Measurement of CP,T and CPT violation parameters in the Neutral Kaon system at CPLEAR

The CPLEAR experiment at CERN measures the time dependent decay rate asymmetries of initially pure K0 and K 0 states to study CP,T and CPT symmetries in the neutral kaon system. The latest results on η+−, Δm and x are reported, as well as direct tests of T violation and CPT violation in K0- K 0 oscillations. Our results are consistent with CPT invariance and allow for an improved limit on the K0- K 0 mass difference. Further, a possible loss of quantum coherence of the neutral kaon system has been tested to a level near the Planck scale.