讲座题目：Effects of beyond mean field approximation and tensor forces on Gamow-Teller and beta decay of magic nuclei
主讲人：Hiroyuki Sagawa 教授
主持人：周先荣 教授
开始时间：2024-05-20 10:00
讲座地址：闵行校区物理楼223会议室
主办单位：物理与电子科学学院
报告人简介：
Hiroyuki Sagawa教授是日本理化学研究所仁科中心和会津大学数理学中心教授与主任、国际知名的原子核物理学家。1975年毕业于日本东北大学后，先后在世界各地的顶尖研究机构如丹麦的Niels Bohr研究所、美国密歇根州大学、日本东京大学以及荷兰阿姆斯特丹核能与高能研究所等地进行研究工作。同时，还担任法国巴黎南大学、瑞典Lund institute of technology和意大利Milano University的客座教授。在原子核物理领域，Sagawa 教授在核结构、核转动、巨共振、张量相关的HF计算、弱束缚核中对关联效应和双核子关联、QCD求和规则、电荷对称性破缺等方面取得了突出成就。他在顶尖学术期刊如PRL、PPNP等发表了500多篇重要学术论文，并撰写了多本包括量子力学在内的教科书。他的研究成果在国际上产生了深远影响，为原子核物理领域做出了重要贡献。
报告内容：
The self-consistent Hartree-Fock (HF)+subtracted second random phase approximation (SSRPA) calculations based on the Skyrme energy density functions (EDFs) are pperformed for the Gamow- Teller (GT) excitations of four closed shell nuclei 48Ca, 90Zr, 132Sn, and 208Pb to study the systematic trend of SSRPA on the description of GT strength distributions with respect to the excitation energy and the width [1]. We apply also the SSRPA model including tensor force to the decay half-lives in magic and semi-magic nuclei, 34Si, 68,78Ni and 132Sn with Skyrme EDFs. The inclusion of the two particle-two hole (2p-2h) configurations in the SSRPA model shifts low-lying GT states downwards. It leads to an increase of the β decay phase space, which ensures the half-lives of the four nuclei are finite and reduces the β decay half-lives dramatically. The effect of tensor interaction on the β decay half-life in SSRPA model is also pointed out to change largely the half-lives by about one to two orders of magnitude with respect to the ones obtained without tensor force [2]. We further studt magnetic dipole (M1) transitions of magic nuclei to disentangle the role of triplet-even and triplet-odd tensor forces in the spin-isospin excitations [3]. References [1] M. J. Yang, C. L. Bai, H. Sagawa, and H. Q. Zhang, Phys. Rev. C 106, 014319 (2022). [2] M. J. Yang, H. Sagawa, C. L. Bai, and H. Q. Zhang, Phys. Rev. C 107, 014325 (2023). [3] M. J. Yang, H. Sagawa, C. L. Bai, and H. Q. Zhang, Phys. Rev. C in press (2024).
