Radiative decay width of the-meson

We present data on coherent ${\ensuremath{\rho}}^{\ensuremath{-}}$ production on nuclear targets and our application of the Primakoff formalism for extracting the radiative decay width for the transition ${\ensuremath{\rho}}^{\ensuremath{-}}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{\ensuremath{-}}\ensuremath{\gamma}$. Assuming the presence of both electromagnetic and strong contributions to coherent production, we obtain $\ensuremath{\Gamma}({\ensuremath{\rho}}^{\ensuremath{-}}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{\ensuremath{-}}\ensuremath{\gamma})=71\ifmmode\pm\else\textpm\fi{}7$ keV, a result in good agreement with SU(3).