Isospin-Forbidden Decay of theO+,T=2State at 15.43 MeV inMg24

Abstract

The sought, but previously unobserved, isospin-forbidden particle-decay modes of a $T=2\mathrm{}$ state in a $T_z=0\mathrm{}$ nucleus have been determined by particle-particle coincidence techniques. Proton decays ($\Delta T=1\mathrm{} or 2$) and strong evidence for $\alpha$-particle decays ($\Delta T=2\mathrm{}$) from the $T=2\mathrm{}$ state of ${}_{}{}^{24}{}_{}{}^{}\mathrm{Mg}$ were observed and show $\Sigma {\Gamma }_{\mathrm{particle}}\gg {\Gamma }_{\gamma }$.