New results on kaon decays from NA48/2

Abstract

Recent results from the NA48/2 experiment are presented. The $\pi\pi$ scattering lengths $a_0^0$ and $a_0^2$ have been extracted from the cusp in the $M_{00}^2$ distribution of $K^\pm \to \pi^\pm \pi^0 \pi^0$ decays and from the $K^\pm \to \pi^+ \pi^- e^\pm \nu$ phase shift $\delta$. Branching ratios and form factors have been measured for {$K^\pm \to \pi^\pm \gamma \gamma$}, {$K^\pm \to \pi^\pm \gamma e^+ e^-$} and {$K^\pm \to \pi^\pm e^+ e^-$} decays and are also summarized here.