Baryon fluctuations in extended linear sigma model

TL;DR

This paper investigates baryon number fluctuations and kurtosis near the critical end point in the phase diagram of strongly interacting matter using an extended linear sigma model, finding divergence at the CEP.

Contribution

It introduces calculations of baryon fluctuations in an extended linear sigma model and compares results with lattice and other models, highlighting divergence at the CEP.

Findings

Divergence of kurtosis at the critical end point

Baryon fluctuations are effectively modeled in the extended sigma model

Results agree with lattice and other effective models

Abstract

The existence and the location of the critical end point (CEP) between the crossover and the first order part of the chiral phase transition in the phase diagram of the strongly interacting matter is a heavily studied area of recent particle physics. The baryon number fluctuations and related quantities such as kurtosis and other susceptibility ratios, that are assumed to be good signatures of CEP, are calculated in an (axial)vector meson extended $(2 + 1)$ flavor Polyakov linear sigma model (EL$\sigma$M) at zero and finite $\mu_B$ . It is compared with the results of lattice as well as other effective model calculations. Divergence of the kurtosis is found at the critical end point.