The NA48/2 experiment at the CERN SPS was designed to search for CP
violation in K±→π±π+π− decays. It has also allowed studying several rare
decay processes of charged kaons to test chiral perturbation theory.
With data samples of ~10^6 Ke4 decays, precise values of a0 and a2, the
isospin 0 and 2 S-wave pp scattering lengths, can be extracted with an
unprecedented experimental precision. The same scattering lengths are
also measured using ~90x10^6 K±→π±π0π0 decays where a cusp structure in
the Dalitz plot has been observed for the first time.