Symmetry Energy Effects on Fusion Cross Sections

Abstract

We investigate the reaction path followed by Heavy Ion Collisions with exotic nuclear beams at low energies. We will focus on the interplay between reaction mechanisms, fusion vs. break-up (fast-fission, deep-inelastic), that in exotic systems is expected to be influenced by the symmetry energy term at densities around the normal value. The evolution of the system is described by a Stochastic Mean Field transport equation (SMF), where two parametrizations for the density dependence of symmetry energy (Asysoft and Asystiff) are implemented, allowing one to explore the sensitivity of the results to this ingredient of the nuclear interaction. The method described here, based on the event by event evolution of phase space quadrupole collective modes will nicely allow to extract the fusion probability at relatively early times, when the transport results are reliable. Fusion probabilities for reactions induced by 132Sn on 64,58Ni targets at 10 AMeV are evaluated. We obtain larger fusion cross sections for the more n-rich composite system, and, for a given reaction, in the Asysoft choice. Finally a collective charge equilibration mechanism (the Dynamical Dipole) is revealed in both fusion and break-up events, depending on the stiffness of the symmetry term just below saturation.

10 pages, 14 figures (revtex4)

References in corpus (22)

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• Isospin Asymmetry in Nuclei and Neutron Stars
• Reaction Dynamics with Exotic Beams
• Constraints on the density dependence of the symmetry energy
• Constraints on the symmetry energy and on neutron skins from the pygmy resonances in 68Ni and 132Sn
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• Collective Dipole Bremsstrahlung in Fusion Reactions
• Fusion of radioactive ${}^{132}$Sn with ${}^{64}$Ni
• The Dynamical Dipole Mode in Dissipative Heavy Ion Collisions
• The Dynamical Dipole Mode in Fusion Reactions with Exotic Nuclear Beams
• Stochastic Semi-Classical Description of Fusion at Near-Barrier Energies
• A new approach to solve the Boltzmann-Langevin equation for fermionic systems
• Prompt dipole radiation in fusion reactions
• Break-up mechanisms in heavy ion collisions at low energies
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Cited by in corpus (10)

• Density dependence of nuclear symmetry energy constrained by mean-field calculations
• Transport properties of isospin asymmetric nuclear matter using TDHF
• Connecting the nuclear EoS to the interplay between fusion and quasifission processes in low-energy nuclear reactions
• Sensitivity of the fusion cross section to the density dependence of the symmetry energy
• Quantal Nucleon Diffusion I: Central Collisions of Symmetric Nuclei
• Theoretical predictions of experimental observables sensitive to the symmetry energy: Results of the SMF transport model
• Pre-equilibrium effects in charge-asymmetric low-energy reactions
• Exotic break-up modes in heavy ion reactions at low energies
• Above-barrier heavy-ion fusion cross-sections using the relativistic mean-field approach: case of spherical colliding nuclei
• Probing the sensitivity of the total nucleus-nucleus reaction cross section at intermediate energies to medium effects and isospin asymmetries