Electromagnetic interactions in $$\tilde U_{12} $$ symmetrysymmetry

Abstract

A model is developed for electromagnetic interactions of baryons and mesons in\(\tilde U_{12} \) symmetry along the lines which led Salam to the deduction of the nucleon magnetic moments. The main assumption is vector meson dominance. A modification of Salam's treatment allows to deduce μp≃1.7 and μn≃1.8 nuclear magnetons (expt. μp≃1.79, μn≃1.91) for the nucleon magnetic moments. Consistency of the model requires the existence of only one independent strong-interaction coupling constant and leads to a relation between baryon-baryon-meson and three-meson coupling constant, which is found valid up to a factor 1.2, tested at\(g_{\mathcal{N}\mathcal{N}\pi } \) andgρππ. As independent test the model allows the deduction of about 0.72 MeV partial decay width for ω→π0+γ (expt. (0.9±0.2) MeV) and of 0.8·10−16s for the lifetime of π0→2γ (expt. (1.05±0.2)·10−16s).