2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/149004Employing $U(3)_L\times U(3)_R$ chiral field theory, we find that Dashen's theorem, which holds for pseudoscalar mesons, can be generalized to the sector of axial-vector mesons, however, fails for vector mesons.LaTeX file, 16 pages, no figuresHigh Energy Physics - Phenomenologytext