Tests of the standard model from superallowed Fermi β-decay studies: The 74Rb β-decay
Document Type
Conference Proceeding
Publication Date
9-1-2002
Abstract
Precise measurements of the intensities of superallowed Fermi 0+ → 0- β-decays have provided a powerful test of the CVC hypothesis at the level of 3 × 10-4 and also led to a result in disagreement with unitarity for the CKM matrix at the 98% confidence level. It is essential to address possible trivial explanations for the apparent non-unitarity such as uncertainties in the isospin symmetry-breaking corrections. We have carefully studied the 74Rb→74Kr β-decay in order to measure the non-analog β-decay branching to the 0+ state at 508 keV in 74Kr. We have determined that this branching is < 3 × 10-4, far smaller than any published theoretical estimate. We also show that high-precision, complete spectroscopy, measuring the major β-branches to excited 0+ and 1+ states, must be performed if one is to obtain a meaningful branching ratio to the excited 0+ state and concomitantly deal, in a substantial way, with the possibility of β feeding to an array of 1+ states.
Publication Source (Journal or Book title)
European Physical Journal A
First Page
229
Last Page
232
Recommended Citation
Zganjar, E., Piechaczek, A., Ball, G., Bricault, P., D'Auria, J., Hardy, J., Hodgson, D., Iacob, V., Klages, P., Kulp, W., Leslie, J., Lipoglavsek, M., Macdonald, J., Mak, H., Moltz, D., Savard, G., Von Schwarzenberg, J., Svensson, C., Towner, I., & Wood, J. (2002). Tests of the standard model from superallowed Fermi β-decay studies: The 74Rb β-decay. European Physical Journal A, 15 (1-2), 229-232. https://doi.org/10.1140/epja/i2001-10259-y