Resonance States in an Effective Chiral Hadronic Model

TL;DR

This paper investigates how hadronic resonances influence the QCD phase diagram using an effective chiral SU(3) model, highlighting the impact of resonance couplings on phase transition characteristics and the potential existence of a critical end point.

Contribution

It demonstrates that varying resonance couplings in a chiral model significantly alters the phase transition nature and the likelihood of a critical end point, aligning with lattice QCD results.

Findings

Large vector couplings favor a smooth crossover transition.

Resonance effects modify the position and existence of the critical end point.

Results are consistent with lattice QCD at zero baryochemical potential.

Abstract

With an effective chiral flavour SU(3) model we show the effect of hadronic resonances on the QCD phase diagram. We state that varying the resonance couplings to the scalar and vector fields affects the order and location of the phase transition, the possible existence of a critical end point (CEP), and the thermodynamic properties. We present (strange) quark number susceptibilities at zero baryochemical potential and at three different points at the phase transition. Comparing results to lattice QCD, we state that reasonable large vector couplings limit the phase transition to a smooth crossover ruling out a CEP.