Dyson-Schwinger Equations of Chiral Chemical Potential

We discuss the chiral phase transition of quantum chromodynamics （QCD） with a chiral chemical potential μ5 as an additional scale. Within the framework of Dyson-Schwinger equations, we focus particularly on the behavior of the widely accepted as well as interesting critical end point （CEP）, using a separable gluon propagator and a Gaussian gluon propagator. We find that there may be no CEP5 in the T-μ5 plane, and the phase transition in the T μ5 plane might be totally crossover. Our results have apparent consistency with the Lattice QCD calculation. On the other hand, our study may also provide some useful hints to some other studies related to μ5.

Nonextensive effects on QCD chiral phase transition with a chiral chemical potential

In this study,we investigate the QCD chiral phase diagram in the presence of a chiral chemical potential μ based on nonextensive statistical mechanics.A feature of this new statistic is a dimensionless nonextensivity parameter q,which summarizes all possible effects violating the assumptions of Boltzmann-Gibbs(BG)statistics(when q→1,it returns to the BG case).Within the nonextensive Polyakov-Nambu-Jona-Lasinio model,we find that as μ increases,the critical end point(CEP)in the T-μ plane continues to CEP_(5)in the T-μ plane,and nonextensive effects have a significant impact on the evolution from the CEP to CEP_(5).Generally,with an increase in q,both the CEP and CEP_(5)move in the direction of a lower temperature T and larger chemical potentialμ(μ_(5)).In addition,we find that chiral charge density ngenerally increases with T,μ,μ_(5),and q.Our study may provide useful hints about lattice QCD and relativistic heavy-ion collision experiments.