Probing Mechanical and Chemical Instabilities in Neutron-Rich Matter

Abstract

The isospin-dependence of mechanical and chemical instabilities is investigated within a thermal and nuclear transport model using a Skyrme-type phenomenological equation of state for neutron-rich matter. Respective roles of the nuclear mean field and the 2-body stochastic scattering on the evolution of density and isospin fluctuations in either mechanically or chemically unstable regions of neutron-rich matter are investigated. It is found that the mean field dominates overwhelmingly the fast growth of both fluctuations, while the 2-body scattering influences significantly the later growth of the isospin fluctuation only. The magnitude of both fluctuations decreases with the increasing isospin asymmetry because of the larger reduction of the attractive isoscalar mean field by the stronger repuslive neutron symmetry potential in the more neutron-rich matter. Moreover, it is shown that the isospin fractionation happens later, but grows faster in the more neutron-rich matter. Implications of these results to current experiments exploring properties of neutron-rich matter are discussed.

18 pages & 15 figures, Nuclear Physics A (2001) in press

References in corpus (2)

• Isotopic Scaling in Nuclear Reactions
• Spinodal decomposition of low-density asymmetric nuclear matter

Cited by in corpus (15)

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• Liquid-Gas phase transition in nuclei
• Instabilities in asymmetric nuclear matter
• Effects of isospin and momentum dependent interactions on thermal properties of asymmetric nuclear matter
• Effects of isospin and momentum dependent interactions on liquid-gas phase transition in hot asymmetric nuclear matter
• Warm asymmetric matter in the Quark Meson Coupling Model
• Dynamical properties of nuclear and stellar matter and the symmetry energy
• Shear viscosity of neutron-rich nucleonic matter near its liquid-gas phase transition
• Transition density and pressure in hot neutron stars
• Directed and elliptic flows of protons and deuterons in HADES Au+Au collisions at $\sqrt{s_{\mathrm{NN}}}=2.4$ GeV
• Core-crust transition properties of neutron stars within systematically varied extended relativistic mean-field model
• Strong correlation of the neutron star core-crust transition density with the $\sigma$-meson mass via vacuum polarization
• Probing the high-density behavior of nuclear symmetry energy with high-energy radioactive beams
• Isospin and momentum dependence of liquid-gas phase transition in hot asymmetric nuclear matter