Comparing symmetry restoration trends for meson masses and mixing angles in the QCD-like three quark flavor models

TL;DR

This study investigates how fermionic vacuum fluctuations influence meson masses, mixing angles, and chiral symmetry restoration in QCD-like models, revealing smoother symmetry restoration and altered anomaly effects.

Contribution

It provides explicit analytical expressions and compares models with and without fermionic vacuum effects, highlighting their impact on meson properties and symmetry restoration trends.

Findings

Fermionic vacuum fluctuations lead to smoother chiral symmetry restoration.

Presence of vacuum terms increases the melting of strange condensate.

Fermionic vacuum effects significantly modify the role of the $U_A(1)$ anomaly.

Abstract

We are computing the modifications for the scalar and pseudoscalar meson masses and mixing angles due to the proper accounting of fermionic vacuum fluctuation in the framework of the generalized 2+1 flavor quark meson model and the Polyakov loop augmented quark meson model(PQM). The renormalized contribution of the divergent fermionic vacuum fluctuation at one loop level makes these models effective QCD-like models. It has been explicitly shown that analytical expressions for the model parameters, meson masses, and mixing angles do not depend on any arbitrary renormalization scale. We have investigated how the incorporation of fermionic vacuum fluctuation in quark meson and PQM models qualitatively and quantitatively affects the convergence in the masses of the chiral partners in pseudoscalar ($\pi$, $\eta$, $\eta'$, $K$) and scalar ($\sigma$, $a_0$, $f_0$, $\kappa$) meson nonets as the temperature is varied on the reduced temperature scale. Comparison of present results in the quark meson model with vacuum term and PQM model with vacuum term with the already existing calculations in the bare 2+1 quark meson and PQM models, shows that the restoration of chiral symmetry becomes smoother due to the influence of the fermionic vacuum term. We find that the melting of the strange condensate registers a significant increase in the presence of the fermionic vacuum term and its highest melting is found in the PQM model with vacuum term. The role of the $U_A(1)$ anomaly in determining the isoscalar masses and mixing angles for the pseudoscalar ($\eta$ and $\eta'$) and scalar ($\sigma$ and $f_0$) meson complex has also been significantly modified due to the fermionic vacuum correction. In its influence, the interplay of chiral symmetry restoration and the setting up of the $U_A(1)$ restoration trends have also been shown to be significantly modified.