Modified Boltzmann Transport Equation and Freeze Out
  We study Freeze Out process in high energy heavy ion reaction. The description of the process is based on the Boltzmann Transport Equation (BTE). We point out the basic limitations of the BTE approach and introduce Modified BTE. The Freeze Out dynamics is presented in the 4-dimensional space-time in a layer of finite thickness, and we employ Modified BTE for the realistic Freeze Out description. 
L.P. Csernai, V.K. Magas, E. Molnar, A. Nyiri and K. Tamosiunas