Application of Dyson-type boson mapping method to intermediately-excited collective states

戴森型玻色子映射方法在中间激发集体态中的应用

• 批准号: 07640415
• 负责人: TAKADA Kenjiro
• 金额: $ 0.83万
• 依托单位: KYUSHU uNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07640415/
• 关键词: medium-heavy nuclei; octupole phonon; hashing method; boson mapping; ボゾン写像

(1) We have completed a set of computer programs to analyze multi-octupole-phonon coolective states in medium-heavy nuclei. (The source programs consist of about 40,000 lines.)(2) These programs have been applied for the multi-octupole-phonon excited states in ^<146,148>Gd. The precise numerical results show that the coupling effect between neutron pair and octupole particlehole modes plays and essential role for the enhancement of octupole collectivity. The result has been published in our paper, "K.Takada and Y.R.Shimizu : Two-Octupole-Phonon States in ^<146,148>Gd, Prog.Theor.Phys.95, No.6 (1996) 1121-1143".(3) In developing the programs mentioned above, we have invented a "simplified hashing method" published in a paper "K.Takada : To apply hashing method to numerical calculations, Report of Computer Center, Kyushu University, 28 (1995) 129". We found that our new hashing method is quite useful for a big size of numerical calculation which needs a huge amount of core memories. Using this method, we have made it possible to carry out a big size of computation, which appeared impossible even on a main frame before, on a small personal computer.(4) Since the above programs are in the particle-hole representation, the particle-number conservation is strictly fulfillled. However they are applicable only for a restricted area adjacent to closed shell. To overcome the defect, we have developed a new algolithm of program for the Dyson boson mapping in the quasi-particle representation, the main part of which has been completed. The application of this new program for a wide range of realistic nuclei is a problem of near future.

(1)我们已经完成了一套分析中重核多八极声子冷态的计算机程序。(The源程序由大约40，000行组成。(2)这些程序已应用于^<146，148>Gd的多八极声子激发态。精确的数值计算结果表明，中子对与八极粒子-空穴模的耦合效应对八极集体的增强起着至关重要的作用。这一结果已发表在我们的论文“K.Takada和Y. R. Shimizu：Two-Octupole-Phonon States in ^<146，148>Gd，Prog.Theor.Phys.95，No.6（1996）1121-1143”中。(3)在开发上述程序的过程中，我们发明了一种“简化散列法”，发表在论文“K.Takada：To apply hashing method to numerical calculations，Report of Computer Center，Kyushu University，28（1995）129”中。我们发现，我们的新的散列方法是非常有用的大规模的数值计算，需要大量的核心内存。使用这种方法，我们已经有可能进行大规模的计算，这似乎是不可能的，即使在主机上，在一个小的个人计算机上。(4)由于上述程序是在粒子-空穴表象中进行的，因此严格满足粒子数守恒。然而，它们仅适用于封闭壳体附近的受限区域。为了克服这一缺陷，我们在准粒子表象中发展了一种新的Dyson玻色子映射算法，并完成了主要部分的程序设计。将这一新程序应用于大范围的实际原子核是一个不久的将来的问题。

项目成果

K.Takada: "To apply hashing method to numerical calculations" Report of Computer Center, Kyushu University. Vol.28, No.2. 129-135 (1995)

K.Takada：“将哈希方法应用于数值计算”九州大学计算机中心的报告。

Kenjiro Takada: "Two-Octupole-Phonon States in ^<146,148>Gd" Progress Theoretical Physics. 95・6. 1121-1143 (1996)

高田健二郎：“^<146,148>Gd 中的两个八极声子态”理论物理学进展 95・6（1996）。