Neutral kaons provide one of the most sensitive systems to test quantum mechanics and CPT violation.In the first part of this report I review the results on CPT violation searches in the kaon system from the CPLEAR, KLOE and KTeV experiments.In the second part, I report tests of quantum coherence related to CPT violation, performed at CPLEAR and KLOE by studying the time evolution of the kaon system.The results show no deviations from the expectations of quantum mechanics and CPT symmetry, and the accuracy reaches the interesting region of the Planck's scale.
Neutral kaons produced in the correlated pairs at the DAΦNE
ϕ -factory offer unique possibilities to perform fundamental tests of CPT invariance, as well as of the basic principles of quantum mechanics. The analysis of the data collected by the KLOE experiment allows to improve results on several parameters describing CPT violation and decoherence, and to measure the regeneration cross section on the beam pipe materials.