Elsevier

Nuclear Physics A

Volume 327, Issue 1, 17 September 1979, Pages 172-192
Nuclear Physics A

The Jπ = 3 doublet at Ex = 6241 keV in 18F: Isospin mixing

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Abstract

The resonance previously observed at Ex = 6241 keV in the reactions 17O(p, γ)18F and 14N(α, γ)18F has been found to be a closely separated doublet (ΔEx = 2.09±0.04 keV). Resonance strengths in 17O(p, γ)18F, 17O(p, α)14N and 14N(α, γ)18 have been measured and partial widths for the resonance states have been obtained. The doublet was further investigated by means of the 4He(14N, α)14N reaction using the differentially pumped gas target at CRNL. Analysis of these data using R-matrix theory yielded Jπ = 3 for both states and more precise values of the α-particle widths (Γα(lower) = 133 ±4 eV; Γα(upper) = 137 ±4 eV). The reduced α-particle widths and the E1 and M1 transition strengths indicate that the doublet arises from the nearly complete mixing of T = 0 and T = 1 eigenstates which in the absence of an isospin breaking interaction would have been separated by less than 40 eV. The α-particle scattering experiments included the Jπ = 1+ resonance at Ex = 6257 keV and yielded the new values of Γα = 580±12 eV and Γp = 25+35−25 eV.

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  • Cited by (5)

    • Energy levels of light nuclei A = 18-19

      1995, Nuclear Physics, Section A

    Partially supported by NRC Canada.

    Present address: Teklogix Ltd., 1260 Fewster Dr., Mississauga, Ontario.

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