Measurement of the 2(+) -> 0(+) ground-state transition in the beta decay of F-20

O. S. Kirsebom*, M. Hukkanen, Anu Kankainen, W. H. Trzaska, D. F. Stroemberg, G. Martinez-Pined, K. Andersen, E. Bodewits, B. A. Brown, L. Canete, J. Cederkall, T. Enqvist, Tommi Eronen, H. O. U. Fynbo, S. Geldhof, R. de Groote, D. G. Jenkins, Ari Jokinen, P. Joshi, A. KhanamJoel Kostensalo, Pasi Kuusiniemi, K. Langanke, T.J.T. Moore, M. Munch, D. A. Nesterenko, J. D. Ovejas, H. Penalla, Tapio Pohjalainen, M. Reponen, S. Rinta-Antila, K. Riisager, A. de Roubin, P. Schotanus, P. C. Srivastava, Jouni Suhonen, J. A. Swartz, O. Tengblad, M. Vilen, S. Vinals, J. Aysto

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

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We report the first detection of the second-forbidden, nonunique, 2(+) -> 0(+), ground-state transition in the beta decay of F-20. A low-energy, mass-separated F-20(+) beam produced at the IGISOL facility in Jyvaskyla, Finland, was implanted in a thin carbon foil and the beta spectrum measured using a magnetic transporter and a plastic-scintillator detector. The beta-decay branching ratio inferred from the measurement is b(beta) = [0.41 +/- 0.08(stat) +/- 0.07(sys)] x 10(-5) corresponding to log ft = 10.89(11), making this one of the strongest second-forbidden, nonunique beta transitions ever measured. The experimental result is supported by shell-model calculations and has significant implications for the final evolution of stars that develop degenerate oxygen-neon cores. Using the new experimental data, we argue that the astrophysical electron-capture rate on Ne-20 is now known to within better than 25% at the relevant temperatures and densities.

Original languageEnglish
Article number065805
Pages (from-to)1-12
Number of pages12
Issue number6
Publication statusPublished - 24 Dec 2019
MoE publication typeA1 Journal article-refereed



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