High precision measurement of the superallowed 0+ --> 0+ beta decay of 22Mg. Academic Article uri icon


  • The half-life, 3.8755(12) s, and superallowed branching ratio, 0.5315(12), for 22Mg 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+ --> 0+ transitions have been restricted to the nine that populate stable daughter nuclei. No more such cases exist, and any improvement in a critical Cabibbo-Kobayashi-Maskawa 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.

published proceedings

  • Phys Rev Lett

author list (cited authors)

  • Hardy, J. C., Iacob, V. E., Sanchez-Vega, M., Neilson, R. G., Azhari, A., Gagliardi, C. A., ... Tribble, R. E.

citation count

  • 49

complete list of authors

  • Hardy, JC||Iacob, VE||Sanchez-Vega, M||Neilson, RG||Azhari, A||Gagliardi, CA||Mayes, VE||Tang, X||Trache, L||Tribble, RE

publication date

  • August 2003