S. N. Soisson

Symmetry energy and the isospin dependent equation of state

We show that the large sequential decay corrections obtained by Ono {\it et al} [nucl-ex/0507018], is in contradiction with both the other dynamical and statistical model calculations carried out for the same systems and energy. On the other hand, the conclusion of Shetty {\it {et al.}}

Measuring the temperature of hot nuclear fragments

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Symmetry energy and the isoscaling properties of the fragments produced in Ar 40 , Ca 40 + Fe 58 , Ni 58 reactions at 25, 33, 45, and 53 MeV/nucleon

Phys. Rev. C 70, 011601R (2004)

Isoscaling of fragments with Z = 1 − 17 from reconstructed quasiprojectiles

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Quantum suppression of fluctuations and temperatures of reconstructed A ∼ 30 quasi-projectiles

, that the experimental data favors Gogny

Nuclear expansion and symmetry energy of hot nuclei

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Recent Updates to the FAUST Array

AS interaction (obtained assuming a significantly smaller sequential decay effects), is consistent with several other independent studies.

Multifragmentation of reconstructed quasi-projectiles in the mass region A ∼ 30

Abstract A new thermometer based on fragment momentum fluctuations is presented. This thermometer exhibited residual contamination from the collective motion of the fragments along the beam axis. For this reason, the transverse direction has been explored. Additionally, a mass dependence was observed for this thermometer. This mass dependence may be the result of the Fermi momentum of nucleons or the different properties of the fragments (binding energy, spin, etc.) which might be more sensitive to different densities and temperatures of the exploding fragments. We expect some of these aspects to be smaller for protons (and/or neutrons); consequently, the proton transverse momentum fluctuations were used to investigate the temperature dependence of the source.

Intermediate Mass Fragment Flow as a Probe to the Nuclear Equation of State

The symmetry energy and the isoscaling properties of the fragments produced in the multifragmentation of {sup 40}Ar, {sup 40}Ca+{sup 58}Fe, {sup 58}Ni reactions at 25, 33, 45, and 53 MeV/nucleon were investigated within the framework of statistical multifragmentation model. The isoscaling parameters {alpha}, from the primary (hot) and secondary (cold) fragment yield distributions, were studied as a function of excitation energy, isospin (neutron-to-proton asymmetry), and fragment symmetry energy. It is observed that the isoscaling parameter {alpha} decreases with increasing excitation energy and decreasing symmetry energy. The parameter {alpha} is also observed to increase with increasing difference in the isospin of the fragmenting system. The sequential decay of the primary fragments into secondary fragments, when studied as a function of excitation energy and isospin of the fragmenting system, show very little influence on the isoscaling parameter. The symmetry energy, however, has a strong influence on the isospin properties of the hot fragments. The experimentally observed scaling parameters can be explained by symmetry energy that is significantly lower than that for the ground-state nuclei near saturation density. The results indicate that the properties of hot nuclei at excitation energies, densities, and isospin away from the normal ground-state nuclei could be significantly different.

Investigation of critical behaviour from nuclear fragment yield ratios

In heavy-ion collisions, isoscaling provides a method for studying the evolution of nuclear symmetry energy as a function of excitation energy. One challenge in using isoscaling is to accurately determine the neutron-to-proton ratio (N/Z) of the fragmenting source. Isoscaling results are presented for the reactions of {sup 86,78}Kr+{sup 64,58}Ni at 35 MeV/nucleon taken on the NIMROD-ISiS array at Texas A and M University. The N/Z of the source was calculated from the isotopically identified fragments and experimentally measured neutrons emitted from reconstructed quasiprojectiles. These data exhibit isoscaling for elements with Z=1-17 over a broad range of isotopes. The isoscaling parameter {alpha} is shown to increase with increasing difference in the neutron composition ({delta}) of the compared sources. For a selected {delta}, the ratio {alpha}/{delta} is also shown to decrease with increasing excitation energy. This may reflect a corresponding decrease in the nuclear symmetry energy.