  To model the dynamics of the chiral order parameter in a far from equilibrium
QCD phase transition, we consider quenching in the O(4) linear sigma model. We
summarize arguments and numerical evidence which show that in the period
immediately following the quench arbitrarily long wavelength modes of the pion
field are amplified. This results in large regions of coherent pion
oscillations, and could lead to dramatic phenomenological consequences in
ultra-relativistic heavy ion collisions. My talk was a description of work done
with Frank Wilczek. In these proceedings, I sketch our central results,
emphasizing several points that were raised in discussions at the conference.
