We have measured the half-life of the superallowed 0+ -to- 0+ beta+ emitter 26Si to be 2245.3(7) ms. We used pure sources of 26Si and employed a high-efficiency gas counter, which was sensitive to positrons from both this nuclide and its daughter 26mAl. The data were analyzed as a linked parent-daughter decay. To contribute meaningfully to any test of the unitarity of the Cabibbo-Kobayashi-Maskawa (CKM) matrix, the ft value of a superallowed transition must be determined to a precision of 0.1% or better. With a precision of 0.03% the present result is more than sufficient to be compatable with that requirement. Only the branching ratio now remains to be measured precisely before a +/-0.1% ft value can be obtained for the superallowed transition from 26Si.
@article{arxiv.1008.2940,
title = {Precise Half-Life Measurement of the Superallowed Beta+ Emitter 26Si},
author = {V. E. Iacob and J. C. Hardy and A. Banu and L. Chen and V. V. Golovko and J. Goodwin and V. Horvat and N. Nica and H. I. Park and L. Trache and R. E. Tribble},
journal= {arXiv preprint arXiv:1008.2940},
year = {2014}
}