Weak-Interaction Theories ofCPNonconservation Applied to Hyperon Nonleptonic Decay

Abstract

Possible $\mathrm{CP}$ violation in hyperon nonleptonic decay is investigated in the framework of several current-current weak-interaction theories which have recently been proposed. Of those studied, only the neutral-current models of Das and Oakes lead to unambiguous results. The Das model is extraordinary in that it predicts a maximal $\mathrm{CP}$ violation in the $\ensuremath{\Sigma}_{+}^{}{}_{}{}^{+}$ decay mode which, unfortunately, the final-state interactions conspire to imitate even if $\mathrm{CP}$ is conserved. This same model suggests a $\mathrm{CP}$-violating effect in the $\ensuremath{\Sigma}_{\ensuremath{-}}^{}{}_{}{}^{\ensuremath{-}}$ mode, which is roughly a 2\ifmmode^\circ\else\textdegree\fi{} departure from the final-state-interaction correction of 7\ifmmode^\circ\else\textdegree\fi{} to $\ensuremath{\Delta}$.