Precision measurement of ππ scattering lengths at the NA48/2 experiment

The NA48/2 experiment at CERN [1] collected ∼18⋅109 charged kaon decays during the years 2003/4. Along with the primary goals of the collaboration, i.e. the measurement of the CP-violating asymmetry in the K±→π±π+π− and K±→π±π0π0 decays thanks to the simultaneous collection of K+ and K− events, the collected data allowed to perform many other interesting analyses. In this paper two independent measurements of ππ scattering lengths will be reviewed, using NA48/2 data from the K±→e±νπ+π− decay and from the cusp effect in K±→π±π+π− respectively.