2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/42346Evolution process could be calculated from the relativistic hydrodynamic equation with certain estimated initial conditions about a single spherical fireball here. So one could estimate a kind of initial condition qualitatively with a possible energy density about $ε_0\approx 1.9$ $GeV/fm^3$, based on this process to fit the experimental data at thermal freeze-out. The evolution from a cylindrical fireball will be discussed simply in a later chapter.9 pages, 8 figuresHigh Energy Physics - Phenomenologytext