A novel determination of density, temperature and symmetry energy for nuclear multi-fragmentation through primary fragment yield reconstruction

For thefirst time primary hot isotope distributions are experimentally reconstructed in intermediate heavy-ion collisions and used with antisymmetrized molecular dynamics (AMD) calculations to determine density, temperature, and symmetry energy coefficient in a self-consistent manner. A kinematical focusing method is employed to reconstruct the primary hot fragment-yield distributions for multifragmentation events observed in the reaction system Zn-64 + Sn-112 at 40 MeV/nucleon. The reconstructed yield distributions are in good agreement with the primary isotope distributions of AMD simulations. The experimentally extracted values of the symmetry energy coefficient relative to the temperature, a(sym)/T, are compared with those of the AMD simulations with different density dependence of the symmetry energy term. The calculated a(sym)/T values change according to the different interactions. By comparison of the experimental values of a(sym)/T with those of calculations, the density of the source at fragment formation was determined to be rho/rho(0) = (0.63 +/- 0.03). Using this density, the symmetry energy coefficient and the temperature are determined in a self-consistent manner as a(sym) = (24.7 +/- 1.9) MeV and T = (4.9 +/- 0.2) MeV.