Effective Lagrangians and thermal resonances under extreme conditions

TL;DR

This paper investigates the behavior of hadrons under extreme temperature and chemical potential conditions, highlighting the role of thermal resonances in chiral symmetry restoration and developing an effective Lagrangian for axial chemical potential.

Contribution

It introduces a framework combining Unitarized Chiral Perturbation Theory and effective Lagrangians to study hadron properties under extreme conditions, emphasizing thermal resonances and chemical potential effects.

Findings

Thermal resonances influence chiral and $U(1)_A$ restoration.

Constructed an effective Lagrangian at non-zero chemical potential.

Analyzed the impact of thermal effects on hadron dynamics.

Abstract

We analyze various problems related to the physics of hadrons under extreme conditions of temperature and chemical potentials. On the one hand, we show that the thermal resonances $f_0(500)$ and $K_0^*(700)$, generated in the framework of Unitarized Chiral Perturbation Theory $\pi\pi$ and $K\pi$ scattering at finite temperature, play an essential role concerning chiral and $U(1)_A$ restoration. On the other hand, a low-energy effective Lagrangian has been constructed within ChPT at non-zero chemical potential, which we discuss here for an axial chemical potential.