Dynamical and statistical bimodality in nuclear fragmentation

Abstract

The origin of bimodal behavior in the residue distribution experimentally measured in heavy ion reactions is reexamined using Boltzmann-Uehling-Uhlenbeck simulations. We suggest that, depending on the incident energy and impact parameter of the reaction, both entrance channel and exit channel effects can be at the origin of the observed behavior. Specifically, fluctuations in the reaction mechanism induced by fluctuations in the collision rate, as well as thermal bimodality directly linked to the nuclear liquid-gas phase transition are observed in our simulations. Both phenomenologies were previously proposed in the literature, but presented as incompatible and contradictory interpretations of the experimental measurements. These results indicate that heavy ion collisions at intermediate energies can be viewed as a powerful tool to study both bifurcations induced by out-of-equilibrium critical phenomena, as well as finite size precursors of thermal phase transitions.

19 pages, 8 figures

References in corpus (20)

• Thermodynamic versus statistical nonequivalence of ensembles for the mean-field Blume-Emery-Griffiths model
• Generalized canonical ensembles and ensemble equivalence
• Bimodal behavior of the heaviest fragment distribution in projectile fragmentation
• Bimodality: a possible experimental signature of the liquid-gas phase transition of nuclear matter
• Distribution of the largest fragment in the Lattice Gas Model
• Transition from participant to spectator fragmentation in Au+Au reaction between 60 AMeV and 150 AMeV
• Bimodality - a Sign of Critical Behavior in Nuclear Reactions
• Event simulations in a transport model for intermediate energy heavy ion collisions: Applications to multiplicity distributions
• Looking for bimodal distributions in multi-fragmentation reactions
• Microcanonical phase diagrams of short-range ferromagnets
• Effect of secondary decay on isoscaling: Results from the canonical thermodynamical model
• Bimodality - a general feature of heavy ion reactions
• Signals of bimodality in the fragmentation of Au quasi-projectiles
• Properties of the largest fragment in multifragmentation: a canonical thermodynamic calculation
• Statistical Ensembles with Fluctuating Extensive Quantities
• Bimodality and Coulomb effects with a canonical thermodynamic model
• Bimodalities : a survey of experimental data and models
• Generalized Gibbs ensembles for time dependent processes
• A hybrid model for studying nuclear multifragmentation around Fermi energy domain: Case for central collision of Xe on Sn
• Extended Gibbs ensembles with flow

Cited by in corpus (7)

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• Sensitivity of the evaporation residue observables to the symmetry energy
• Isospin dependent hybrid model for studying isoscaling in heavy ion collisions around the Fermi energy domain
• Distributions of the largest fragment size in multifragmentation: Traces of a phase transition
• RMF models with $\sigma$-scaled hadron masses and couplings for description of heavy-ion collisions below 2A GeV
• Transport Model Comparison Studies of Intermediate-Energy Heavy-Ion Collisions