Basic Science Research by High Intensity Meson Beams

高强度介子束的基础科学研究

基本信息

批准号：
04044038
负责人：
YAMAZAKI Toshimitsu
金额：
$ 12.8万
依托单位：
Institute for Nuclear Study, 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：
1992
资助国家：
日本
起止时间：
1992 至 1993
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-04044038/
关键词：
Antiproton Metastable antiprotonic atom Laser resonance Deeply bound pionic atom High Tc superconducting oxide 3d-transition metal oxide Negative muonic oxygen Antiferromagnetism ミュオン μSR 高温超伝導磁性ミュオン原子物理反陽子原子中間子原子

项目摘要

Experiments on laser resonance spectroscopy on metastable antiprotonic atoms were carried out at CERN. When a pulsed laser with an energy matched to a transition from a metastable state to a short lived state is fired after the arrival of an antiproton, a sharp spike is expected to appear on a delayed part of the antiproton annihilation time spectrum. We used the antiproton beam of 200MeV/c from the Low Energy Antiproton Ring (LEAR) of CERN.We discovered a sharp spike at a laser wave length of 597.26nm which was assigned to a resonance transition from the (n, iota) =(39, 35) to the (38, 34) state. Thus, we have established that the metastability of antiprotons in helium arises from the metastable states of the neutral antiprotonic helium atomcule.Regarding the search for deeply-bound pionic atoms we prepared an experiment to be done at GSI in collaboration with a group in Germany.Various experiments were carried out at the TRIUMF muon facilities. One of the purposes of this project is … More to obtain the basic understanding of high Tc superconductors, especially the role of the copper-oxide layer structure and the contribution of oxygen to the superconductivity. Since the intense negative muon channel at TRIUMF was built by the collaboration between UTMSL and TRIUMF, the negative muon spin rotation method (mu^-SR) has been intensively applied to this subject.By using a single crystal of good quality, precise paramagnetic shift was obtained on the LaSrCuO system with its dependence on temperature, on dopant concentration and on magnetic field direction with respect to the crystal axis. The relaxation of negative muonic oxygen (mu^-O) has also been studied to get the dynamic aspect of the electron spin.One remarkable achievement is the success of the separation of mu^-O signals for different oxygen sites, which gives the hints for the role of oxygen.Also for water knowledge of chemical state of mu^-O can be obtained. For the basic understanding of mu^-O in metal oxides, the study of mu^-O in 3d transition metal oxides is inevitable. The study is performed on various 3d-transition metal oxides, especially the precise measurement of temperature dependence of paramagnetic shift in MnO reveals an interesting local magnetic ordering.Some of these achievements were reported at the muSR international conference in Maui. Less

欧洲核子研究组织（CERN）对亚稳态反质子原子进行了激光共振光谱实验，当反质子到达后发射能量与从亚稳态到短寿命状态的转变相匹配的脉冲激光时，预计会出现尖锐的尖峰。出现在反质子湮没时间谱的延迟部分我们使用了来自CERN低能反质子环（LEAR）的200MeV/c的反质子束。我们发现了。激光波长为 597.26nm 处的尖峰被指定为从 (n, iota) =(39, 35) 到 (38, 34) 态的共振跃迁，因此，我们确定了反质子的亚稳定性。氦中的中性源自中性反质子氦原子的亚稳态。关于寻找深层束缚的介子原子，我们准备了一个在 GSI 进行的实验与德国的一个小组合作。在 TRIUMF μ 子设施中进行了各种实验，该项目的目的之一是获得对高温超导体的基本了解，特别是氧化铜层结构和的作用。由于TRIUMF的强负μ子通道是由UTMSL和TRIUMF合作建立的，因此负μ子自旋旋转方法（mu^-SR）已被广泛应用于此。通过使用高质量的单晶，在 LaSrCuO 系统上获得了精确的顺磁位移，其依赖于温度、掺杂剂浓度和相对于晶轴的磁场方向负 μ 子氧的弛豫 (mu^)。还研究了电子自旋的动态方面。一项显着的成就是成功分离了不同氧位点的 mu^-O 信号，这为氧的作用提供了线索。对于水也是如此化学状态的知识为了对金属氧化物中的mu^-O有基本的了解，对3d过渡金属氧化物中mu^-O的研究是不可避免的。 MnO 中顺磁位移的温度依赖性的精确测量揭示了有趣的局部磁序。其中一些成果已在毛伊岛举行的 muSR 国际会议上报告。