Asymptotic Symmetry, Particle Mixing, andKl3-Decay Branching Ratios

Abstract

A concept of asymptotic symmetry is formulated and applied to the determination of mixing parameters between the ${\pi }^0$, ${\eta }^0$, and ${\eta }^{{\prime }^0}\mathrm{}\left(958\right)\mathrm{}$ in broken SU(3) and SU(2) symmetries. One of the solutions gives rise to a rather large violation of the $\left|\Delta \overrightarrow{\mathrm{I}}\right|=\frac{1}{2}$ rule in the $K_{l3\mathrm{}}$ decays which is not inconsistent with present experiment.