Nuclear matter properties in fragmentation reactions

Nuclear multifragmentation is closely related to the properties of nuclear matter. In particular, the possibility of strong cluster correlations is explored based on the antisymmetrized molecular dynamics calculations. We introduce the two-nucleon collision process to the final states in which the scattered nucleons may form clusters (such as deuterons, tritons and α particles). This cluster correlation has strong impacts on the whole collision dynamics. The multifragmentation data at 50 MeV/nucleon are well reproduced with this strong cluster correlation if pairs of clusters with small relative velocities are assumed to form light nuclei. Effects of the density dependence of symmetry energy are discussed by analyzing the compression-expansion dynamics and the emission of nucleons, clusters and fragment nuclei.