XQCD 2018

The SU(3) flavor parity-doublet quark-hadron model is used to investigate the phase diagram of QCD matter. The quark sector of the model is tuned to the $\mu_B=0$ lattice QCD data on trace anomaly. The structure of the baryon number susceptibilities in the temperature/chemical potential plane is studied in some detail. The model predicts three phase transitions - nuclear first-order liquid-gas phase transition, chiral symmetry restoration, and deconfinement transition. At $\mu_B=0$, a good agreement with the corresponding lattice data is obtained. The deviations from the free hadron gas baseline in the crossover temperature region at $\mu_B=0$ are mainly attributed to the leftover of the liquid-gas transition in nuclear matter, the chiral phase transition determines the baryon fluctuations at much higher $\mu_B$, and at even higher baryon densities the behavior of fluctuations is controlled by deconfinement transition.