Constraining the density dependence of the symmetry energy in the nuclear equation of state using heavy ion beams

The density dependence of the symmetry energy in the equation of state of asymmetric nuclear matter (N/Z $>$ 1) is important for understanding the structure of systems as diverse as the atomic nuclei and neutron stars. Due to a proper lack of understanding of the basic nucleon-nucleon interaction for matters that are highly asymmetric and at non-normal nuclear density, this very important quantity has remained largely unconstrained. Recent studies using beams from the Cyclotron Institute of Texas A&M University, constraining the density dependence of the symmetry energy, is presented. A dependence of the form E$_{sym}(\rho)$ = C($\rho/\rho_{o})^{\gamma}$, where C = 31.6 MeV and $\gamma$ = 0.69, is obtained from the dynamical and statistical model analysis. Their implications to both astrophysical and nuclear physics studies are discussed.Comment: Invited talk, Proceedings of CAARI 2006, Forth Worth, Texas, Aug 20 -25, 200

Analyzing Powers for Complex Fragments Formed in the 200 MeV pol.p + Ag Reaction

This research was sponsored by the National Science Foundation Grant NSF PHY-931478

Complex Fragment Emission in the p + Ag Reaction at 160 MeV

This research was sponsored by the National Science Foundation Grant NSF PHY 87-1440

A Logarithmic, Large-Solid-Angle Detector Telescope for Nuclear Fragmentation

This research was sponsored by the National Science Foundation Grant NSF PHY-931478

Comment on Breakup Densities of Hot Nuclei

In [1,2]the observed decrease in spectral peak energies of IMFs emitted from hot nuclei was interpreted in terms of a breakup density that decreased with increasing energy. Subsequently, Raduta et al. [3] performed MMM simulations that showed decreasing spectral peaks could be obtained at constant density. In this letter we examine this apparent inconsistency.Comment: 9 pages, 2 figures, 1 tabl

Energy Dissipation and Multifragment Decay in Light-Ion-Induced Reactions

This research was sponsored by the National Science Foundation Grant NSF PHY-931478

Heavy Residue Isoscaling as a Probe of the Process of N/Z Equilibration

The isotopic and isobaric scaling behavior of the yield ratios of heavy projectile residues from the collisions of 25 MeV/nucleon 86Kr projectiles on 124Sn and 112Sn targets is investigated and shown to provide information on the process of N/Z equilibration occurring between the projectile and the target. The logarithmic slopes $\alpha$ and $\beta^{'}$ of the residue yield ratios with respect to residue neutron number N and neutron excess N--Z are obtained as a function of the atomic number Z and mass number A, respectively, whereas excitation energies are deduced from velocities. The relation of the isoscaling parameters $\alpha$ and $\beta^{'}$ with the N/Z of the primary (excited) projectile fragments is employed to gain access to the degree of N/Z equilibration prior to fragmentation as a function of excitation energy. A monotonic relation between the N/Z difference of fragmenting quasiprojectiles and their excitation energy is obtained indicating that N/Z equilibrium is approached at the highest observed excitation energies. Simulations with a deep-inelastic transfer model are in overall agreement with the isoscaling conclusions. The present residue isoscaling approach to N/Z equilibration offers an attractive tool of isospin and reaction dynamics studies in collisions involving beams of stable or rare isotopes.Comment: 15 pages, 4 figures, submitted to Phys. Lett.

Complex Fragment Emission in Coincidence with Angle-Correlated Fission Fragments in the 270 MeV 3-He + 232-Th System

This research was sponsored by the National Science Foundation Grant NSF PHY-931478

Emission of Intermediate Mass Fragments Normal to the Fission Axis in Hot Heavy Nuclei

This research was sponsored by the National Science Foundation Grant NSF PHY-931478

Search for Multifragmentation Near Threshold in the 3-He + Ag Reaction

This research was sponsored by the National Science Foundation Grant NSF PHY-931478