High Precision Measurement of the Superallowed 0^+ to 0^+ Beta Decay of ^{22}Mg

Abstract

The half-life, 3.8755(12) s, and superallowed branching ratio, 0.5315(12), for ^{22}Mg beta-decay have been measured with high precision. The latter depended on gamma-ray intensities being measured with an HPGe detector calibrated for relative efficiencies to an unprecedented 0.15%. Previous precise measurements of 0^+ to 0^+ transitions have been restricted to the nine that populate stable daughter nuclei. No more such cases exist, and any improvement in a critical CKM unitarity test must depend on precise measurements of more exotic nuclei. With this branching-ratio measurement, we show those to be possible for T_z = -1 parents. We obtain a corrected Ft-value of 3071(9) s, in good agreement with expectations.

4 pages, 2 figures, revtex4

References in corpus (2)

• Calculated corrections to superallowed Fermi beta decay: New evaluation of the nuclear-structure-dependent terms
• The 21Na(p,gamma)22Mg Reaction and Oxygen-Neon Novae

Cited by in corpus (12)

• Superallowed 0+ to 0+ nuclear beta decays: A new survey with precision tests of the conserved vector current hypothesis and the standard model
• Superallowed 0+ --> 0+ nuclear beta decays: 2014 critical survey, with precise results for Vud and CKM unitarity
• Superallowed nuclear beta decays: A critical survey with tests of CVC and the standard model
• Q-value of the superallowed beta decay of Ga-62
• Quark Mixing, CKM Unitarity
• Precise Half-Life Measurement of the Superallowed Beta+ Emitter 26Si
• Beta-decay study of $T_z=-2$ proton-rich nucleus ${}^{20}$Mg
• The use of Geant4 for simulations of a plastic beta-detector and its application to efficiency calibration
• Proton-decaying states in 22Mg and the nucleosynthesis of 22Na in novae
• Half-Life of ${}^{14}$O
• The beta-gamma decay of 21Na
• High-Precision Half-life Measurement for the Superallowed Fermi ${\beta }^{+}$ Emitter ${}^{22}$Mg