A consistent analysis on QCD phase diagram and meson spectra in the improved soft-wall AdS/QCD

Abstract

We present a consistent analysis on QCD phase diagram and meson spectra based on the improved soft-wall AdS/QCD. The equations of motion for the octet pseudoscalar, vector and axial-vector mesons with $2+1$ flavors are derived to calculate the octet meson spectra and relevant decay constants, by which the model parameters are determined. The chemical potential effects on chiral thermal transition are investigated, which enables us to obtain the QCD phase diagram in the $\\mu-T$ plane. It is shown that the critical end point (CEP) linking the crossover transition with the first-order phase transition still exists and locates at $(\\mu_B, T_c) \\simeq (390 MeV, 145 MeV)$. The crossover line and the location of CEP resulted from the model agree with both the lattice result and the experimental analysis from relativistic heavy-ion collisions. We find that the improved soft-wall AdS/QCD model can provide a consistent description for both the chiral phase diagram and the main properties of low-energy hadron physics in the $2+1$ flavor case.