2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/191222The scale of a phenomenologically successful charge-symmetry-violating nucleon-nucleon interaction, that attributed to meson exchange with a $ΔI =1$ rho-omega transition, is set by the Coleman-Glashow SU(2) breaking tadpole mechanism. A single tadpole scale has been obtained from symmetry arguments, electromagnetic meson and baryon measured mass splittings, and the observed isospin violating ($ΔI=1$) decay $ω\to π^+π^-$. The hadronic realization of this tadpole mechanism lies in the $I = 1$ $a_0$ scalar meson. We show that measured hadronic and two-photon widths of the $a_0$ meson, with the aid of the Vector Meson Dominance model, recover the universal Coleman-Glashow tadpole scale.18 pages, 2 figures, to appear in Physical Review CNuclear Theorytext