Isospin effect in peripheral heavy-ion collisions at Fermi energies

Abstract

Within the framework of the Lanzhou quantum molecular dynamics (LQMD) transport model, the isospin effect in peripheral heavy-ion collisions has been investigated thoroughly. A coalescence approach is used for recognizing the primary fragments formed in nucleus-nucleus collisions. The secondary decay process of the fragments is described by the statistical code, GEMINI. Production mechanism and isospin effect of the projectile-like and target-like fragments are analyzed with the combined approach. It is found that the isospin migration from the high-isospin density to the low-density matter takes place in the neutron-rich nuclear reactions, i.e., ${}^{48}$Ca+${}^{208}$Pb, ${}^{86}$Kr+${}^{48}$Ca/${}^{208}$Pb/${}^{124}$Sn, ${}^{136}$Xe+${}^{208}$Pb, ${}^{124}$Sn+${}^{124}$Sn and ${}^{136}$Xe+${}^{136}$Xe. A hard symmetry energy is available for creating the neutron-rich fragments, in particular in the medium-mass region. The isospin effect of the neutron to proton (n/p) ratio of the complex fragments is reduced once including the secondary decay process. However, a soft symmetry energy enhances the n/p ratio of the light particles, in particular at the kinetic energies above 15 MeV/nucleon.

arXiv comment8 pages, 8 figures

References in corpus (21)

• Recent Progress and New Challenges in Isospin Physics with Heavy-Ion Reactions
• Reaction Dynamics with Exotic Beams
• Determination of the stiffness of the nuclear symmetry energy from isospin diffusion
• Comparison of heavy-ion transport simulations: Collision integral in a box
• Application of Information Theory in Nuclear Liquid Gas Phase Transition
• Momentum dependence of the symmetry potential and its influence on nuclear reactions
• Isospin Diffusion and Equilibration for Sn+Sn collisions at E/A=35 MeV
• Correlations between emission timescale of fragments and isospin dynamics in ${}^{124}$Sn+${}^{64}$Ni and ${}^{112}$Sn+${}^{58}$Ni reactions at 35 AMeV
• Production of heavy and superheavy nuclei in massive fusion reactions
• Nuclear dynamics and particle production near threshold energies in heavy-ion collisions
• Dynamical approach to heavy-ion induced fission using actinide target nuclei at energies around the Coulomb barrier
• Probing the density dependence of the symmetry potential with peripheral heavy-ion collisions
• How tightly is nuclear symmetry energy constrained by unitary Fermi gas?
• Experimental effects on dynamics and thermodynamics in nuclear reactions on the symmetry energy as seen by the CHIMERA 4$\pi$ detector
• The Influence of in-medium NN cross-sections, symmetry potential and impact parameter on the isospin observables
• Effective Nucleon Masses from Heavy Ion Collisions
• In-medium and isospin effects on particle production near threshold energies in heavy-ion collisions
• Microscopic dynamics simulations of multi-nucleon transfer in ${}^{86}$Kr+${}^{64}$Ni at 25 MeV/nucleon
• Isospin dynamics on neck fragmentation in isotopic nuclear reactions
• Particle production in antiproton induced nuclear reactions
• Nuclear in-medium effects on $\eta$ dynamics in proton-nucleus collisions