Hydrodynamics of an expanding fireball

A set of relativistic hydrodynamic equations is solved numerically on the basis of the flux-corrected SHASTA method for one-, two-, and three-dimensional geometries. The accuracy of the proposed method is demonstrated via a comparison with exact analytic solutions for the one-dimensional Riemann problem and a boost-invariant longitudinal expansion in the Bjorken model. The example of an expanding three-dimensional fireball for which initial conditions approximately correspond to PbPb collisions at an energy of about 160 GeV per nucleon is considered. This example indicates that the presumed dynamics of the expansion may affect substantially the results of an analysis of in-medium properties of hadrons that relies on data from experiments with leptons.     

Properties of hot and dense nuclear matter in a mixed phase

The QCD phase transition is treated within a statistical model taking into account the coexistence of interacting quark-gluon and hadron phases. Being in agreement with the recent lattice QCD data, this statistical mixed phase model predicts that the “softest point” of the equation of state, resulting in the longest-lived fireball effect, is atε _{sp ≈ 0.35}GeV/fm³. It is shown that this “softest point” is washed out at the baryon densities higher than the normal nuclear density. The approach is extended to include strangeness. Attention is drawn to the study of signatures for forming the mixed quark-hadron phase of nuclear matter in the collision energy rangeE _lab ≈ 2–10 GeV/A.     

A generalized quantum kinetic equation for models of relativistic nuclear dynamics

Zubarev’s method of non-equilibrium statistical operator is applied to problems of relativistic kinetic theory. Within this method, a generalized relativistic quantum kinetic equation for the relativistic Wigner function is derived with taking into account the drift term of the Vlasov type and the collision integral of the second order in particle interaction. It is shown that this result holds as well for gauge invariant theories in the case of slowly changing fields. An advantage of the developed approach is exemplified by the consideration of relativistic nuclear matter within the Walecka and Nambu-Jona-Lasinio models. Typical relativistic effects like retardation, spin degrees of freedom and antiparticle evolution are taken into consideration.     

A cascade-evaporation model for photonuclear reactions

Detailed and systematic Monte Carlo calculations have been performed for different characteristics of inelastic photonuclear reactions for an energy range of T_γ ≈ 50 MeV–1 GeV in the framework of the intranuclear cascade model taking into account the competition between particle evaporation and fission of excited residual nuclei. The calculated results agree well with experimental data. On the basis of the data listed it is possible to extrapolate the corresponding characteristics for intermediate energies and nuclei.     

Search for a mixed quark-hadron phase of QCD matter at the JINR nuclotron

Physics aspects of a JINR project to reach the planned 5 A GeV energy for the Au and U beams and to increase the bombarding energy up to 10 AGeV are discussed. The project aims to search for a possible formation of a strongly interacting mixed quark-hadron phase. The relevant problems are exemplified. The need for scanning heavy-ion interactions in bombarding energy, collision centrality, and isospin asymmetry is emphasized. The text was submitted by the authors in English.     

Vorticity and Particle Polarization in Relativistic Heavy-Ion Collisions

Physics of Atomic Nuclei - We review studies of vortical motion and the resulting global polarization of $$\Lambda$$ and $$\bar{\Lambda}$$ hyperons in heavy-ion collisions, in particular, within...     

Proton, deuteron, and triton emission in 14N+Ag interactions at an energy of 52 MeV per nucleon

The inclusive energy spectra and multiplicities of p, d, and t from the reactions ¹⁴N(Ag, X), X=p, d, t at E/A=52 MeV are measured. The experimental data are compared with the results obtained within the Dubna version of the cascade model and are analyzed on the basis of the moving-source model.