Strange matter and kaon to pion ratio in SU(3) PNJL model

TL;DR

This paper uses the SU(3) PNJL model to analyze strange matter and the kaon to pion ratio, revealing how the model explains the 'horn' phenomenon and signals of the critical end point in heavy-ion collisions.

Contribution

It demonstrates how the SU(3) PNJL model can describe the kaon to pion ratio behavior and the emergence of the 'horn' in relation to the phase transition and critical end point.

Findings

Splitting of kaon and anti-kaon masses due to density effects.

The 'horn' in the K/π ratio is linked to the phase transition.

K+/π+ ratio rises near the critical end point.

Abstract

The behavior of strange matter in the frame of the SU(3)Polyakov-loop extended Nambu-Jona-Lasinio model including $U_A(1)$ anomaly is considered. We discuss the appearance of a peak in the ratio of the number of strange mesons to non-strange mesons known as the "horn". The PNJL model gives a schematic description of the chiral phase transition and meson properties at finite temperature and density. Using the model, we can show that the splitting of kaon and anti-kaon masses appears as a result of introduction of density. This may explain the difference in the $K^+/\pi^+$ ratio and $K^-/\pi^-$ ratio at low $\sqrt{s_{NN}}$ and their tendency to the same value at high $\sqrt{s_{NN}}$. We also show that the rise in the ratio $K^+/\pi^+$ appears near CEP when we build the $K^+/\pi^+$ ratio along the phase transition diagram and it can be considered as a critical region signal.