Density fluctuations in intermediate-energy heavy-ion collisions

Within the framework of the isospin-dependent quantum molecular dynamics model, we simulate 129 Xe + 119 Sn collisions in an incident energy range of 20 to 190 MeV/nucleon and discuss the liquid-gas phase transition with density fluctuations. For comparison, we also extract the effective Fisher parameter τ eff , multiplicity of intermediate-mass fragments (IMFs), and information entropy. It is found that the Fisher parameter and maximum information entropy of collisions have peak values at E beam = 50 –80 MeV/nucleon. In addition, the maximum multiplicity of IMFs has a plateau around 70 MeV/nucleon. For higher-order density moments in a larger central region of [ - 5 , 5 ] 3 fm 3 in the collision system, a maximum plateau also appears as function of beam energy at energies exceeding 70 MeV/nucleon. These observables, which are consistent with each other, indicate a liquid-gas phase transition around 70 MeV/nucleon for the 129 Xe + 119 Sn system.