The beta decay of 38Ca: Sensitive test of isospin symmetry-breaking corrections from mirror superallowed 0+-to-0+ transitions

Abstract

We report the first branching-ratio measurement of the superallowed 0+-to-0+ beta transition from 38Ca. The result, 0.7728(16), leads to an ft value of 3062.3(68)s with a relative precision of +/-0.2%. This makes possible a high-precision comparison of the ft values for the mirror superallowed transitions, 38Ca-to-38mK and 38mK-to-38Ar, which sensitively tests the isospin symmetry-breaking corrections required to extract Vud, the up-down quark-mixing element of the Cabibbo-Kobayashi-Maskawa (CKM) matrix, from superallowed beta decay. The result supports the corrections currently used, and points the way to even tighter constraints on CKM unitarity.

5 pages, 3 figures

References in corpus (3)

• Superallowed 0+ to 0+ nuclear beta decays: A new survey with precision tests of the conserved vector current hypothesis and the standard model
• An improved calculation of the isospin-symmetry-breaking corrections to superallowed Fermi beta decay
• The use of Geant4 for simulations of a plastic beta-detector and its application to efficiency calibration

Cited by in corpus (10)

• Superallowed 0+ --> 0+ nuclear beta decays: 2014 critical survey, with precise results for Vud and CKM unitarity
• No-core configuration-interaction model for the isospin- and angular-momentum-projected states
• Data-driven reevaluation of $ft$-values in superallowed $\beta$ decays
• Nuclear charge radius of ${}^{26m}$Al and its implication for V${}_{ud}$ in the quark-mixing matrix
• The measurement and interpretation of superallowed 0+ to 0+ nuclear beta decay
• Radial overlap correction to superallowed $0^{+}\to 0^{+}$ nuclear $\beta$ decays using the shell model with Hartree-Fock radial wave functions
• Isospin effects in N~Z nuclei in extended Density Functional Theory
• Theoretical corrections and world data for the superallowed ft values in the beta decays of 42Ti, 46Cr, 50Fe and 54Ni
• Exploiting dissipative reactions to perform in-beam $\gamma$-ray spectroscopy of the neutron-deficient isotopes \nuc{38,39}{Ca}
• High-Precision Half-life Measurement for the Superallowed Fermi ${\beta }^{+}$ Emitter ${}^{22}$Mg