Examining CP Symmetry in Strange Baryon Decays

Abstract

Non-conservation of CP symmetry can manisfest itself in non-leptonic hyperon decays as a difference in the decay parameter between the strange-baryon decay and its charge conjugate. By comparing the decay distribution in the $Λ$ helicity frame for the decay sequence $Ξ^{-} \to Λπ^{-}$, $Λ\to p π^{-}$ with that of $\barΞ^{+}$ decay, E756 at Fermilab did not observe any CP-odd effect at the $10^{-2}$ level. The status of a follow-up experiment, HyperCP (FNAL E871), to search for CP violation in charged $Ξ-Λ$ decay with a sensitivity of $10^{-4}$ is also presented.