Model prediction for temperature dependence of meson pole masses from lattice QCD results on meson screening masses

Abstract

We propose a practical effective model by introducing temperature ($T$) dependence to the coupling strengths of four-quark and six-quark Kobayashi-Maskawa-'t Hooft interactions in the 2+1 flavor Polyakov-loop extended Nambu-Jona-Lasinio model. The $T$ dependence is determined from LQCD data on the renormalized chiral condensate around the pseudocritical temperature $T_c^{\chi }$ of chiral crossover and the screening-mass difference between $\pi$ and $a_0$ mesons in $T>1.1T_c^{\chi }$ where only the $U(1{)}_{\mathrm{A}}$-symmetry breaking survives. The model well reproduces LQCD data on screening masses $M_{\xi }^{\mathrm{scr}}(T)$ for both scalar and pseudoscalar mesons, particularly in $T\ge T_c^{\chi }$. Using this effective model, we predict meson pole masses $M_{\xi }^{\mathrm{pole}}(T)$ for scalar and pseudoscalar mesons. For ${\eta }^{\prime }$ meson, the prediction is consistent with the experimental value at finite $T$ measured in heavy-ion collisions. We point out that the relation $M_{\xi }^{\mathrm{scr}}(T)-M_{\xi }^{\mathrm{pole}}(T)\approx M_{{\xi }^{\prime }}^{\mathrm{scr}}(T)-M_{{\xi }^{\prime }}^{\mathrm{pole}}(T)$ is pretty good when $\xi$ and ${\xi }^{\prime }$ are scalar mesons, and show that the relation $M_{\xi }^{\mathrm{scr}}(T)/M_{{\xi }^{\prime }}^{\mathrm{scr}}(T)\approx M_{\xi }^{\mathrm{pole}}(T)/M_{{\xi }^{\prime }}^{\mathrm{pole}}(T)$ is well satisfied within 20% error when $\xi$ and ${\xi }^{\prime }$ are pseudoscalar mesons and also when $\xi$ and ${\xi }^{\prime }$ are scalar mesons.

Comments: 13 pages, 14 figures