Abstract
The -decay half-lives of 110 neutron-rich isotopes of the elements from to 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 -process calculations and reinforce the notion that the second () and the rare-earth-element () abundance peaks may result from the freeze-out of an 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 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 -process events.
- Received 14 October 2014
DOI:https://doi.org/10.1103/PhysRevLett.114.192501
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