# Modeling chiral criticality

## TL;DR

This paper models the critical behavior of net-baryon-number fluctuations near the chiral transition in QCD matter, using the Polyakov-loop extended Quark-Meson model and the Functional Renormalization Group, and compares results with experimental data.

## Contribution

It introduces a detailed analysis of net-baryon-number cumulant ratios at the chiral transition using an advanced QCD-inspired model and FRG, providing insights into critical phenomena in heavy-ion collisions.

## Key findings

- Ratios of net-baryon-number cumulants show critical behavior near the phase transition.
- Model results are consistent with experimental fluctuations in nucleus-nucleus collisions.
- Criticality influences higher-order cumulant ratios significantly.

## Abstract

We discuss the critical properties of net-baryon-number fluctuations at the chiral restoration transition in matter at nonzero temperature and net-baryon density. The chiral dynamics of quantum chromodynamics (QCD) is modeled by the Polykov-loop extended Quark-Meson Lagrangian, that includes the coupling of quarks to temporal gauge fields. The Functional Renormalization Group is employed to account for the criticality at the phase boundary. We focus on the ratios of the net-baryon-number cumulants, $\chi_B^n$, for $1\leq n\leq 4$. The results are confronted with recent experimental data on fluctuations of the net-proton number in nucleus-nucleus collisions.