New results on kaon decays from NA48/2

Abstract

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