Isospin mixing in the mass $A=6\mathrm{}$ system is examined by measuring the deuteron decay branch of the ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$ (5.36-MeV; $T=1\mathrm{}$) state. The mixing to be expected due to the Mott-Schwinger part of the Coulomb interaction is calculated. The measured spectra do not show any positive evidence for deuteron decay of the ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$ (5.36-MeV; $T=1\mathrm{}$) state. However, the experimental upper limit for possible isospin mixing is still appreciably larger than that expected from the Mott-Schwinger interaction.

• Received 17 April 1973

DOI:https://doi.org/10.1103/PhysRevC.8.881