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Spin correlation in pion-nucleus reaetions

介子核反应中的自旋相关性

基本信息

批准号：
08640376
负责人：
KUME Kenji
金额：
$ 1.47万
依托单位：
Nara Women's University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1998
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08640376/
关键词：
Pion Nuclear reaction Pion production reaction momentum space pionic atom auxiliary-field Monte Carlo パイ中間子スピン相関荷電交換反応芯偏極

项目摘要

I have obtained the following results.1. I have carried out the finite-range DWBA calculation of the pion energy spectrum for (p, pi^-) reactions near threshold for the first time. Good agreement with the experimental data is obtained. I have also made predictions of the (p, pi^-) spectrum in higher energy region.2. The parameters in the pion-nucleus optical potential in low-energy region is known to be difficult to determine uniquely due to the long wavelength of the pions. I have pointed out the possibility of fixing these parameters from the study of the quadrupole hyperfine component in deeply bound pionic atoms.3. The wave equations such as Schrodinger or Dirac equations are often treated in the momentum space. In this case, the long-range Coulomb force causes numerical difficulty. We proposed a simple and quite accurate numerical method to treat the Coulomb force in momentum space.4. We have analyzed the photo-disintegration cross sections in ^3He and ^4He according to the phenomenological quasi-deuteron model. Our model successfully decribe the overall features of the recent experimental results.5. We have developed a novel algorithm which enables us to treat the excited-state properties of the quantum many-body system based on the auxiliary-field Monte Carlo method. We have applied this method to some exactly solvably models and have examined the applicability of this method to realistic cases.

我得到了以下结果。1.本文首次用有限程DWBA方法计算了（p，π ^-）反应阈附近的π能谱。与实验数据吻合良好。对高能区的（p，π ^-）谱也作了预测.众所周知，由于π子的波长较长，低能区π子-核光学势中的参数很难唯一确定。通过对深束缚原子中四极超精细分量的研究，指出了确定这些参数的可能性。波动方程如薛定谔方程或狄拉克方程常在动量空间中处理。在这种情况下，长程库仑力导致数值困难。提出了一种简单而精确的数值方法来处理动量空间中的库仑力.我们根据唯象准氘核模型分析了^3He和^4He的光致衰变截面。我们的模型成功地描述了近期实验结果的总体特征.我们发展了一种新的算法，它使我们能够处理激发态的量子多体系统的基础上的量子场蒙特卡罗方法的性质。我们已经将这种方法应用到一些精确可解的模型中，并检验了这种方法对实际情况的适用性。