A kinematically complete measurement of $K^+ \to \pi^+ \pi^0 \pi^0$ decays

Abstract.

In a kinematically complete setting, the $K^+ \to \pi^+ \pi^0 \pi^0$ decays of stopped $K^+$ were measured. In the frame work of the Weinberg polynomial expansion, the coefficients up to quadratic terms were deduced. The results are in good agreement with previous measurements and consistent with CP conservation expectations. The empirical $\Delta I=1/2$ rule is violated.