International Research Center for Big-Bang Cosmology and Element Genesis, and School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191, People's Republic of China. Division of Theoretical Astronomy, National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo, 181-8588, Japan. Department of Astronomy, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-033, Japan.
Rep Prog Phys. 2017 Aug;80(8):084901. doi: 10.1088/1361-6633/aa6a25. Epub 2017 Mar 30.
Current models for the r process are summarized with an emphasis on the key constraints from both nuclear physics measurements and astronomical observations. In particular, we analyze the importance of nuclear physics input such as beta-decay rates; nuclear masses; neutron-capture cross sections; beta-delayed neutron emission; probability of spontaneous fission, beta- and neutron-induced fission, fission fragment mass distributions; neutrino-induced reaction cross sections, etc. We highlight the effects on models for r-process nucleosynthesis of newly measured β-decay half-lives, masses, and spectroscopy of neutron-rich nuclei near the r-process path. We overview r-process nucleosynthesis in the neutrino driven wind above the proto-neutron star in core collapse supernovae along with the possibility of magneto-hydrodynamic jets from rotating supernova explosion models. We also consider the possibility of neutron star mergers as an r-process environment. A key outcome of newly measured nuclear properties far from stability is the degree of shell quenching for neutron rich isotopes near the closed neutron shells. This leads to important constraints on the sites for r-process nucleosynthesis in which freezeout occurs on a rapid timescale.
目前的 r 过程模型被总结，重点强调了核物理测量和天文观测的关键约束。特别是，我们分析了核物理输入的重要性，如β-衰变率；核质量；中子俘获截面；β延迟中子发射；自发裂变、β和中子诱导裂变的概率，裂变碎片质量分布；中微子诱导反应截面等。我们强调了新测量的β-衰变半衰期、近 r 过程路径的富含中子核的质量和光谱对 r 过程核合成模型的影响。我们概述了核心坍缩超新星中原始中子星上方的中微子驱动风以及来自旋转超新星爆炸模型的磁流体动力学喷流的 r 过程可能性。我们还考虑了中子星合并作为 r 过程环境的可能性。远离稳定性的新测量核性质的一个关键结果是闭壳层附近富含中子的同位素的壳层猝灭程度。这对 r 过程核合成的地点产生了重要的限制，在这些地点中，快速冻结发生在快速的时间尺度上。
