Constraints on symmetry energy and nucleon effective mass splitting with Heavy Ion Collisions

Understand

A new version of the improved quantum molecular dynamics model has been developed to include standard Skyrme interactions.

• Four commonly used Skyrme parameter sets, SLy4, SkI2, SkM* and Gs are adopted in the transport model code to calculate the isospin diffusion observables as well as single and double ratios of transverse emitted nucleons.
• While isospin diffusion observables are sensitive to the symmetry energy term, they are not very sensitive to the nucleon effective mass splitting parameters in the interactions.
• Our calculations show that the high energy neutrons and protons and their ratios from reactions at different incident energies provide a robust observable to study the momentum dependence of the nucleon effective mass splitting.