Vector-Dominance Model, Partial Conservation of the Axial-Vector Current, and the Decoupling ofπρω

Abstract

We show that partial conservation of the axial-vector current and vector dominance together imply that ${g}_{\ensuremath{\pi}\ensuremath{\rho}\ensuremath{\omega}}=0$. We discuss the relevance of this result to the failure of vector dominance in polarized photoproduction of pions. We also provide a simple interpretation of the $\ensuremath{\rho}$-meson mass shift in photoproduction experiments based on unitarity.