Matter Evolution and Soft Physics in A + A Collisions

The principal problems of the matter evolution in hydrodynamic picture of A+A collisions are considered. They concern the process of freezeout, possible duality in the hydrodynamic and kinetic descriptions, and formation of the initial conditions at pre-thermal partonic stage, in particular, developing of initial transverse velocities and angular momentum. Also time evolution of the momentum spectra, Bose-Einstein correlation functions and averaged phase-space densities (APSD) are analyzed within hydrodynamic and kinetic models. The results shed light on the behavior of the observables, in particular, the interferometry volumes and APSD in A+A collisions at di rent energies and for di rent nuclei. The new class of freeze-out parameterizations, accounting for continuous in time particle emission, is considered and their hydrodynamical realization is discussed. (author)