应稀有同位素前沿科学中心邀请，北京航空航天大学Toshiaka Kajino教授将于2025年4月14日来校进行学术交流并作报告。

报告题目：Roles of Nuclear Structure and Reactions in Explosive Nucleosynthesis and Cosmic Evolution — Solving the Mystery of Neutrinos and the Origin of Nuclei

报告时间：2025年4月14日（星期一）9:30    

报告地点：兰州大学二分部现物楼214室

欢迎广大师生参加！

【报告摘要】

There is a growing consensus in recent multi-messenger astronomy that the explosions of single massive stars, i.e. supernovae (SNe) and collapsars, dominate the r-element production over the entire history of cosmic evolution, while the neutron-star mergers could contribute only partly in the recent epoch of cosmic history because of long time-delay due to too slow GW radiation [1]. We will, first, discuss when and how these astrophysical sites have contributed to the enrichment of the heavy elements in the universe. We have recently found that the i- and s-processes also could occur in the collapsar nucleosynthesis [2]. These explosive phenomena emit extremely large flux of energetic neutrinos that provide unique nucleosynthetic signals of the neutrino-nucleus interactions at high densities. We will, secondly, discuss the neutrino-flavor oscillations including self-interaction which affect strongly the explosive nucleosynthesis of so-called neutrino-nuclei such as 138La, 180Ta, 92Nb, 98Tc, 11B, 7Li, etc. and also extremely abundant p-nuclei like 92,94Mo and 96,98Ru [3] whose origin have not yet been found uniquely since B2FH in 1957. We here propose a new sensitive nuclear astrophysics method to constrain still unknown neutrino mass hierarchy [4]. Throughout these discussions, we will highlight the critical nuclear physics relevant for the stellar nucleosynthesis at finite temperature [5].

[1] Y. Yamazaki, Z. He, T. Kajino, et al., ApJ 933 (2022), 112.

[2] Z. He, et al. with T. Kajino, ApJ Lett. 966 (2024), L37; PRL (2025),

submitted.

[3] H. Sasaki, Y. Yamazaki, T. Kajino, et al., ApJ 924 (2022), 29; PL B851 (2024), 138581.

[4] X. Yao, Y. Luo, T. Kajino, et al., ApJ 980 (2025) 247; CPC (2025), submitted.

[5] X. Wang, B. Sun, T. Kajino, et al. ApJ (2025), in press.

【报告人简介】

Toshitaka Kajino is a distinguished professor at Beihang University, where he also serves as the Director of the International Research Center for Big-Bang Cosmology and Element Genesis and Chief Scientist of the Peng Huanwu Collaborative Center for Research and Education. He studied at The University of Tokyo from 1975 to 1984, earning his Bachelor’s, Master’s, and Ph.D. degrees. Following his graduation, he joined Tokyo Metropolitan University as an Assistant Professor of Physics. In 1993, he was appointed as a professor at the National Astronomical Observatory of Japan (NAOJ). He also held a concurrent position at The University of Tokyo until 2021. Since 2017, Prof. Kajino has been affiliated with Beihang University. He is internationally recognized for his pioneering research on the origin of the elements in the universe, Big Bang nucleosynthesis, and supernova explosions. He was elected as a Fellow of the American Physical Society (APS) in 2004, and National High-end Foreign Specialist (外专千人) in 2016. Over his career, he has published more than 270 scientific papers, which have received approximately 15,000 citations, and he holds an h-index of 63 (according to Google Scholar).

稀有同位素前沿科学中心

2025年4月10日