1. Measurement of the 2+→0+ ground-state transition in the β decay of F 20
- Author
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Kirsebom, O. S., Hukkanen, M., Kankainen, A., Trzaska, W. H., Strömberg, D. F., Martínez-Pinedo, G., Andersen, K., Bodewits, E., Brown, B. A., Canete, L., Cederkäll, J., Enqvist, T., Eronen, T., Fynbo, H. O.U., Geldhof, S., De Groote, R., Jenkins, D. G., Jokinen, A., Joshi, P., Khanam, A., Kostensalo, J., Kuusiniemi, P., Langanke, K., Moore, I., Munch, M., Nesterenko, D. A., Ovejas, J. D., Penttilä, H., Pohjalainen, I., Reponen, M., Rinta-Antila, S., Riisager, K., De Roubin, A., Schotanus, P., Srivastava, P. C., Suhonen, J., Swartz, J. A., Tengblad, O., Vilen, M., Vínals, S., Aÿstö, J., Dalhousie University, University of Jyväskylä, GSI Helmholtzzentrum Schwerionenforschung, Aarhus University, SCIONIX Holland BV, Michigan State University, Lund University, University of Oulu, University of York, Department of Applied Physics, Consejo Superior de Investigaciones Cientificas (CSIC), Indian Institute of Technology System, Aalto-yliopisto, and Aalto University
- Subjects
ELEMENTS ,High Energy Physics::Experiment - Abstract
openaire: EC/H2020/654002/EU//ENSAR2 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.
- Published
- 2019