Understanding the symmetry energy using data from the ALADIN-2000 Collaboration taken at the GSI Large Neutron Detector

Abstract

The present study deals with the extraction of the symmetry energy from heavy-ion collisions at intermediate energies. Using the isospin quantum molecular dynamical (IQMD) model, the dependence of the sum of the charge number for fragments with $Z\ge 2$ ($Z_{\text{bound}}$) on the multiplicity of neutrons ($M_n$) from the projectile spectator fragmentation of ${}^{124}$Sn and ${}^{124}$La at 600 MeV/nucleon is compared with the experimental results of the ALADIN-2000 Collaboration. The comparison suggest a soft symmetry energy. In addition, the sensitivities of the symmetry energy towards the $Z_{\text{bound}}$ dependence on proton multiplicity ($M_p$), neutron-to-proton single [$R(n/p)$] and double ratio [$R_D(n/p)$] are also examined. The $Z_{\text{bound}}$ dependence of $R(n/p)$ is found to be the most sensitive observable towards the symmetry energy. The ALADIN Collaboration should extend the results for $R(n/p)$ in the near future.

References in corpus (10)

• Symmetry energy from elliptic flow in 197Au + 197Au
• Neutron and Proton Transverse Emission Ratio Measurements and the Density Dependence of the Asymmetry Term of the Nuclear Equation of State
• Symmetry energy of dilute warm nuclear matter
• Isospin Diffusion and Equilibration for Sn+Sn collisions at E/A=35 MeV
• Isospin Dependence of Incomplete Fusion Reactions at 25 Mev/a
• Sensitivity of the transverse flow towards symmetry energy
• Effect of the symmetry energy on nuclear stopping and its relation to the production of light charged fragments
• Isospin effects in the disappearance of flow as a function of colliding geometry
• Equation of state of the neutron star matter, and the nuclear symmetry energy
• Differential isospin-fractionation in dilute asymmetric nuclear matter