Speaker
Description
The statistical approaches were previously successfully applied
for the description of the disintegration of excited nuclear sources.
Such single sources in equilibrium with the temperature around
6-8 MeV (also with smaller temperatures) can be produced both
from spectator residues in peripheral collisions of nuclei and
after the fusion of nuclei in central collisions at Fermi energy.
We generalize this approach [1,2] and demonstrate that the new
conception of local equilibrium can be used to explain the
fragment formation in quickly expanding nuclear matter under
very high excitation energy. In this case we consider the matter
subdivided into several excited clusters. For the first time our
approach is able to describe consistently the FOPI experimental
data measured in central collisions, in particular, yields and
kinetic energies of nuclei, and the modification of the nuclear
isotope yields with increasing the beam energy. In peripheral
collisions of Fermi energy we are able to explain [3] the
projectile-like and neck-like fragment emission (in FAZIA
experiment) by separating two local sources in the reaction.
Relation to the symmetry energy during the statistical fragment
formation is discussed. We have obtained the limitation on
the temperature of such local sources which determines the
statistical nucleation process.
[1] A.S. Botvina, et al., Phys. Rev. C103, 064602 (2021).
[2] A.S. Botvina, et al., Phys. Rev. C106, 014607 (2022).
[3] R. Ogul, et al., Phys. Rev. C107, 054606 (2023).
