Hadronic vs. partonic J/psi production in the Statistical Hadronization   Model
  Assuming the Statistical Hadronization Model and charm flavour conservation, one can quantify the deviation of charm and anti-charm quarks from chemical equilibrium both in the hadronic phase and in the quark-gluon plasma. By linking the hadronic fireball volume and the corresponding plasma source volume via entropy conservation as proposed by Grandchamp et al., a direct comparison between the $J/\psi$ yields in both pictures can be used to obtain limits for the charm quark mass in the medium. 
Philipp B. Bahavar, Jan Uphoff, Carsten Greiner
hep-ph nucl-th