Direct tests of T, CP, CPT symmetries in transitions of neutral K mesons with the KLOE experiment

A data sample of 1.7 fb -1 has been analyzed by the KLOE experiment at DAΦNE to study the distribution of the difference in the kaon decay times ∆t, of φ → K S K L → π + π -π ± e ∓ ν and φ → K S K L → π ± e ∓ ν π 0 π 0 π 0 .Tests of T, CP and CPT symmetries in the neutral kaon system are performed by direct comparison of the probabilities of a kaon transition process and the symmetry-conjugate transition.The exchange of in and out states required for genuine T and CPT tests is fulfilled exploiting the entanglement of kaon pairs produced at the φ-factory.We were able, by the comparison of the measured ∆t distributions in the asymptotic region ∆t τ S , to directly test for the first time T and CPT symmetries in kaon transitions with a few percent precision and to observe CP violation in transitions from CP odd eigenstates to flavour eigenstates, K 0 and K 0 .