Theoretical Nuclear Structure Physics

理论核结构物理

• 批准号: 0070858
• 负责人: Bruce Barrett
• 金额: $ 32.3万
• 依托单位: University of Arizona
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-06-15 至 2004-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0070858&HistoricalAwards=false
• 关键词: Theoretical; Nuclear; Structure; Physics

0070858Barrett Our goal is to understand the structure of atomic nuclei from first principles---namely, in terms of the free nucleon-nucleon (strong) interaction and many-body quantum mechanics. Toward this end, we havedeveloped a new "ab initio" shell-model approach, in which we treat all. A nucleons as active particles in an extremely large basis (model) space. We now have computer codes, which allow us to perform such calculations for nuclei up to A=16, i.e., 16 active nucleons, and have obtained reasonable and encouraging results for the light nuclei studied so far. We are presently performing detailed calculations for A=6 and 7 to study the rate of convergence of the binding energies, spectra, radii, etc., as the size of the model space is increased. A new computer code is now being tested to do calculations for 12C up to 10 million configuration space states, so that we can perform similar calculations for A=12 as we are now doing for A=6 and 7. One of our major accomplishments, to date, is the development of a technique for computing exactly the effective two-body shell-model interaction, which we have employed to solve the A=3 and 4 nucleon systems. From these exact solutions for A=3 and 4, we can extract the effective three-body and four-body interactions. We plan to utilize these effective three- and four-body interactions to construct an expansion for the effective A-nucleon shell-model interaction, which will greatly improve the convergence rate for our calculations. In the near future we will also include a real three-body interaction in our shell-model investigations.

0070858巴雷特我们的目标是从第一性原理---即自由核子-核子（强）相互作用和多体量子力学的角度来理解原子核的结构。 为此，我们开发了一种新的“从头算”壳模型方法，在其中我们对待所有。 在极大的基（模型）空间中核子作为活动粒子. 我们现在有了计算机代码，它允许我们对A=16的原子核进行这样的计算，即，16个活跃核子，并取得了合理的和令人鼓舞的结果，为轻核研究到目前为止。 我们目前正在对A=6和7进行详细的计算，以研究结合能、光谱、半径等的收敛速度，因为模型空间的大小增加。 现在正在测试一种新的计算机代码，用于计算12 C高达1000万个配置空间状态，因此我们可以对A=12进行类似的计算，就像我们现在对A=6和7所做的那样。迄今为止，我们的主要成就之一是发展了一种精确计算有效的两体壳模型相互作用的技术，我们已经用它来求解A=3和4的核子系统。从A=3和4的精确解中，我们可以提取有效的三体和四体相互作用。 我们计划利用这些有效的三体和四体相互作用来构造有效的A核子壳模型相互作用的展开，这将大大提高我们计算的收敛速度。 在不久的将来，我们也将包括一个真实的三体相互作用在我们的壳模型研究。