Isospin mixing in light nuclei is examined through isospin-forbidden particle decay channels. From data on ($\overrightarrow{\mathrm{p}}$,$p$) isospin-forbidden resonances, isospin-mixing amplitudes are extracted. They show definitively a periodicity of 8 in $A$ for $8<~A<~40$. These results are combined with neutron- and alpha-decay data in an isospin analysis that estimates isovector and isotensor amplitudes and nucleon isobar contributions to isospin mixing.

• Received 4 October 1983

DOI:https://doi.org/10.1103/PhysRevLett.51.2269