Chiral criticality and the role of repulsive interactions in hot hadronic matter

TL;DR

This paper investigates how chiral symmetry restoration and repulsive interactions influence net-baryon number fluctuations in hot hadronic matter, emphasizing the importance of their combined effects near the chiral crossover.

Contribution

It demonstrates that critical chiral dynamics uniquely determine cumulant properties, which cannot be captured by models considering only repulsive interactions.

Findings

Cumulant properties are linked to critical chiral dynamics.

Phenomenological models with only repulsive interactions fail to reproduce cumulant features.

A self-consistent treatment of chiral effects and repulsive interactions is necessary.

Abstract

We explore fluctuations of the net-baryon number density in hadronic matter at vanishing chemical potential. We discuss the interplay between chiral dynamics and repulsive interactions and their influence on the properties of these fluctuations near the chiral crossover in the parity doublet model. We find that the characteristic properties of cumulants are entirely linked to the critical chiral dynamics and cannot be reproduced in phenomenological models, which account only for repulsive interactions. Consequently, a description of the higher-order cumulants of the net-baryon density requires a self-consistent treatment of the chiral in-medium effects and repulsive interactions.