Freeze out in hydrodynamical models
  We study the effects of strict conservation laws and the problem of negative contributions to final momentum distribution during the freeze out through 3-dimensional hypersurfaces with space-like normal. We study some suggested solutions for this problem, and demonstrate it on one example. 
Cs.Anderlik, L.P.Csernai, F.Grassi, W. Greiner, Y.Hama, T.Kodama,   Zs.I.Lazar, V. Magas, H. Stoecker