Description of the Spectra of Cumulative Protons, Pions, and Photons in Collisions of Heavy Intermediate-Energy Ions Based on a Nonequilibrium Hydrodynamic Approach

A nonequilibrium hydrodynamic approach is developed to describe the emission of protons, pions, and photons produced in collisions of heavy intermediate-energy ions, and the correction for the microcanonical distribution is applied, and the fragmentation process contribution is included. The ITEP experimental data on the emission of protons, pions, and photons in collisions of C-12 nuclei with a beryllium target at energies of 2.0 and 3.2 GeV/nucleon are considered. It is demonstrated that these data can be uniformly described within the framework of a nonequilibrium hydrodynamic model for the high-energy cumulative region of a proton spectrum with consideration for the contribution from the fragmentation of ions for the soft region of the spectrum within the statistical fragmentation model, as well as for cumulative pions and photons. This approach is also applicable to other reactions. The differential spectra we calculated for the emission of protons in collisions of medium-mass ions at these energies are compared with the available experimental data obtained in the HADES collaboration (GSI).