Density fluctuations and chiral phase transition

Abstract

Based on an effective QCD Lagrangian, we discuss the properties of charge-density fluctuations in the vicinity of chiral phase transition. We explore thermodynamics in the presence of spinodal phase separation. We show that the appearance of spinodal decomposition in a non-equilibrium first-order phase transition results in divergence of the charge-density fluctuations related to the electric charge and baryon number conservation. Consequently, divergent fluctuations at the chiral phase transition are not only attributed to the critical end point but also to the first-order phase transition if the spinodal phase separation takes place. Based on the mean field dynamics, the critical exponents for these singular behavior of charge susceptibilities are also discussed.