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arXiv · 1203.5281

Impact of New beta-decay Half-lives on r-process Nucleosynthesis

Nobuya Nishimura·Toshitaka Kajino·Grant J. Mathews·Shunji Nishimura·Toshio Suzuki
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Abstract

We investigate the effects of newly measured beta-decay half-lives on r-process nucleosynthesis. These new rates were determined by recent experiments at the radioactive isotope beam factory facility in the RIKEN Nishina Center. We adopt an r-process nucleosynthesis environment based on a magnetohydrodynamic supernova explosion model that includes strong magnetic fields and rapid rotation of the progenitor. A number of the new beta-decay rates are for nuclei on or near the r-process path, and hence they affect the nucleosynthesis yields and time scale of the r-process. The main effect of the newly measured beta-decay half-lives is an enhancement in the calculated abundance of isotopes with mass number A = 110 -- 120 relative to calculated abundances based upon beta-decay rates estimated with the finite-range droplet mass model. This effect slightly alleviates, but does not fully explain, the tendency of r-process models to underproduce isotopes with A = 110 -- 120 compared to the solar-system r-process abundances.

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Nobuya Nishimura, Toshitaka Kajino, Grant J. Mathews, Shunji Nishimura, Toshio Suzuki. 2012-03-23. Impact of New beta-decay Half-lives on r-process Nucleosynthesis. https://doi.org/10.1103/physrevc.85.048801

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