Nuclear structure at extreme

极端核结构

基本信息

批准号：
10044339
负责人：
YAZAKI Koichi
金额：
--
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for International Scientific Research.
财政年份：
1998
资助国家：
日本
起止时间：
1998 至无数据
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10044339/
关键词：
Isospin beta stability line stable nucleus unstable nucleus closed shell 32Mg magic number Monte Carlo shell model 高スピン状態高アイソスピン状態量子モンテカルロ対角化法トレント ect 極限状態原子核構造殻模型

项目摘要

In this research project, the nuclear structure has been studied at variousextremes. We first investigated the structure of nuclei at high isospin. High isospin indicates situations that the neutron number is greater than theproton number or vice versa. The z-component of isospin is given by (Z-N)/2 where Z and N mean the proton and neutron numbers, respectively. The magnitude of isospin, T, should be larger than or equal to Tz. In nuclei with equal numbers of neutrons and protons, Tz=0, and the ground and low-lying states are of T0. Low-isospin corresponds to the nuclei on and near the beta stability line (stable nuclei) where the proton and neutron numbers are equal or close to each other. On the other side, nuclei with large T are far from the beta stability line, being called unstable nuclei. It has been clarified during the past ten years that unstable nuclei have structure very different from the structure of stable nuclei. In this project, we studied 32Mg, which is an example of unstable nuclei, and its vicinity. The N20 is a magic number as well known. Therefore, on the standpoint of stable nuclei, 32Mg should be a neutron-closed nucleus, and should have a spherical ground state. This has been shown to be incorrect, experimentally and theoretically. On the contrary, studies on nuclei around 32Mg have hardly been done. We can now, however, carry out such studies by using the Monte Carlo shell model being developed by the group of the University of Tokyo. By such studies, it has been clarified that the change from stable nuclei does not occur suddenly at a certain nucleus but does occur gradually, and that the monopole component of the effective interaction plays a crucial role in this. In addition to the above studies, the spherical-deformed transition has been studied including high spin states.

在该研究项目中，已经在各种发挥作用中研究了核结构。我们首先研究了高isospin的核结构。高isospin表明中子数大于Proton数字，反之亦然。 Isospin的Z分量由（z-n）/2给出，其中z和n分别表示质子和中子数。同胞t的大小应大于或等于Tz。在具有相等数量的中子和质子的核中，TZ = 0，地面和低洼状态为T0。低issospin对应于β稳定线（稳定核）上和附近的核，其中质子和中子数相等或彼此接近。另一方面，具有较大T的核远离β稳定性线，称为不稳定的核。在过去的十年中，已经澄清了不稳定的核与稳定核的结构截然不同。在这个项目中，我们研究了32mg，这是不稳定核及其附近的一个例子。 N20是一个众所周知的魔术数字。因此，从稳定核的角度来看，32mg应为中子链核，并应具有球形基态。在实验和理论上，这已被证明是不正确的。相反，几乎没有对32mg的核研究进行研究。但是，我们现在可以通过使用东京大学开发的蒙特卡洛·壳壳模型进行此类研究。通过这样的研究，已经澄清说，稳定核的变化不会突然发生在某个核心，而是逐渐发生，并且有效相互作用的单极成分在此中起着至关重要的作用。除上述研究外，还研究了球形构造的过渡，包括高自旋状态。