Article

The Isospin Dependence Of The Nuclear Equation Of State Near The Critical Point

Physical Review C (Impact Factor: 3.88). 02/2010; DOI: 10.1103/PhysRevC.81.044618
Source: arXiv

ABSTRACT We discuss experimental evidence for a nuclear phase transition driven by the different concentration of neutrons to protons. Different ratios of the neutron to proton concentrations lead to different critical points for the phase transition. This is analogous to the phase transitions occurring in 4He-3He liquid mixtures. We present experimental results which reveal the N/A (or Z/A) dependence of the phase transition and discuss possible implications of these observations in terms of the Landau Free Energy description of critical phenomena. Comment: 14 pages, 18 figures

0 Bookmarks
 · 
77 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We address the role of Coulomb interaction in the determination of densities and temperatures of hot sources produced in heavy ion collisions. Such quantities can be obtained from the quadrupole momentum and multiplicity fluctuations of the emitted light particles. In this paper we modify the method by taking explicitly into account Coulomb corrections. The classical and quantum limits for fermions are discussed. In the classical case we find that the temperatures determined from 3H and 3He, after the Coulomb correction, are very similar to those obtained from neutrons within the constrained molecular dynamics approach. In the quantum case, the proton temperature becomes very similar to neutron's, while densities are not sensitive to the Coulomb corrections.
    Journal of Physics G Nuclear and Particle Physics 03/2014; 41(5):055109. · 2.84 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: For the first time primary hot isotope distributions are experimentally reconstructed in intermediate heavy ion collisions and used with antisymmetrized molecular dynamics (AMD) calculations to determine density, temperature and symmetry energy coefficient in a self-consistent manner. A kinematical focusing method is employed to reconstruct the primary hot fragment yield distributions for multifragmentation events observed in the reaction system $^{64}$Zn + $^{112}$Sn at 40 MeV/nucleon.The reconstructed yield distributions are in good agreement with the primary isotope distributions of AMD simulations. The experimentally extracted values of the symmetry energy coefficient relative to the temperature, $a_{sym}/T$, are compared with those of the AMD simulations with different density dependence of the symmetry energy term.The calculated $a_{sym}/T$ values changes according to the different interactions. By comparison of the experimental values of $a_{sym}/T$ with those of alculations, the density of the source at fragment formation was determined to be $\rho /\rho_{0} = (0.63 \pm 0.03 )$. Using this density, the symmetry energy coefficient and the temperature are determined in a self-consistent manner as $a_{sym} = (23.5 \pm 1.5) MeV$ and $T=(5.1 \pm 0.1)$ MeV.
    Physical Review C 02/2014; 89(2). · 3.88 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: With the aid of our recent experiment, the fragmentation of 56Fe at 471 A MeV interacting with C and Al targets has been systematically studied by the improved quantum molecular dynamics model together with the statistical GEMINI model. The fragment distributions in heavy-ion collisions at intermediate energies can be well reproduced by using this combination of the two models. It is found that the odd–even effect of the partial cross sections observed in experiments appears in the de-excitation process of the excited primary fragments as a result of pairing effect and is mainly formed in the grazing collisions. The peaked angular distributions of primary ions and their fragments are dominantly due to the heavier fragments produced in the grazing collisions and reveal the nonequilibrium property of collisions and the memory effects of outgoing fragments on the entrance channel.
    Nuclear Physics A 12/2013; 920:1–19. · 2.50 Impact Factor

Full-text (2 Sources)

Download
37 Downloads
Available from
May 22, 2014