Chemical equilibration due to heavy Hagedorn states
  A scenario of heavy resonances, called massive Hagedorn states, is proposed which exhibits a fast ($t\approx 1$ fm/c) chemical equilibration of (strange) baryons and anti-baryons at the QCD critical temperature $T_c$. For relativistic heavy ion collisions this scenario predicts that hadronization is followed by a brief expansion phase during which the equilibration rate is higher than the expansion rate, so that baryons and antibaryons reach chemical equilibrium before chemical freeze-out occurs. 
C. Greiner, P. Koch-Steinheimer, F. M. Liu, I. A. Shovkovy and H.   Stoecker