2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/176520The claim that the light quark mass ratio (m_d - m_u)/m_s can be extracted from the decay width ratio Gamma(eta' -> pi^0 pi^+ pi^-)/Gamma(eta' -> eta pi^+ pi^-) is critically investigated within a U(3) chiral unitary framework. The influence of the recent VES data on the eta' -> eta pi^+ pi^- decay is also discussed.9 pages, 1 figure, 6 tablesHigh Energy Physics - PhenomenologyHigh Energy Physics - ExperimentNuclear ExperimentNuclear TheoryOn the extraction of the quark mass ratio (m_d - m_u)/m_s from Gamma(eta' -> pi^0 pi^+ pi^-)/Gamma(eta' -> eta pi^+ pi^-)text