Branching ratios in the {beta} decays of {sup 12}N and {sup 12}B

Absolute branching ratios to unbound states in {sup 12}C populated in the {beta} decays of {sup 12}N and {sup 12}B are reported. Clean sources of {sup 12}N and {sup 12}B were obtained using the isotope separation on-line (ISOL) method. The relative branching ratios to the different populated states were extracted using single-alpha as well as complete kinematics triple-alpha spectra. These two largely independent methods give consistent results. Absolute normalization is achieved via the precisely known absolute branching ratio to the bound 4.44 MeV state in {sup 12}C. The extracted branching ratios to the unbound states are a factor of three more precise than previous measurements. Branching ratios in the decay of {sup 20}Na are also extracted and used to check the results.