title: Half-life systematics across the N=126 shell closure: role of first-forbidden transitions in the β decay of heavy neutron-rich nuclei.
abstract: This Letter reports on a systematic study of β-decay half-lives of neutron-rich nuclei around doubly magic (208)Pb. The lifetimes of the 126-neutron shell isotone (204)Pt and the neighboring (200-202)Ir, (203)Pt, (204)Au are presented together with other 19 half-lives measured during the "stopped beam" campaign of the rare isotope investigations at GSI collaboration. The results constrain the main nuclear theories used in calculations of r-process nucleosynthesis. Predictions based on a statistical macroscopic description of the first-forbidden β strength reveal significant deviations for most of the nuclei with N<126. In contrast, theories including a fully microscopic treatment of allowed and first-forbidden transitions reproduce more satisfactorily the trend in the measured half-lives for the nuclei in this region, where the r-process pathway passes through during β decay back to stability.
authors: Universidade de Santiago de Compostela, E-15782 Santiago de Compostela, Spain.
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authors: Morales
authors: Universidade de Santiago de Compostela, E-15782 Santiago de Compostela, Spain.
authors: J
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authors: Benlliure
authors: Universidade de Santiago de Compostela, E-15782 Santiago de Compostela, Spain.
authors: T
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authors: Kurtukián-Nieto
authors: GSI, Planckstrasse 1, D-64291 Darmstadt, Germany.
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authors: Universidade de Santiago de Compostela, E-15782 Santiago de Compostela, Spain.
authors: S
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authors: Department of Physics, University of Surrey, Guildford GU2 7XH, United Kingdom and National Physical Laboratory, Teddington, Middlesex TW11 0LW, United Kingdom.
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authors: Regan
authors: Department of Physics, University of Surrey, Guildford GU2 7XH, United Kingdom.
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authors: GSI, Planckstrasse 1, D-64291 Darmstadt, Germany.
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authors: Department of Physics, University of Surrey, Guildford GU2 7XH, United Kingdom.
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authors: GSI, Planckstrasse 1, D-64291 Darmstadt, Germany and IFAC, New Delhi, India.
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authors: Kumar
authors: Universidade de Santiago de Compostela, E-15782 Santiago de Compostela, Spain.
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authors: Casarejos
authors: Department of Physics, University of Surrey, Guildford GU2 7XH, United Kingdom.
authors: N
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authors: Al-Dahan
authors: IFIC, CSIC-Universidad de Valencia, E-46071 Valencia, Spain and Institute of Nuclear Research of the Hungarian Academy of Sciences, Debrecen H-4001, Hungary.
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authors: Algora
authors: Department of Physics, University of Surrey, Guildford GU2 7XH, United Kingdom.
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authors: Alkhomashi
authors: Universidade de Santiago de Compostela, E-15782 Santiago de Compostela, Spain.
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authors: Álvarez-Pol
authors: INFN, Università degli Studi di Milano, I-20133 Milano, Italy.
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authors: Benzoni
authors: IKP, University of Cologne, D-50937 Cologne, Germany.
authors: A
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authors: Blazhev
authors: GSI, Planckstrasse 1, D-64291 Darmstadt, Germany.
authors: P
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authors: Boutachkov
authors: School of Computing, Engineering and Mathematics, University of Brighton, Brighton BN2 4GJ, United Kingdom.
authors: A M
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authors: Bruce
authors: GSI, Planckstrasse 1, D-64291 Darmstadt, Germany.
authors: L S
authors: LS
authors: Cáceres
authors: Department of Physics, University of Surrey, Guildford GU2 7XH, United Kingdom.
authors: I J
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authors: Cullen
authors: School of Computing, Engineering and Mathematics, University of Brighton, Brighton BN2 4GJ, United Kingdom.
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authors: Denis Bacelar
authors: GSI, Planckstrasse 1, D-64291 Darmstadt, Germany.
authors: P
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authors: Doornenbal
authors: Universidade de Santiago de Compostela, E-15782 Santiago de Compostela, Spain.
authors: M E
authors: ME
authors: Estévez-Aguado
authors: Department of Physics, University of Surrey, Guildford GU2 7XH, United Kingdom.
authors: G
authors: G
authors: Farrelly
authors: Department of Physics, Osaka University, 560-0043 Osaka, Japan.
authors: Y
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authors: Fujita
authors: Department of Physics, University of Surrey, Guildford GU2 7XH, United Kingdom.
authors: A B
authors: AB
authors: Garnsworthy
authors: Department of Physics, University of Surrey, Guildford GU2 7XH, United Kingdom.
authors: W
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authors: Gelletly
authors: GSI, Planckstrasse 1, D-64291 Darmstadt, Germany.
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authors: Gerl
authors: The Henryk Niewodniczànski Institute of Nuclear Physics, PL-31-342 Kraków, Poland.
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authors: Grebosz
authors: Department of Physics, Lund University, S-22100 Lund, Sweden.
authors: R
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authors: Hoischen
authors: GSI, Planckstrasse 1, D-64291 Darmstadt, Germany.
authors: I
authors: I
authors: Kojouharov
authors: GSI, Planckstrasse 1, D-64291 Darmstadt, Germany.
authors: N
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authors: Kurz
authors: School of Computing, Engineering and Mathematics, University of Brighton, Brighton BN2 4GJ, United Kingdom.
authors: S
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authors: Lalkovski
authors: School of Physics and Astronomy, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom.
authors: Z
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authors: Liu
authors: Horia Hulubei National Institute of Physics and Nuclear Engineering (IFIN-HH), RO-077125 Bucharest-Magurele, Romania.
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authors: Mihai
authors: IFIC, CSIC-Universidad de Valencia, E-46071 Valencia, Spain.
authors: F
authors: F
authors: Molina
authors: IKP, University of Cologne, D-50937 Cologne, Germany.
authors: D
authors: D
authors: Mücher
authors: IFIC, CSIC-Universidad de Valencia, E-46071 Valencia, Spain.
authors: B
authors: B
authors: Rubio
authors: GSI, Planckstrasse 1, D-64291 Darmstadt, Germany.
authors: H
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authors: Shaffner
authors: Department of Physics, University of Surrey, Guildford GU2 7XH, United Kingdom.
authors: S J
authors: SJ
authors: Steer
authors: Research Center for Nuclear Physics (RCNP), Osaka University, 567-0047 Osaka, Japan.
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authors: GSI, Planckstrasse 1, D-64291 Darmstadt, Germany.
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authors: Tashenov
authors: INFN-Laboratori Nazionali di Legnaro, I-35020 Legnaro, Italy.
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authors: Department of Physics, University of Surrey, Guildford GU2 7XH, United Kingdom.
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authors: Walker
authors: GSI, Planckstrasse 1, D-64291 Darmstadt, Germany.
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authors: Wollersheim
authors: School of Physics and Astronomy, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom.
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