Q_EC values of the Superallowed beta Emitters 50Mn and 54Co

Abstract

Using a new fast cleaning procedure to prepare isomerically pure ion samples, we have measured the beta-decay Q_EC values of the superallowed beta-emitters 50Mn and 54Co to be 7634.48(7) keV and 8244.54(10) keV, respectively, results which differ significantly from the previously accepted values. The corrected Ft values derived from our results strongly support new isospin-symmetry-breaking corrections that lead to a higher value of the up-down quark mixing element, Vud, and improved confirmation of the unitarity of the Cabibbo-Kobayashi-Maskawa matrix.

arXiv comment4 pages, 5 figures, 1 table, submitted to Phys. Rev. Lett

References in corpus (9)

• The Cosmological Parameters 2006
• Big-Bang nucleosynthesis (Particle Data Group mini-review)
• An improved calculation of the isospin-symmetry-breaking corrections to superallowed Fermi beta decay
• Superallowed nuclear beta decays: A critical survey with tests of CVC and the standard model
• The Ramsey method in high-precision mass spectrometry with Penning traps: Experimental results
• Q value of the 100Mo Double-Beta Decay
• Calculated corrections to superallowed Fermi beta decay: New evaluation of the nuclear-structure-dependent terms
• New limit on fundamental weak-interaction parameters from superallowed beta decay
• 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

Cited by in corpus (16)

• Superallowed 0+ to 0+ nuclear beta decays: A new survey with precision tests of the conserved vector current hypothesis and the standard model
• Superallowed 0+ --> 0+ nuclear beta decays: 2014 critical survey, with precise results for Vud and CKM unitarity
• Mass measurements in the vicinity of the rp-process and the nu p-process paths with JYFLTRAP and SHIPTRAP
• Alpha_s(M_Z) from hadronic tau decays
• Collectivity-induced quenching of signatures for shell closures
• Error analysis of nuclear mass fits
• Mass Measurements and Implications for the Energy of the High-Spin Isomer in 94Ag
• Mass measurements in the vicinity of the doubly-magic waiting point 56Ni
• Small violations of unitarity, the phase in Bs mixing and visible t->cZ decays at the LHC
• First direct determination of the superallowed $\beta$-decay $Q_{EC}$-value for ${}^{14}$O
• A Mixed Tau-Electroproduction Sum Rule for V_us
• Status of the Hadronic tau Decay Determination of |V_{us}|
• Pulsed extraction of ionization from helium buffer gas
• The measurement and interpretation of superallowed 0+ to 0+ nuclear beta decay
• Q-Value for the Fermi Beta-Decay of 46V
• A Review of the Magnitudes of the CKM Matrix Elements