Direct CP Violation in charged kaon decays by the NA48/2 experiment at CERN

The NA48/2 experiment at CERN is performing high precision studies of charged kaon decays, using an upgraded NA48 setup and a novel design for simultaneous unseparated $K^{\pm}$ beams. The main goal is to search for direct CP violation in decays to three pions with a sensitivity at a level of $10^{-4}$ on the asymmetry $A_{g}=(g^{+} - g^{-})/(g^{+} +g^{-})$ where $g$ is the linear slope parameter in the Dalitz plot. The experimental procedure and the main systematic effects are discussed, based on the preliminary analysis of a fraction (less than 50%) of the data recorded. The statistical errors on the $K^{\pm} \to \pi^{+}\pi^{-}\pi^{\pm}$ and $K^{\pm} \to \pi^{0}\pi^{0}\pi^{\pm}$ asymmetries are $2.7 \times 10^{-4}$ and $5 \times 10^{-4}$, respectively. The large amount of charged kaon decays collected allow also precision measurements of several rare decay processes.