10th Asian Triangle Heavy-Ion Conference - ATHIC 2025

Chiral cross-over in Hadron Resonance Gas model

15 Jan 2025, 11:40

13m

1. QCD Phase Diagram, criticality and fluctuations Parallel C

Speaker

Deeptak Biswas (National Institute of Science Education and Research (NISER))

Description

We investigate the behavior of the chiral condensate within a Hadron Resonance Gas model, incorporating repulsive mean-field interactions among baryons. By calibrating the strength of these interactions to match the lattice QCD estimations of higher-order baryon charge susceptibilities, we can extend this model to higher baryon densities, where lattice QCD encounters challenges due to the sign problem. Our analysis focuses on estimating the chiral pseudocritical line by studying the temperature dependence of the chiral condensate as a function of ${\mu }_B$. We describe the crossover line using a parametric form, $T_{pc}({\mu }_B)/T_{pc}(0)=1-{\kappa }_2({\mu }_B/T_{pc}(0){)}^2-{\kappa }_4({\mu }_B/T_{pc}(0){)}^4$. Our findings yield ${\kappa }_2=0.0150(2)$ and ${\kappa }_4=3.1(6)\cdot {10}^{-5}$. The agreement of ${\kappa }_2$ with lattice QCD results is excellent, and our study marks the first identification of a non-negligible ${\kappa }_4$ term within this context. Moreover, the separation between the freeze-out curve and the pseudo-critical line widens at higher densities, suggesting a prolonged hadronic phase at lower collision energies.

Presentation materials

ATHIC_DB_2025.pdf