Elucidation of the rare-earth element peak around A = 160 in the r-process nucleosynthesis

2014 Fiscal Year Final Research Report

• Project/Area Number: 24740188
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: The Institute of Physical and Chemical Research
• Principal Investigator: WATANABE Hiroshi 独立行政法人理化学研究所, 仁科加速器研究センター, 客員研究員 (60333316)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 国際共同研究 / 元素合成 / 中性子過剰核 / ベータ崩壊 / 半減期 / 核異性体 / RIビームファクトリー

Outline of Final Research Achievements

Nearly half of elements heavier than iron in the universe are considered to be synthesized via a rapid-neutron capture (r) process, which takes place in explosive astrophysical sites like supernovae and/or neutron-star mergers. In the present work, we have measured beta-decay half-lives, decay schemes, and isomeric states in a wide range of neutron-rich isotopes relevant to the r-process nucleosynthesis, particularly focusing on deformed nuclei around mass 160 which should affect the formation of the so-called rare-earth element peak. Those spectroscopic information, in combination with the new data obtained as well for neutron-rich isotopes in the vicinity of the doubly-magic nuclei 78Ni and 132Sn, are expected to serve for improvement of the astrophysical simulations of r-process.

Free Research Field

原子核物理学