Connection between the Largest Lyapunov Exponent, Density Fluctuation and Multifragmentation in Excited Nuclear Systems

Within a quantum molecular dynamics model we calculate the largest Lyapunov exponent (LLE), density fluctuation and mass distribution of fragments for a series of nuclear systems at different initial temperatures. It is found that the LLE peaks at the temperature (”critical temperature”) where the density fluctuation reaches a maximal value and the mass distribution of fragments is best fitted by the Fisher’s power law from which the critical exponents for mass and charge distribution are obtained. The time-dependent behavior of the LLE and density fluctuation is studied. We find that the time scale of the density fluctuation is much longer than the inverse LLE, which indicates ∗Supported by National Natural Science Foundation of China under Grant Nos. 10175093, 10175089 10235030, 10235020 and Science Foundation of Chinese Nuclear Industry and Major State Basic Research Development Program under Contract No. G20000774. E-Mail: [email protected]