New analysis of {sup 14}O {beta} decay: Branching ratios and conserved vector current consistency

Journal Article · Tue Nov 01 04:00:00 EST 2005 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PhysRevC.72.055501· OSTI ID:20699142

Towner, I S; Hardy, J C ^[1]

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1. Cyclotron Institute, Texas A and M University, College Station, Texas 77843 (United States)

The ground-state Gamow-Teller transition in the decay of {sup 14}O is strongly hindered and the electron spectrum shape deviates markedly from the allowed shape. A reanalysis of the only available data on this spectrum changes the branching ratio assigned to this transition by seven standard deviations: Our new result is (0.54{+-}0.02)%. The Kurie plot data from two earlier publications are also examined, and a revision to their published branching ratios is recommended. The required nuclear matrix elements are calculated with the shell model, and, for the first time, consistency is obtained between the M1 matrix element deduced from the analog {gamma} transition in {sup 14}N and that deduced from the slope in the shape-correction function in the {beta} transition, a requirement of the conserved-vector current hypothesis. This consistency is obtained, however, only if renormalized rather than free-nucleon operators are used in the shell-model calculations. In the mirror decay of {sup 14}C, a similar situation occurs. Consistency among the {sup 14}C lifetime, the slope of the shape-correction function, and the M1 matrix element from {gamma} decay can be achieved only with renormalized operators in the shell-model calculation.

• OSTI ID: 20699142
• Journal Information: Physical Review. C, Nuclear Physics, Journal Name: Physical Review. C, Nuclear Physics Journal Issue: 5 Vol. 72; ISSN 0556-2813; ISSN PRVCAN
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
BETA DECAY
BRANCHING RATIO
CARBON 14
CORRECTIONS
ELECTRON SPECTRA
ENERGY-LEVEL TRANSITIONS
FERMI PLOT
GAMMA DECAY
GAMOW-TELLER RULES
GROUND STATES
LIFETIME
MATRIX ELEMENTS
NITROGEN 14
NUCLEAR MATRIX
OXYGEN 14
SHELL MODELS
VECTOR CURRENTS