Parity Nonconservation in Nuclei

The influence of the known weak interactions on the parity impurity of nuclear states is discussed. Derivation of a parity nonconserving interaction rests on the assumption of a current-current hypothesis for the weak interactions. Consequently, observation of parity impurity effects would be an important confirmation of this hypothesis. A simple approximate method of treating the nuclear parity impurity is developed and applied in an effort to find experimental situations favorable to observation of effects due to such impurity. Parity-forbidden alpha decay from excited states of light nuclei and certain electromagnetic transitions in the heavy nuclei appear to be promising. Special attention has been paid to the internal conversion electrons from the 123-keV transition in ${\mathrm{Lu}}^{173}$ whose polarization is estimated to be about 0.4%. An effect on polarized neutrons analogous to "optical rotation" is also discussed.