Investigation of collective radial expansion and stopping in heavy ion collisions at Fermi energies

Abstract

We present an analysis of multifragmentation events observed in central Xe+Sn reactions at Fermi energies. Performing a comparison between the predictions of the Stochastic Mean Field (SMF) transport model and experimental data, we investigate the impact of the compression-expansion dynamics on the properties of the final reaction products. We show that the amount of radial collective expansion, which characterizes the dynamical stage of the reaction, influences directly the onset of multifragmentation and the kinematic properties of multifragmentation events. For the same set of events we also undertake a shape analysis in momentum space, looking at the degree of stopping reached in the collision, as proposed in recent experimental studies. We show that full stopping is achieved for the most central collisions at Fermi energies. However, considering the same central event selection as in the experimental data, we observe a similar behavior of the stopping power with the beam energy, which can be associated with a change of the fragmentation mechanism, from statistical to prompt fragment emission.

15 pages

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Cited by in corpus (9)

• Dynamics of clusters and fragments in heavy-ion collisions
• Liquid-Gas phase transition in nuclei
• Collision dynamics at medium and relativistic energies
• Phase transition dynamics for hot nuclei
• Aspects of the momentum dependence of the equation of state and of the residual $NN$ cross section, and their effects on nuclear stopping
• Exotic break-up modes in heavy ion reactions at low energies
• Revisiting an extended-mean-field approach in heavy-ion collisions around the Fermi energy
• Production Cross Section of Neutron-Rich Calcium Isotopes in Heavy Ion Collisions
• Model independent reconstruction of impact parameter distributions for intermediate energy heavy ion collisions