Systematic Studies on the β-decay Half-lives of r-process Nuclei

Zhihong Li,Youbao Wang,Yong Zhou,Ding Nan,Bing Guo,Weiping Liu,Xinyue Li,Yang Sun

doi:10.1051/epjconf/201817804006

Zhihong Li, Youbao Wang + Show 6 more

Open Access

https://doi.org/10.1051/epjconf/201817804006

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Journal: EPJ Web of Conferences	Publication Date: Jan 1, 2018
Citations: 1	License type: CC BY 4.0

Affiliation: China Institute of Atomic Energy

Abstract

Based on the accurate macroscopic-microscopic mass formula and the experimental data of β-decay half-lives of the nuclei with atomic number ranging from 20 to 190, a systematic formula has been proposed to calculate β-decay half-lives of neutron-rich nuclei. The formula is proved to reproduce the experimental β-decay half-lives of neutron-rich nuclei very well, and then is used to study the r-process nucleosynthesis in models of high-entropy mass outflows. The calculated abundances show a good agreement with the solar r-abundances around the third peak and the rare earth mass region.

Highlights

The rapid neutron-capture process (r-process) of stellar nucleosynthesis is believed to explain the production of about half of the nuclides heavier than iron in the universe [1, 2]
We have systematically investigated the variation of β-decay half-lives with the decay energy Q and nucleon number (Z, N) based on the experimental data
The formula is tested for the resent experimental data, and used to predict the β-decay half-lives of some nuclei far from stability including the ones on the possible r-process path

Summary

Introduction

The rapid neutron-capture process (r-process) of stellar nucleosynthesis is believed to explain the production of about half of the nuclides heavier than iron in the universe [1, 2]. A large amount of nuclear data, such as mass, decay and reaction rates, are necessary in the studies of r-process. The β-decay half-lives of a large range of extremely neutron-rich nuclei are one of the most important inputs in the r-process model calculations. We have systematically investigated the variation of β-decay half-lives with the decay energy Q and nucleon number (Z, N) based on the experimental data. A systematic formula has been proposed to calculate the β-decay half-lives of that neutron-rich nuclei after taking into account the shell effects and pairing effects. The formula is tested for the resent experimental data, and used to predict the β-decay half-lives of some nuclei far from stability including the ones on the possible r-process path

Systematic formula for β-decay half-lives

Findings

Summary