Precision Branching Ratio Measurement for the Superallowed {beta}{sup +} Emitter {sup 62}Ga and Isospin-Symmetry-Breaking Corrections in A{>=}62 Nuclei

A high-precision branching ratio measurement for the superallowed {beta}{sup +} decay of {sup 62}Ga was performed at the Isotope Separator and Accelerator radioactive ion beam facility. Nineteen {gamma} rays emitted following {beta}{sup +} decay of {sup 62}Ga were identified, establishing the dominant superallowed branching ratio to be (99.861{+-}0.011)%. Combined with recent half-life and Q-value measurements, this branching ratio yields a superallowed ft value of 3075.6{+-}1.4 s for {sup 62}Ga decay. These results demonstrate the feasibility of high-precision superallowed branching ratio measurements in the A{>=}62 mass region and provide the first stringent tests of the large isospin-symmetry-breaking effects predicted for these decays.