Nucleosynthesis of Radioactive Nuclei in Explosive Stellar Objects and Cosmic and Galactic Ages

我们尝试在高精度的n元素上建立模型，总结了本项目在爆炸核合成、观测天文和核实验方面的理论研究进展，将我们的理论模型计算结果与观测到的缺金属晕星中长寿命放射性原子核元素丰度进行了比较，发现U-Th天文钟比UT-Eu天文钟精度更高。中小质量AGB恒星在超新星爆炸的快中子俘获过程（r-过程）和战争阶段的慢中子俘获过程（s-过程）中产生长寿命的放射性核。对天体物理核合成环境的物理条件进行了理论模拟，发现在轻质量富中子不稳定核上的中子和α诱导反应和中重质量富中子不稳定核上的中子俘获反应在r过程中起着重要的作用。这些截面数据来自核实验，这些实验是在世界上的核物理和粒子物理实验设施中进行的，包括RIKEN和CNS，东京大学。利用粒子和原子核的量子理论，对超新星引力坍缩过程中不可测的核数据和中微子-核相互作用的截面进行了理论计算。利用这些粒子和核物理学的实验和理论输入，我们可以以更高的精度进行核合成计算，并提供可靠的r过程元素的初始丰度分布。然后，我们将这些产品应用于银河系化学演化，以理论上预测长寿命放射性重元素（如Th和u）元素丰度的时间变化，并将理论预测与配备SUBARU望远镜的高色散光谱仪的观测数据相结合，我们试图在我们构建的r过程元素宇宙色计中估计早期金属缺乏的晕星的年龄。我们将结果与观测宇宙学对宇宙年龄的约束（包括几个宇宙学参数）以及两种年龄之间的碟形一致性进行了比较，并研究了大挂核合成、宇宙微波背景各向异性和Ia型超新星的光度-红移关系，以构建与Less项目确定的宇宙和星系相一致的宇宙学模型

We tried model construction on of n tern with high precision, summing the progress in theoretical studies of explosive nucleosynthesis, observational anal astronomy, and nuclear experiment in this project Comparing our theoretical model calculations with observed elemental abundances of long-lived radioactive nuclei in metal-deficient halo stars, we found that the U-Th chronometer has better precision than the UT-Eu chronometer. Long-lived radioactive nuclei are produced d either in rapid-neutron capture process (r-process) in supernova explosion and in slow-neutron capture process (s-process) in War stage of small-to-intermediate mass AGB stars. Physical conditions of astrophysical nucleosynthesis environments were dared theoretically in numerical simulation of explosive nude synthesis It was found that neutron and alpha induced reactions on light mass neutron-rich unstable nuclei and neutron capture reactions on intermediate-to-heavy mass neutron-rich unstable nuckei play the importa … More nt roles in the r-process. These cross section data were taken from nuclear experiments which were carried outin experimental facilities of nuclear and particle physics in the world including RIKEN and CNS, University of Tokyo. Unmeasured nuclear data and cuss sections for neutrino-nucleus interactions, which are very important for gravitational collapse of supernovae, were theoretically calculated by the use of the quantum theory for particles and nuclei. Using these experimental and theoretical inputs hum particle and nuclear physics we can carry out nucleosynthesis calculations with better precision and provide reliable initial abundance distribution of the r-process elements. We then applied these products to Galactic chemical evolution in order to theoretically predict time variation of elemental abundances at long-lived radioactive heavy elements such as Th and U. Combining the theoretical prediction with observed data which were taken by using High Dispersion Spectrograph equipped with SUBARU Telescope, we tried to estimate the age of the early generation, metal-deficient halo stars in our constructed cosmochrometers of the r-process elements. We compared the results with the constraints on the cosmic age which was determined from observational cosmology which include several cosmological parameters, and dish consistency between both ages We also studied big-hang nucleosynthesis, cosmic microwave background anisotropy, and luminosity-redshift relation of type Ia supernovae in order to construct cosmological model that is consistent with the cosmic and Galacticages determined in our project Less