Speaker
Description
There is a growing consensus in recent multi-messenger astronomy that the neutron star merger (NSM) as well as core collapse supernova (CCSN) and collapsar (which is very massive single star collapsing to a black hole) could be a possible site for the r-process nucleosynthesis. We will first discuss when and how these three astrophysical sites have contributed to enrichment of the r-process elements in the universe in our Galactic chemical evolution model [1]. We will then discuss the roles of nuclear fission, neutron-captures, beta-decays, nuclear isomers, and the magnetic fields in each of these astrophysical sites of the r-process.
These explosive phenomena emit extremely large flux of energetic neutrinos and provide unique information to study the neutrino-nucleus interactions in high-density environments through the nuclosynthesis [2,3]. We will secondly discuss the neutrino-process and propose how to determine the still unknown neutrino mass hierarchy in terms of collective and MSW effects on the nuclear abundances of specific nuclei produced in CCSN and collapsar nucleosynthesis. We will also discuss the critical roles of not only the primary neutrino-nucleus reactions but also the radioactive nuclear reactions to secondarily destroy these neutrino-isotopes [4].
[1] Y. Yamazaki, Z. He, T. Kajino, G. J. Mathews, M. A. Famiano, X.-D. Tang, J.-R. Shi, ApJ. 933 (2022), 112.
[2] H. Sasaki, Y. Yamazaki, T. Kajino, M. Kusakabe, T. Hayakawa, M.-K. Cheoun, H. Ko, G. J. Mathews, ApJ. 924 (2022), 29.
[3] H. Ko, M.-K. Cheoun, E. Ha, et al., ApJ. 891 (2020), L24; H. Ko, D. Jang, M.-K. Cheoun, M. Kusakabe, H. Sasaki, X. Yao, T. Kajino, T. Hayakawa, M. Ono, T. Kawano, G. J. Mathews, ApJ. (2022), in press.
[4] X. Yao, M. Kusakabe, T. Kajino, S. Cherubini, S. Hayakawa, and H. Yamaguchi,
In European Physical Journal Web of Conferences, vol. 260 (2022), p. 01007.