Chiral symmetry restoration and properties of Goldstone bosons at finite temperature*

We study chiral symmetry restoration by analyzing thermal properties of QCD's (pseudo-)Goldstone bosons, especially the pion. The meson are obtained from spectral densities mesonic imaginary-time correlation functions. To obtain functions, we solve Dyson-Schwinger equations and inhomogeneous Bethe-Salpeter in leading symmetry-preserving rainbow-ladder approximation. In limit, pion its partner sigma degenerate at critical temperature $T_c$. At $T \gtrsim T_c$, it is found that rapidly dissociates, which signals deconfinement phase transition. Beyond dissociation can be used to define pseudo-critical crossover, consistent with maximum point susceptibility. parallel analysis for kaon pseudoscalar $s\bar{s}$ suggests heavy mesons may survive above