Symmetry energy dependence of light fragment production in heavy ion collisions

We study the pre-equilibrium light cluster emission in low to intermediate energy heavy ion collisions in transport simulations as a means to obtain information about the density and momentum dependence of the nuclear symmetry potential, i.e. about the asymmetry-stiffness and the neutron-proton effective mass splitting of the symmetry energy. We find that the study of n/p and t/³He ratios as a function of the energy of the emitted particles may allow us to disentangle these two behaviors The t/³He ratios appear to carry similar information as the n/p ratios, making this a promising option for experimental investigations. More n-rich systems enhance the sensitivity to the symmetry energy, while double ratios between n-rich and n-poor systems tend to reduce it. A preliminary comparison to experimental data for the ^136,124Xe + ^124,112Sn systems is also shown