments.

arXiv comment6 pages, 2 figures. Title changed little, comments on extracting the symmetry energy from the isoscaling phenomenon are added. Revised version to appear in PRC

References in corpus (36)

• Neutron Star Structure and the Equation of State
• The Physics of Neutron Stars
• Isospin Asymmetry in Nuclei and Neutron Stars
• A Radio Pulsar Spinning at 716 Hz
• Reaction Dynamics with Exotic Beams
• Neutron-Rich Nuclei in Heaven and Earth
• Isospin Physics in Heavy-Ion Collisions at Intermediate Energies
• Determination of the stiffness of the nuclear symmetry energy from isospin diffusion
• Isotopic Scaling in Nuclear Reactions
• Nuclear Matter and its Role in Supernovae, Neutron Stars and Compact Object Binary Mergers
• Nuclear matter symmetry energy and the neutron skin thickness of heavy nuclei
• Nucleon-nucleon cross sections in neutron-rich matter and isospin transport in heavy-ion reactions at intermediate energies
• Momentum dependence of symmetry potential in asymmetric nuclear matter for transport model calculations
• Cluster Formation and The Virial Equation of State of Low-Density Nuclear Matter
• Neutron-Proton Differential Flow as a Probe of Isospin-Dependence of Nuclear Equation of State
• Effects of momentum-dependent symmetry potential on heavy-ion collisions induced by neutron-rich nuclei
• Isospin fractionation and isoscaling in dynamical nuclear collisions
• Isoscaling in Light-Ion Induced Reactions and its Statistical Interpretation
• Presupernova collapse models with improved weak-interaction rates
• Isotopic Scaling and the Symmetry Energy in Spectator Fragmentation
• Imaging of Sources in Heavy-Ion Reactions
• Isospin Diffusion in Heavy-Ion Collisions and the Neutron Skin Thickness of Lead
• Isoscaling of projectile-like fragments
• Symmetry energy for fragmentation in dynamical nuclear collisions
• Symmetry energy and the isospin dependent equation of state
• Heavy Residue Isoscaling as a Probe of the Symmetry Energy of Hot Fragments
• The Liquid-Gas Phase Transitions in a Multicomponent Nuclear System with Coulomb and Surface Effects
• Symmetry energy and the isoscaling properties of the fragments produced in ${}^{40}$Ar, ${}^{40}$Ca + ${}^{58}$Fe, ${}^{58}$Ni reactions at 25 $-$ 53 MeV/nucleon
• Hot Nuclear Matter Equation of State with a Three-body Force
• Dynamical aspects of isoscaling
• Isoscaling behavior in the Fission Dynamics
• On the temperature dependence of the symmetry energy
• Temperature dependence of the nuclear symmetry energy
• Temperature dependence of single-particle properties in nuclear matter
• Nuclear Incompressibility in Asymmetric Systems at Finite Temperature and Entropy
• Extracting particle freeze-out phase-space densities and entropies from sources imaged in heavy-ion reactions

Cited by in corpus (29)

• Recent Progress and New Challenges in Isospin Physics with Heavy-Ion Reactions
• Density dependence of the symmetry energy and the nuclear equation of state: A Dynamical and Statistical model perspective
• Isospin dependent multifragmentation of relativistic projectiles
• Temperature effects on the nuclear symmetry energy and symmetry free energy with an isospin and momentum dependent interaction
• Probing isospin- and momentum-dependent nuclear effective interactions in neutron-rich matter
• Effects of isospin and momentum dependent interactions on thermal properties of asymmetric nuclear matter
• Thermal effects on nuclear symmetry energy with a momentum-dependent effective interaction
• Isoscaling as a measure of Symmetry Energy in the Lattice Gas Model
• Temperature dependence of the symmetry energy and neutron skins in Ni, Sn, and Pb isotopic chains
• Temperature and momentum dependence of single-particle properties in hot asymmetric nuclear matter
• Isospin dependent thermodynamics of fragmentation
• Effect of splitting of the neutron and proton effective mass on nuclear symmetry energy at finite temperature
• N/Z Dependence of Projectile Fragmentation
• Nuclear symmetry energy and the role of three-body forces
• Isospin effect in the statistical sequential decay
• Isoscaling and the nuclear EOS
• Symmetry energy of fragments produced in multifragmentation
• Temperature dependence of the volume and surface contributions to the nuclear symmetry energy within the coherent density fluctuation model
• Chemical Property of Colliding Sources in 124,136Xe and 112,124Sn Induced Collisions in Isobaric Ratio Difference and Isoscaling Methods
• Density dependence of symmetry free energy of hot nuclei
• Isoscaling, Symmetry Energy and Thermodynamic Models
• Temperature effects in the nuclear isoscaling
• Heavy-ion Collisions: Direct and indirect probes of the density and temperature dependence of Esym
• The role of bulk energy in nuclear multifragmentation
• Density dependence of the "symmetry energy" in the lattice gas model
• Isoscaling in statistical fragment emission in an extended compound nucleus model
• Symmetry energy from fragment observables in the canonical thermodynamic model
• Sensitive dependence of isotope and isobar distribution of limiting temperatures on symmetry energy
• Isobar correlations bearing information on the properties of hot disassembling nuclear sources