Quantum Coherence and CPT-Symmetry Tests in Entangled Neutral Kaons at KLOE

We report on the latest results on quantum-coherence and CPT-symmetry tests from 1.7 fb⁻¹ integrated luminosity collected at the Frascati ϕ-factory DAΦNE. A data sample of 1.7 × 10⁹ decays in the K_SK_L → π⁺π⁻π⁺π⁻ channel allows for precision tests of destructive quantum interference preventing entangled kaon decay at the same proper time difference Δt from production. We reconstruct decoherence and CPT-violation parameters from several phenomenological models with improved accuracy and inference techniques from previous analyses. We find no evidence of new physics and set the most stringent limits on such models to date. For some parameters we reach sensitivity to the quantum-gravity scale.