Abstract
The 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→
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.