Constraints on the density dependence of the symmetry energy
  Collisions involving 112Sn and 124Sn nuclei have been simulated with the improved Quantum Molecular Dynamics transport model. The results of the calculations reproduce isospin diffusion data from two different observables and the ratios of neutron and proton spectra. By comparing these data to calculations performed over a range of symmetry energies at saturation density and different representations of the density dependence of the symmetry energy, constraints on the density dependence of the symmetry energy at sub-normal density are obtained. Results from present work are compared to constraints put forward in other recent analysis. 
M.B.Tsang, Yingxun Zhang, P.Danielewicz, M.Famiano, Zhuxia Li,   W.G.Lynch, A.W.Steiner