Theory of Parity-Violating Nonleptonic Decay

Abstract

The simplest way of explaining the result $A({\ensuremath{\Sigma}}^{+}|n{\ensuremath{\pi}}^{+})=0$ is to assume an effective parity-violating Hamiltonian of the form ${(\overline{B}\ifmmode\times\else\texttimes\fi{}B)}_{(8)}\ifmmode\times\else\texttimes\fi{}\ensuremath{\pi}$. With no further assumptions, this Hamiltonian predicts two sum rules which are closely related to the Lee-Sugawara triangle, and it imposes an isotopic-spin selection rule $\ensuremath{\Delta}Tl\frac{5}{2}$. The proposed coupling scheme is a consequence of several dynamical models, and the $\ensuremath{\Delta}Tl\frac{5}{2}$ rule is consistent with the data on $K\ensuremath{\rightarrow}2\ensuremath{\pi}$.