Speaker
Description
The nuclear symmetry energy and its density dependence, particularly above saturation density, remain among the most significant uncertainties in the nuclear equation of state (EoS). These properties play a crucial role in both intermediate-energy heavy-ion collisions and the structure of neutron star matter. Experimental information at supra-saturation densities, however, is still limited, making such collisions a powerful probe of the symmetry energy. In this study, we investigate the $^{129,124}$Xe + $^{124,112}$Sn reactions at 100 MeV per nucleon, measured in 1998 at GSI by the INDRA–ALADIN collaboration. Directed and elliptic flow parameters extracted from the experiment are compared with transport model calculations employing the Improved Quantum Molecular Dynamics (ImQMD) framework. Two Skyrme parameterizations SkM* and Sly4, differing in their treatment of the iso-vector effective mass and neutron–proton effective mass splitting, were implemented in the simulations. By confronting experimental flow observables with theoretical predictions, we assess the sensitivity of collective dynamics to effective mass at supra-saturation densities. Our findings provide new constraints on the density dependence of the symmetry energy in the intermediate-to-high density regime, thereby contributing to a more precise determination of the nuclear EoS.