Measurement of the 2+→0+ ground-state transition in the β decay of F 20

Summary, in English

We report the first detection of the second-forbidden, nonunique, 2+→0+, ground-state transition in the β decay of F20. A low-energy, mass-separated F+20 beam produced at the IGISOL facility in Jyväskylä, Finland, was implanted in a thin carbon foil and the β spectrum measured using a magnetic transporter and a plastic-scintillator detector. The β-decay branching ratio inferred from the measurement is bβ=[0.41±0.08(stat)±0.07(sys)]×10-5 corresponding to logft=10.89(11), making this one of the strongest second-forbidden, nonunique β 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 Ne20 is now known to within better than 25% at the relevant temperatures and densities.

• Author: O. S. Kirsebom; M. Hukkanen; A. Kankainen; W. H. Trzaska; D. F. Strömberg; G. Martínez-Pinedo; K. Andersen; E. Bodewits; B. A. Brown; L. Canete; J. Cederkäll; T. Enqvist; T. Eronen; H. O.U. Fynbo; S. Geldhof; R. De Groote; D. G. Jenkins; A. Jokinen; P. Joshi; A. Khanam; J. Kostensalo; P. Kuusiniemi; K. Langanke; I. Moore; M. Munch; D. A. Nesterenko; J. D. Ovejas; H. Penttilä; I. Pohjalainen; M. Reponen; S. Rinta-Antila; K. Riisager; A. De Roubin; P. Schotanus; P. C. Srivastava; J. Suhonen; J. A. Swartz; O. Tengblad; M. Vilen; S. Vínals; J. Aÿstö
• Department/s: Nuclear physics
• Publishing year: 2019-12-24
• Language: English
• Publication/Series: Physical Review C
• Volume: 100
• Issue: 6
• Links: http://dx.doi.org/10.1103/PhysRevC.100.065805
• Document type: Journal article
• Publisher: American Physical Society
• Topic: Subatomic Physics
• Status: Published
• ISBN/ISSN/Other: ISSN: 2469-9985