Spin Responses in Nuclei and Nuclear Weak Processes in Stars

[摘要] New shell-model Hamiltonians which can successfuly describe spin-dependent transition rates in nuclei are applied to study nuclear weak processes in stars. New v-induced reaction cross sections in12C and56Fe evaluated by the new Hamiltonians are shown to reproduce well the experimental data. Nucleosynthesis of light elements in supernova explosions (SNe) as well as v oscillation effects are discussed with the new cross sections. Electron capture and β-decay rates in stellar environments are re-evaluated in fp- and sd-shell nuclei. Nucleosynthesis in Type-Ia SNe, rp-process and X-ray burst are discussed with the new reaction rates in Ni isotopes. Important roles of accurate e-capture and β-decay rates in sd-shell nuclei on the cooling of stars with 8-10 solar masses by nuclear URCA processes and the fate of the stars are demonstrated. β-decay half-lives of waiting-point nuclei at N =126 are evaluated by shell- model calculations, and r-process nucleosynthesis up to Th and U region in both core-collapse SNe and binary neutron star mergers are studied.

[发布机构] Department of Physics, College of Humanities and Sciences, Nihon University, Sakurajosui 3-25-40, Setagaya-ku, Tokyo; 156-8550, Japan^1

[效力级别] 天文学 [学科分类] 天文学(综合)

[关键词] Binary neutron stars;Electron capture;Light elements;Oscillation effects;R-process nucleosynthesis;Reaction cross-sections;Supernova explosion;Transition rates