Description of the nuclear stopping process within the anisotropic thermo-hydrodynamics

摘要

Fluid-dynamical models have proven useful in describing gross properties of colliding nuclei at high energies~1. The space-time evolution of a few relevant observables during the collision process is followed by exploiting the conservation of baryon charge and energy and momentum and the concept of partial local equilibrium. The appropriate choice of the equation of state, the determination of which is one of the ultimate goals in performing heavy-ion experiments, and the phenomenological transport coefficients ensure a wide range of applicability of fluid models. The finite momentum degradation length of the nucleons is taken into account in the multi-fluid models. Despite of their wide applicability, the fluid models encounter also some conceptual problems, such as (i) the determination of state-dependent coupling strengths between different fluid components, (ii) the proper description of hte nuclear stopping process and local equilibrtion process when regarding to the finite nucleon mean free path.