  Central nucleus-nucleus collisions produce many new baryons and the nuclear
clusters can be formed from these species. The phenomenological coalescence
models were sufficiently good for description of light nuclei yields in a very
broad range of collision energies. We demonstrate that in reality the
coalescence process can be considered as 1) the formation of primary diluted
excited baryon clusters and 2) their following statistical decay leading to the
final cold fragment production. We argue that the formation of such excited
systems from the interacting baryons is a natural consequence of the nuclear
interaction at subnuclear densities resulting in the nuclear liquid-gas type
phase transition in finite systems. In this way one can provide a consistent
interpretation of the experimental fragment yields (FOPI data) including the
important collision energy dependence in relativistic ion reactions. We
investigate the regularities of this new kind of fragment production, for
example, their yield, isospin, and kinetic energy characteristics. A
generalization of such a clusterization mechanism for hypernuclear matter is
suggested. The isotope yields and particle correlations should be adequate for
studying these phenomena.
