Resolution of the SU(3) Puzzle:<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mfrac><mml:mrow><mml:mi>Γ</mml:mi><mml:mo>(</mml:mo><mml:mi>η</mml:mi><mml:mo>→</mml:mo><mml:mi>γ</mml:mi><mml:mi>γ</mml:mi><mml:mo>)</mml:mo></mml:mrow><mml:mrow><mml:mi>Γ</mml:mi><mml:mo>(</mml:mo><mml:mrow><mml:msup><mml:mrow><mml:mi>π</mml:mi></mml:mrow><mml:mrow><mml:mn>0</mml:mn></mml:mrow></mml:msup></mml:mrow><mml:mo>→</mml:mo><mml:mi>γ</mml:mi><mml:mi>γ</mml:mi><mml:mo>)</mml:mo></mml:mrow></mml:mfrac></mml:math>

Using the Duffin-Kemmer-Petiau (DKP) description of mesons, we are able to render simple SU(3) theory consistent with the supposedly "large" experimental value of $\frac{\ensuremath{\Gamma}(\ensuremath{\eta}\ensuremath{\rightarrow}\ensuremath{\gamma}\ensuremath{\gamma})}{\ensuremath{\Gamma}({\ensuremath{\pi}}^{0}\ensuremath{\rightarrow}\ensuremath{\gamma}\ensuremath{\gamma})}=129\ifmmode\pm\else\textpm\fi{}33$. After discussing $\ensuremath{\eta}\ensuremath{-}{\ensuremath{\eta}}^{\ensuremath{'}}$ mixing we make a prediction [uncertain because of large errors in ${\ensuremath{\Gamma}}_{\mathrm{tot}}^{\mathrm{expt}}({\ensuremath{\pi}}^{0})$ and ${\ensuremath{\Gamma}}_{\mathrm{tot}}^{\mathrm{expt}}(\ensuremath{\eta})$] of ${\ensuremath{\Gamma}}^{\mathrm{DKP}}({\ensuremath{\eta}}^{\ensuremath{'}}\ensuremath{\rightarrow}\ensuremath{\gamma}\ensuremath{\gamma})={0.32}_{\ensuremath{-}0.32}^{+0.99}$ keV. This is at least 1-2 orders of magnitude lower than the Klein-Gordon (KG) prediction, ${\ensuremath{\Gamma}}^{\mathrm{KG}}({\ensuremath{\eta}}^{\ensuremath{'}}\ensuremath{\rightarrow}\ensuremath{\gamma}\ensuremath{\gamma})=52\ifmmode\pm\else\textpm\fi{}24$ keV, which in fact is almost ruled out by upper limits set by recent experiments.