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With the aim of developing the hydrodynamic approach to describing collisions of intermediate-energy heavy ions, it is proposed to solve simultaneously the equations of hydrodynamics and the kinetic equation. This makes it possible to include the nonequilibrium component in the present analysis and to describe successfully experimental data obtained at Institute for Theoretical and Experimental Physics (ITEP, Moscow) for the double-differential cross sections of the emission of cumulative protons, pions, and photons in collisions carbon nuclei with a beryllium target in the energy range between 2.0 and 3.2 GeV per nucleon. The correction for the microcanonical distribution and the contribution of the fragmentation process to the proton yield are taken into account in describing these spectra. The resulting description of these experimental data turns out to be better than the descriptions based on cascade models and models of quantum molecular dynamics. A comparison with other reactions and approaches is performed. It turns out that effects of short-range correlations are included in the proposed approach, since it provides a successful description of experimental hard-photon spectra, which are described within molecular dynamics only upon adding a high-momentum component. [ABSTRACT FROM AUTHOR]

The energy dependence of the effective temperatures of charged kaons, ϕ and Ω produced in Au + Au collisions at the Relativistic Heavy Ion Collider (RHIC) Beam Energy Scan (BES) energies are presented. At energies around s N N ∼ 8 GeV, there is a sudden change in the energy dependence of K ± and ϕ effective temperatures, while at higher energies a slower, continuous rise up to s N N = 2. 7 6 TeV is observed. This behavior is similar with previous SPS results and could indicate the onset of deconfinement in this energy range. The Ω effective temperatures increase with energy and no plateau-like behavior is evidenced by the data. [ABSTRACT FROM AUTHOR]

Hard photon emitted from energetic heavy ion collisions is of very interesting since it does not experience the late-stage nuclear interaction, therefore it is useful to explore the early-stage information of matter phase. In this work, we investigated the directed flow and elliptic flow for proton-neutron bremsstrahlung hard photons in intermediate energy heavy-ion collisions. The positive directed flow and negative elliptic flow of directed photons are illustrated and they seem to be anti-correlated to the free proton's flow. Also we calculated the two-photon correlation functions from which the information of photon source was extracted, and while two-photon azimuthal correlations are presented as a good method to extract the elliptic flow parameter v2 of direct hard photons. [ABSTRACT FROM AUTHOR]

The threshold energies of radial flow in central collisions are investigated within an isospin dependent quantum molecular dynamics model using three different forms of symmetry energy. It is found that the neutron-rich system had smaller threshold energy of radial flow and this quantity depends on the form of symmetry potential. It indicates that the threshold energy of radial flow can provide a new method to determine the symmetry energy of asymmetric nuclear matter. [ABSTRACT FROM AUTHOR]