QCD critical end point from a realistic PNJL model

Kun Xu,Mei Huang,Zhibin Li

doi:10.1051/epjconf/201819200019

Abstract

With parameters fixed by critical temperature and equation of state at zero baryon chemical potential, a realistic Polyakov-Nambu-Jona-Lasinio (rPNJL) model predicts a critical end point of chiral phase transition at (μEB = 720MeV; TE = 93MeV). The extracted freeze-out line from heavy ion collisions is close to the chiral phase transition boundary in the rPNJL model, and the kurtosis kσ2 of baryon number fluctuations from the rPNJL model along the experimental freeze-out line agrees well with the BES-I measurement. Our analysis shows that the dip structure of measured kσ2 is determined by the relationship between the freeze-out line and chiral phase transition line at low baryon density region, and the peak structure can be regarded as a clean signature for the existence of CEP.

Highlights

Exploring Quantum Chromodynamics (QCD) phase structure and understanding properties of QCD matter under extreme conditions are main topics of heavy ion collisions
We can see that the dip structure of measured κσ2 is determined by the relationship between the freeze-out line and chiral phase transition line at low baryon density region, and the peak structure can be regarded as a clean signature for the existence of critical end point (CEP)
We have investigated the kurtosis of the baryon number fluctuations κσ2 in a reparameterized realistic Polyakov-loop improved NJL (PNJL) model, in which the critical temperature, equation of state and baryon number fluctuations are in good agreement with lattice data at zero chemical potential

Summary

Introduction

Exploring Quantum Chromodynamics (QCD) phase structure and understanding properties of QCD matter under extreme conditions are main topics of heavy ion collisions. Still we can extract some useful information from model studies, e.g., the peak structure of κσ along the freeze-out line can be used as a clean signature for the existence of CEP, and the peak location of the measured κσ is close to the real QCD CEP mountain [12, 13]. In this talk, we show the results from a realistic Polyakov–Nambu–Jona-Lasinio (rPNJL) model [13]. It is interesting to observe that the kurtosis κσ produced from the rPNJL model along the experimental freeze-out line agrees with BES-I data well!

Model setup

Numerical results

Summary