107 research outputs found
Probing the symmetry energy and the degree of isospin equilibrium
The rapidity dependence of the single- and double- neutron to proton ratios
of nucleon emission from isospin-asymmetric but mass-symmetric reactions Zr+Ru
and Ru+Zr at energy range A MeV and impact parameter range
fm is investigated. The reaction system with isospin-asymmetry and
mass-symmetry has the advantage of simultaneously showing up the dependence on
the symmetry energy and the degree of the isospin equilibrium. We find that the
beam energy- and the impact parameter dependence of the slope parameter of the
double neutron to proton ratio () as function of rapidity are quite
sensitive to the density dependence of symmetry energy, especially at energies
A MeV and reduced impact parameters around 0.5. Here the symmetry
energy effect on the is enhanced, as compared to the single neutron to
proton ratio. The degree of the equilibrium with respect to isospin (isospin
mixing) in terms of the is addressed and its dependence on the symmetry
energy is also discussed.Comment: 10 pages, 2 figure
In-medium NN cross sections determined from stopping and collective flow in intermediate-energy heavy-ion collisions
In-medium nucleon-nucleon scattering cross sections are explored by comparing
results of quantum molecular dynamics simulations to data on stopping and on
elliptic and directed flow in intermediate-energy heavy-ion collisions. The
comparison points to in-medium cross sections which are suppressed at low
energies but not at higher energies. Positive correlations are found between
the degree of stopping and the magnitudes of elliptic and directed flows.Comment: 11 pages, 4 figures, to be published on PR
Mass and Isotope Dependence of Limiting Temperatures for Hot Nuclei
The mass and isotope dependence of limiting temperatures for hot nuclei are
investigated. The predicted mass dependence of limiting temperatures is in good
agreement with data derived from the caloric curve data. The predicted isotope
distribution of limiting temperatures appears to be a parabolic shape and its
centroid is not located at the isotope on the -stability line(T=0) but
at neutron-rich side. Our study shows that the mass and isotope dependence of
limiting temperatures depend on the interaction and the form of surface tension
and its isopin dependence sensitively.Comment: 14 pages,11 figure
Re-visit the N/Z ratio of free nucleons from collisions of neutron-rich nuclei as a probe of EoS of asymmetric nuclear matter
The N/Z ratio of free nucleons from collisions of neutron-rich nuclei as a function of their momentum is studied by means of Isospin dependent Quantum Molecular Dynamics. We find that this ratio is not only sensitive to the form of the density dependence of the symmetry potential energy but also its strength determined by the symmetry energy coe cient. The uncertainties about the symmetry energy coe cient influence the accuracy of probing the density dependence of the symmetry energy by means of the N/Z ratio of free nucleons of neutron-rich nuclei
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