β-Decay Half-Lives of 110 Neutron-Rich Nuclei across the N=82 Shell Gap: Implications for the Mechanism and Universality of the Astrophysical r Process.
نویسندگان
چکیده
The β-decay half-lives of 110 neutron-rich isotopes of the elements from _{37}Rb to _{50}Sn were measured at the Radioactive Isotope Beam Factory. The 40 new half-lives follow robust systematics and highlight the persistence of shell effects. The new data have direct implications for r-process calculations and reinforce the notion that the second (A≈130) and the rare-earth-element (A≈160) abundance peaks may result from the freeze-out of an (n,γ)⇄(γ,n) equilibrium. In such an equilibrium, the new half-lives are important factors determining the abundance of rare-earth elements, and allow for a more reliable discussion of the r process universality. It is anticipated that universality may not extend to the elements Sn, Sb, I, and Cs, making the detection of these elements in metal-poor stars of the utmost importance to determine the exact conditions of individual r-process events.
منابع مشابه
Shell - model half - lives for r - process N = 82 nuclei
We have performed shell-model calculations of the half-lives and neutron-branching probabilities of the r-process waiting point nuclei at the magic neutron number N = 82. These new calculations use a larger model space than previous shell model studies and an improved residual interaction which is adjusted to recent spectroscopic data around A = 130. Our shell-model results give a good account ...
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متن کاملTitle β - Decay Half - Lives of 110 Neutron - Rich Nuclei across the N = 82 Shell Gap : Implications for
Author(s) Lorusso, G; Nishimura, S; Xu, Z; Jungclaus, A; Shimizu, Y; Simpson, GS; Söderström, PA; Watanabe, H; Browne, F; Doornenbal, P; Gey, G; Jung, HS; Meyer, B; Sumikama, T; Taprogge, J; Vajta, Z; Wu, J; Baba, H; Benzoni, G; Chae, KY; Crespi, FCL; Fukuda, N; Gernhäuser, R; Inabe, N; Isobe, T; Kajino, T; Kameda, D; Kim, GD; Kim, YK; Kojouharov, I; Kondev, FG; Kubo, T; Kurz, N; Kwon, YK; Lane...
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ورودعنوان ژورنال:
- Physical review letters
دوره 114 19 شماره
صفحات -
تاریخ انتشار 2015