Chiral Phase Transition with 2+1 quark flavors in an improved soft-wall AdS/QCD Model

TL;DR

This paper investigates the chiral phase transition with 2+1 quark flavors using an improved soft-wall AdS/QCD model, revealing a phase diagram consistent with lattice results and identifying a tricritical point.

Contribution

It introduces an improved soft-wall AdS/QCD model capable of analyzing the (m_{u,d}, m_s) phase diagram and identifying a tricritical point in the chiral transition.

Findings

Phase diagram aligns with standard lattice and theoretical expectations.

First clear evidence of a tricritical point in bottom-up AdS/QCD.

Detailed analysis of quark condensates across different quark masses.

Abstract

We study the chiral phase transition with 2 + 1 quark flavors in an improved soft-wall AdS/QCD model, which can produce the light meson spectrum and many other low-energy quantities consistent with experiments in the two-flavor case. The chiral transition behaviors of the quark condensates at different quark masses are analysed in detail, and the (m_{u,d}, m_s) phase diagram for the quark sector has been obtained from the improved soft-wall model. We find that the features of the calculated phase diagram are completely consistent with the standard scenario, which is supported by lattice simulations and theoretical arguments. The evidence of a tricritical point on the m_{u,d} = 0 boundary of the (m_{u,d}, m_s) phase diagram is first clearly presented in the bottom-up AdS/QCD.