The neutral-kaon system constitutes a fantastic and unique laboratory for the study of CPT symmetry and the basic principles of quantum mechanics, and a $\phi$-factory represents a unique opportunity to push forward these studies. The experimental results show no deviation from the expectations of quantum mechanics and CPT symmetry, while the extreme precision of the measure- ments, in some cases, reaches the interesting Planck-scale region. At present the KLOE-2 experiment is collecting data with an upgraded detector with the aim of significantly improving these kinds of experimental tests.
Comment: Presented at the Seventh Meeting on CPT and Lorentz Symmetry, Bloomington, Indiana, June 20-24, 2016