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Spectroscopy of Antihydrogen

反氢光谱

基本信息

批准号：
15002005
负责人：
HAYANO Ryugo
金额：
$ 306.18万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Specially Promoted Research
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2007
项目状态：
已结题

项目摘要

The goal of this project was to test the CPT invariance (e. g., equality of particle vs antiparticle mass & charge) by means of precision spectroscopy of antihydrogen atoms and antiprotonic helium atoms.We studied in detail the formation mechanism of antihydrogen atoms, and found : 1) the dominance of 3-body recombination process, 2) produced antihydrogen atoms are likely to be in highly excited states, 3) antihydrogen atoms have much higher kinetic energy than was expected from the ambient temperature of some 10 K. In other words, although we can now produce antihydrogen atoms at a rate of a few hundred Hz, none of them is suitable for high-precision spectroscopy. In order to overcome this difficulty, we (ALPHAcollaboration) constructed a new setup comprising a superconducting Penning trap, a superconducting octupole coils and a pair of mirror coils, with which we are now attempting to magnetically trap antihydrogen atoms. As of today, none has been found yet.High-precision laser spectroscopy of antiprotonic helium atoms has been quite successful. We achieved a new CPT limit of proton/antiproton mass and charge comparison of 2x10-9, by the following methods : 1) we eliminated collisional effects by stopping ultra-low-energy antiprotons (decelerated by a linear antiproton decelerator) in an ultra-low-density helium gas target, 2) we developed a new laser system based on pulsed amplification of single-mode cw lasers, 3) the optical frequency comb technology was used to calibrate the laser frequencies. Our measurement resulted in the determination of proton-to-electron mass ratio to be 1836.152 674 ?} 0.000 005. This is almost as precise as the known proton-to-electron mass ratio of 1836.152 672 47 ?} 0.000 000 80 (codata 2006). Methods to further improve the precision have been identified, so that our measurements are likely to become more precise than the proton-mass measurement in a few years.

这个项目的目的是通过反氢原子和反质子氦原子的精密光谱来测试反氢原子的CPT不变性(例如，粒子与反粒子质量和电荷的相等)。我们详细地研究了反氢原子的形成机制，发现：1)三体复合过程的主导作用，2)产生的反氢原子很可能处于高激发态，3)反氢原子的动能比在大约10K的环境温度下预期的要高得多。换句话说，尽管我们现在可以以几百赫兹的速度产生反氢原子，但没有一个原子适合高精度的光谱。为了克服这一困难，我们(ALPHACollaboration)构建了一个新的装置，包括一个超导Penning陷阱，一个超导八极线圈和一对镜像线圈，我们现在正试图用它们来磁捕获反氢原子。到目前为止，还没有发现任何结果。反质子氦原子的高精度激光光谱分析已经相当成功。我们通过以下方法获得了质子/反质子质量和电荷比较的新的CPT极限为2×10~(-9)：1)我们通过阻止超低密度氦气靶中的超低能反质子(由线性反质子减速器减速)来消除碰撞效应；2)我们发展了一种基于单模连续激光脉冲放大的新的激光系统；3)利用光学频率梳技术校准了激光频率。我们的测量结果是质子与电子的质量比为1836.152 674？0.000 005。这几乎与已知的质子与电子质量比1836.152 672 47？0.000 000 80一样精确(Codata 2006)。进一步提高精度的方法已经确定，因此我们的测量很可能在几年内变得比质子质量测量更精确。

项目成果

期刊论文数量（99）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Laser spectroscopy of antiprotonic helium atoms and ions

反质子氦原子和离子的激光光谱

DOI：
发表时间：
2005
期刊：
CANADIAN JOURNAL OF PHYSICS 83
影响因子：
0
作者：
J. V. Jorgensen;et al.;G.Bonomi et al.;M. Toyoda;R.S.Hayano
通讯作者：
R.S.Hayano

Populations, lifetimes in the v=n・l・1=2, 3 metastable cascades of pHe+ measured by pulsed, continuous antiproton beams

通过脉冲、连续反质子束测量 v=n・l・1=2、3 个 pHe+ 亚稳态级联中的种群、寿命

DOI：
发表时间：
2004
期刊：
Physical Review A 70
影响因子：
0
作者：
M. Hori;et al.
通讯作者：
et al.

Past, Present and Future of Trapped Antiprotons

俘获反质子的过去、现在和未来

DOI：
发表时间：
2007
期刊：
影响因子：
0
作者：
M. Hori;et al.;N. Ono;N. Ono;R. S. Hayano
通讯作者：
R. S. Hayano

Spectroscopy of Long-Lived Antiprotonic He and Antihydrogen Formation

长寿命反质子 He 和反氢形成的光谱

DOI：
发表时间：
2006
期刊：
影响因子：
0
作者：
R. S. Hayano;R. S. Hayano;M. Toyoda;R. S. Hayano;R. S. Hayano
通讯作者：
R. S. Hayano

Prospect of CPT tests using antiprotonic helium and antihydrogen

使用反质子氦和反氢进行 CPT 测试的前景

DOI：
发表时间：
2005
期刊：
影响因子：
0
作者：
R. S. Hayano;R. S. Hayano;M. Toyoda;R. S. Hayano;R. S. Hayano;R. S. Hayano;M. Yamamoto;R. S. Hayano;R. S. Hayano;R. S. Hayano;M. Hori;R. S. Hayano;R. S. Hayano;R. S. Hayano
通讯作者：
R. S. Hayano