2012/01/26 by L. M. Satarov, A. B. Larionov, I. N. Mishustin · 1 citation
Physics and Astronomy · #Equation of state #Fermi Gamma-ray Space Telescope #Hadron #High-Energy Particle Collisions Research #Ideal gas #Non-equilibrium thermodynamics #Nuclear matter #Pulsars and Gravitational Waves Research #Quantum Chromodynamics and Particle Interactions #Thermal #Thermal equilibrium #nucl-th
paper · pdf · doi:10.1103/physrevc.85.054910
23 pages, 12 figures
arxiv created 2012/01/26 · openalex publication_date 2012/05/18 · arxiv updated 2013/05/29 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We consider a spherical volume of hot and dense hadronic matter (fireball) expanding into a vacuum. It is assumed that initially the fireball matter is in local thermal and chemical equilibrium with vanishing collective velocity. The time evolution of the fireball is studied in parallel within the Giessen Boltzmann-Uehling-Uhlenbeck transport model and an ideal hydrodynamic model. The equation of state of an ideal hadronic gas is used in the hydrodynamic calculation. The same set of hadronic species is used in transport and fluid-dynamical simulations. Initial coordinates and momenta of hadrons in transport simulations have been randomly generated by using the Fermi and Bose distributions for (anti)baryons and mesons. The model results for radial profiles of densities and collective velocities of different hadronic species are compared at different times. We find that two considered models predict essential differences in time evolution of hadron abundances, which are especially pronounced for hyperonic species. This gives an evidence of a strong deviation from chemical equilibrium in expanding hadronic matter.