Suchergebnisse

22 pags., 8 figs., 4 tabs., 1 app. ; A dedicated spectroscopic study of the β decay of Cd127 was conducted at the IGISOL facility at the University of Jyväskylä. Following high-resolution mass separation in a Penning trap, β-γ-γ coincidences were used to considerably extend the decay scheme of In127. The β-decaying 3/2+ and 11/2- states in Cd127 have been identified with the Cd127 ground state and the 283-keV isomer. Their respective half-lives have been measured to 0.45(812)s and 0.36(4) s. The experimentally observed β feeding to excited states of In127 and the decay scheme of In127 are discussed in conjunction with large-scale shell-model calculations. ; The authors thank the accelerator staff at the University of Jyväskylä. This work is supported by the European Union's Horizon 2020 research and innovation programme Grant No. 654002 (ENSAR2), the Swedish Research Council (VR 2013- 4271), the Knut and Alice Wallenberg foundation (KAW 2015.0021), the Academy of Finland under the Finnish Centre of Excellence Program (Nuclear and Accelerator Based Physics Research at JYFL 2012-2017), and the Spanish Ministerio de Economía y Competitividad under Contract No. FPA2017-84756-C4-2-P. The support from the Academy of Finland under Grants No. 275389, No. 284516, No. 312544, and No. 295207 is acknowledged. A.K. and L.C. acknowledge the funding from the European Union's Horizon 2020 research and innovation program under Grant No. 771036 (ERC CoG MAIDEN). U.F. acknowledges support from the Birgit and Hellmuth Hertz Foundation of the Royal Physiographic Society in Lund.

12 pags., 16 figs., 4 tabs. ; We report the first detection of the second-forbidden, nonunique, 2+ → 0+, ground-state transition in the β decay of 20F. A low-energy, mass-separated 20F+ 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 plasticscintillator detector. The β-decay branching ratio inferred from the measurement is bβ = [0.41 ± 0.08(stat) ± 0.07(sys)] × 10−5 corresponding to log f t = 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 20Ne is now known to within better than 25% at the relevant temperatures and densities ; This work has been supported by the Academy of Finland under the Finnish Centre of Excellence Programme (Nuclear and Accelerator Based Physics Research at JYFL 2012-2017) and Academy of Finland Grants No. 275389, No. 284516, No. 295207, and No. 312544. D.F.S. and G.M.-P. acknowledge the support of the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation)-Projektnummer 279384907-SFB 1245 "Nuclei: From Fundamental Interactions to Structure and Stars"; and the ChETEC COST action (CA16117), funded by COST (European Cooperation in Science and Technology). This project has been partly supported by the Spanish Ministry MINECO through the grant FPA2015-64969-P and has received funding from the European Union's Horizon 2020 research and innovation programme under Grant Agreement No. 654002 (ENSAR2). O.S.K. acknowledges support from the Villum Foundation through Project No. 10117. P.C.S. acknowledges the support from the Faculty Initiation Grant (FIG) provided by IIT Roorkee. A.K. and M.H. acknowledge the support from the European Union's Horizon 2020 research and innovation program under Grant Agreement No. 771036 (ERC CoG MAIDEN). B.A.B. acknowledges the support from NSF Grant PHY-1811855.