New measurement of $K^{+}\to \ddot{I}{€}^{+}\hat{I}½\bar{\hat{I}}½$ branching ratio at the NA62 experiment

Xiafei Chang, for the NA62 Collaboration

The ultra-rare decay $K^{+}\to \ddot{I}{€}^{+}\hat{I}½\bar{\hat{I}}½$ is a golden mode in flavor physics. The Standard Model prediction for its branching ratio is below $10^{-10}$. This decay mode is highly s…