Relevance of equilibrium in multifragmentation
- GANIL (DSM-CEA/IN2P3-CNRS), Boite Postal 55027, F-14076 Caen (France)
- Department of Physics, Tohoku University, Sendai 980-8578 (Japan)
The relevance of equilibrium in a multifragmentation reaction of very central {sup 40}Ca + {sup 40}Ca collisions at 35 MeV/nucleon is investigated by using simulations of antisymmetrized molecular dynamics (AMD). Two types of ensembles are compared. One is the reaction ensemble of the states at each reaction time t in collision events simulated by AMD, and the other is the equilibrium ensemble prepared by solving the AMD equation of motion for a many-nucleon system confined in a container for a long time. The comparison of the ensembles is performed for the fragment charge distribution and the excitation energies. Our calculations show that there exists an equilibrium ensemble that well reproduces the reaction ensemble at each reaction time t for the investigated period 80{<=}t{<=}300 fm/c. However, there are some other observables that show discrepancies between the reaction and equilibrium ensembles. These may be interpreted as dynamical effects in the reaction. The usual static equilibrium at each instant is not realized since any equilibrium ensemble with the same volume as that of the reaction system cannot reproduce the fragment observables.
- OSTI ID:
- 21199506
- Journal Information:
- Physical Review. C, Nuclear Physics, Vol. 79, Issue 1; Other Information: DOI: 10.1103/PhysRevC.79.014608; (c) 2009 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2813
- Country of Publication:
- United States
- Language:
- English
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