Q-values of the Superallowed beta-Emitters 26m-Al, 42-Sc and 46-V and their impact on V_ud and the Unitarity of the CKM Matrix
/ Authors
T. Eronen, J. Hardy, V. Elomaa, U. Hager, J. Hakala, A. Jokinen, A. Kankainen, V. Kolhinen, I. Moore, H. Penttilä
and 5 more authors
S. Rahaman, J. Rissanen, A. Saastamoinen, T. Sonoda, J. Äystö
/ Abstract
The beta-decay Q_EC-values of the superallowed beta emitters 26m-Al, 42-Sc and 46-V have been measured with a Penning trap to a relative precision of better than 8x10^-9. Our result for 46-V, 7052.72(31) keV, confirms a recent measurement that differed significantly from the previously accepted reaction-based Q_EC-value. However, our results for 26m-Al and 42-Sc, 4232.83(13) keV and 6426.13(21) keV, are consistent with previous reaction-based values. By eliminating the possibility of a systematic difference between the two techniques, this result demonstrates that no significant shift in the deduced value of V_ud should be anticipated.
Journal: Physical Review Letters