  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.
