Color singlet suppression of quark-gluon plasma formation
  The rate of quark-gluon plasma droplet nucleation in superheated hadronic matter is calculated within the MIT bag model. The requirements of color singletness and (to less extent) fixed momentum suppress the nucleation rate by many orders of magnitude, making thermal nucleation of quark-gluon plasma droplets unlikely in ultrarelativistic heavy-ion collisions if the transition is first order and reasonably described by the bag model. 
Jes Madsen, Dan M. Jensen, Michael B. Christiansen (Univ.of Aarhus)