Chiral Symmetry restoration from the hadronic regime

TL;DR

This paper reviews recent theoretical progress on QCD chiral symmetry restoration at finite temperature, emphasizing the role of effective theories, Ward identities, and unitarized interactions in understanding meson behavior and phase transition indicators.

Contribution

It introduces new Ward identities linking susceptibilities and condensates, and highlights the significance of the thermal $f_0(500)$ state in chiral transition descriptions.

Findings

Ward identities explain lattice meson mass behavior.

Unitarized interactions are crucial for the scalar susceptibility.

The thermal $f_0(500)$ state influences the chiral transition.

Abstract

We discuss recent advances on QCD chiral symmetry restoration at finite temperature, within the theoretical framework of Effective Theories. $U(3)$ Ward Identities are derived between pseudoscalar susceptibilities and quark condensates, allowing to explain the behaviour of lattice meson screening masses. Unitarized interactions and the generated $f_0(500)$ thermal state are showed to play an essential role in the description of the transition through the scalar susceptibility