Ultrahigh-Sensitivity Search for an Electric Dipole Moment of^<129>Xe atom by Means of Nuclear Spin Maser with Artificial Feedback

利用人工反馈核自旋微波激射器超高灵敏度搜索^<129>Xe原子的电偶极矩

基本信息

批准号：
15104003
负责人：
ASAHI Koichiro
金额：
$ 63.23万
依托单位：
Tokyo Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (S)
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

Violation of CP invariance, known for more than 40 years in neutral K decay and recently confirmed also in B decay, remains one of vital subjects in contemporary particle physics. The standard Model (SM) includes the CP violation in a form of complex phase in the K-M matrix elements and well represents the observed flavor-changing K and B decays, but never provide a permanent electric dipole moment (EDM) of detectable size. On the other hand, models proposed beyond the SM, such as supersymmetric one, predict sizeable values for EDM, thus rendering EDM an exclusive position as a probe of physics beyond the SM. The present research has aimed at development of new scheme of nuclear spin maser that enables precision determination of spin precession frequency, in order to pave a route for ultrahigh-sensitivity search for an EDM in a ^<129>Xe atom.^<129>Xe nuclear spins of Xe gas contained in a 22 mm-diameter glass cell were successfully polarized by spin exchange with optically pumped Rb vapor, their precession was detected by probe Laser light, and a self-sustaining precession by means of an artificial feedback was observed for the first time. The observed precision in frequency proved to improve as Δv ∝ 1/T^<1.5> as a function of the measurement time T until T = 3000 s, and then tended to be flattened. Following this result, we worked out several improvements in the setup, including the magnetic shielding, magnet current stabilization, Laser operation and wavelength stabilization, and cell temperature control, and finally attained Δv = 9.3 nHz (amounting to EDM sensitivity of Δd 〜 9×10^<-28> ecm) in a measurement time T = 30000 s. Also, a number of issues were identified that have decisive effects on the v precision and definitely deserve further work for improvement. We thus conclude that the present work has confirmed effectiveness of novel method for the atomic EDM search, and has clarified the directions that should enable the long awaited EDM precision.

在中性K衰减中闻名已有40多年的CP不变性，最近在B衰减中也证实了CP不变性，仍然是当代粒子物理学中的重要主题之一。标准模型（SM）在K-M矩阵元素中以复杂相的形式包括CP违规，并且井代表观察到的改变风味的K和B衰变，但切勿提供可检测尺寸的永久性电偶极矩（EDM）。另一方面，提出的模型超出了SM（例如超对称性），预测EDM的可观值，从而使EDM成为独家位置，作为SM之外的物理学探测器。本研究旨在开发新的核自旋梅瑟方案，以精确确定旋转频率，以铺平一种超高敏感性的途径。首次观察到光，通过人工反馈进行自我维持的预防。观察到的频率精度被证明是ΔV∝1/t^<1.5>作为测量时间t的函数，直到t = 3000 s，然后倾向于扁平。在此结果之后，我们在设置方面进行了一些改进，包括磁性屏蔽，磁铁电流稳定，激光稳定和波长稳定以及细胞温度控制，最后连接ΔV= 9.3 nhz（在测量时间t = 30,000 s = 30,000 s中的EDM敏感性（构成ΔD〜9×10^<-28> ECM的EDM敏感性）。此外，确定了许多问题，这些问题已决定对V精度的影响，并且绝对值得进一步的改进。因此，我们包括当前的工作已经确认了原子EDM搜索的新方法的有效性，并阐明了应该使期待已久的EDM精度的方向。