Timescales of quantum equilibration, dissipation and fluctuation in nuclear collisions

• URL: http://arxiv.org/abs/2005.04357v1
• Date: Sat, 9 May 2020 02:59:10 GMT
• Title: Timescales of quantum equilibration, dissipation and fluctuation in nuclear collisions
• Authors: C. Simenel, K. Godbey, A.S. Umar
• Abstract summary: equilibration processes in quantum systems are investigated using fully microscopic approaches. The timescale for full mass equilibration ($sim2times10-20$s) is found to be much larger than timescales for neutron-to-proton equilibration. Fluctuations of mass numbers in the fragments and correlations between their neutron and proton numbers build up within only a few $10-21$s.
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: Understanding the dynamics of equilibration processes in quantum systems as well as their interplay with dissipation and fluctuation is a major challenge in quantum many-body theory. The timescales of such processes are investigated in collisions of atomic nuclei using fully microscopic approaches. Results from time-dependent Hartree-Fock (TDHF) and time-dependent random-phase approximation (TDRPA) calculations are compared for 13 systems over a broad range of energies. The timescale for full mass equilibration ($\sim2\times10^{-20}$s) is found to be much larger than timescales for neutron-to-proton equilibration, kinetic energy and angular momentum dissipations which are on the order of $10^{-21}$s. Fluctuations of mass numbers in the fragments and correlations between their neutron and proton numbers build up within only a few $10^{-21}$s. This indicates that dissipation is basically not impacted by mass equilibration, but is mostly driven by the exchange of nucleons between the fragments.

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