Search for T and CPT violation in the neutral kaon system

The LEAR cooled p̄ beam will be used to produce tagged K⁰, K̄⁰ in equal numbers through the reactions: p̄+p → K⁰+K⁻+π⁺ or p̄+p → K̄^o+K⁺+π⁻ (toal branching ratio 0.42%). The sign of the charged kaon determines whether a K⁰ or K̄⁰ was produced. Since the physical states of the neutral kaon system are the K_L, K_S there will be transitions between K⁰ and K̄⁰ and vice versa. Eventually the neutral kaon will decay. By measuring the charge of electron in the K_e3 decays: K̄⁰ → e⁻+π⁺+ν̄; K⁰ → e⁺+π⁻+ν, one can determine whether the particle which decayed was K⁰ or K̄⁰. By studying the time evolution of the K_e3 decays, where the initial state at t=0 is pure K⁰ or K̄⁰, it is possible to measure the CP violation parameter ε, the CPT violation parameters Δ λ₀, yl and Δ S=−Δ Q parameters xl, x̄l (which can also reflect CPT violation). This experiment would be the first experiment to search directly for T violation in the neutral koan system where CP has been shown to be violated.