Difference between the Cabibbo AnglesθAandθVand the DecaysK→2πin a Covariant Quark Model

Abstract

Formulas for the amplitudes of the three weak hadronic decays $K^{+}\to {\pi }^{+}+{\pi }^0$, ${K_1}^0\to {\pi }^{+}+{\pi }^{-}$, and ${K_1}^0\to 2{\pi }^0$ are derived within the framework of a covariant quark model. The result is that for the explanation of the observed $K^{+}\to {\pi }^{+}+{\pi }^0$ decay a slight difference between the Cabibbo angles ${\theta }_A$ and ${\theta }_V$ is required. A sum rule for the three decay widths and a calculation of the ${K_1}^0$ decay width are in fairly good agreement with the experimental data.