2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/211370We study the vector-axialvector mixing in a hot medium and its evolution toward the chiral phase transition using different symmetry restoration scenarios based on the generalized hidden local symmetry framework. We show that the presence of the $a_1$ meson reduces the vector spectral function around $ρ$ meson mass and enhances it around $a_1$ meson mass. The coupling strength of $a_1$ to $ρ$ and $π$ vanishes at the critical temperature due to the degenerate $ρ$-$a_1$ masses. This feature holds rigorously in the chiral limit and still stays intact to good approximation for the physical pion mass.v2:11 pages, 6 figures, reorganized and expanded the text, new plots and references added, main result and conclusions unchangedHigh Energy Physics - PhenomenologyNuclear Theorytext