Chemical Equilibration and the Hadron-QGP Phase Transition
  We discuss recent experimental results on hadron multiplicities in ultra-relativistic nuclear collisions. The data for central collisions are in quantitative agreement with predictions of a thermal model assuming full chemical equilibration. It is argued that this provides strong, albeit indirect, evidence for the formation of a partonic phase in the collision prior to hadron production. 
Peter Braun-Munzinger