O⁺[]O⁺ nuclear β-decay of ⁶²Ga

Abstract

The branching ratio for the β-Decay of ⁶²Ga to the first excited O⁺ state in ⁶²Zn has been measured. It is possible to use this branching ratio to test the theoretical method of calculating the [] component of the charge correction term [], which is used with measured ft balues of O⁺-> O⁺ superallowed Fermi β-decay to determine a value for Gv, the weak vector coupling constant. At present the [] correction creates the largest uncertainty in the calculation of Gv. Knowledge of Gv provides both a test of the Conserved Vector Current theory (CVC) as well as a test of the Standard Model. While results are not conclusive, the branching ratio was determined to be 0.032(11)% compared to the theoretical value of 0.035% calculated using procedures similar to those used when estimating []. The branching of the 0.954 MeV γ-ray transition in ⁶²Zn was calculated to be 0.120(21)%. This is the secondary transition seen in the β-decay to the first excited O⁺ state in ⁶²Zn. This study shows that the decay can be measured and with modest improvements in background reduction and by including a higher range of γ-ray energies, future studies should be unambiguous.