SU(3)-symmetry breaking and theK20→π0γγdecay

Abstract

The parity-conserving decay $K_2^0\to {\pi }^0\gamma \gamma$ is studied using vector gauge fields with current mixing. The effects of SU(3)-symmetry breaking are included in the $\mathrm{PVV}$ vertices and the "simplest" $\Delta S=1\mathrm{}$ Hamiltonian (with a minimum of neutral currents) consistent with $\Delta I=\frac{1}{2}$ is employed. The calculated decay rate is compared to previous theoretical estimates as well as to the current experimental upper limit for the decay.