2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/191223In fluid dynamical models the freeze out of particles across a three dimensional space-time hypersurface is discussed. The calculation of final momentum distribution of emitted particles is described for freeze out surfaces, with both space-like and time-like normals, taking into account conservation laws across the freeze out discontinuity.10 pages, 4 figuresNuclear Theorytext