Soft Modes at the Critical End Point in the Chiral Effective Models
  At the critical end point in QCD phase diagram, the scalar, vector and entropy susceptibilities are known to diverge. The dynamic origin of this divergence is identified within the chiral effective models as softening of a hydrodynamic mode of the particle-hole--type motion, which is a consequence of the conservation law of the baryon number and the energy. 
H. Fujii (U Tokyo, Komaba) and M. Ohtani (RIKEN)