Anisotropy as a Consequence of Pre-equilibrium Rescattering
  It is shown that azimuthal asymmetry in transverse momentum distribution of particles observed in non-central heavy ion collisions can originate from pre-equilibrium rescattering. The phenomenon is studied using computer simulation of expanding pion gas created in Pb+Pb 160 GeV/n collisions. Results obtained are discussed in comparison with experimental results of NA49 collaboration. Theoretical understanding of mechanism generating the asymmetry is presented. Conclusion about non-equilibrium properties of the phenomenon studied is drawn. 
Peter Filip