Search for the Electron EDM using Cs and Rb in Optical Lattice Traps

将进行一项实验，以寻找电子的电偶极矩(EDM)，使用冷的Cs和Rb原子。将根据过去三年学到的知识对仪器进行适当改装，然后开始收集电火花加工数据。该实验使用原子发射并加载到一对平行的一维远离共振的光学晶格陷阱中，这些陷阱位于空间的磁屏蔽区，由激光冷却和光泵浦。EDM将通过观察在两个陷阱中相反方向的电场中的相干原子演化来测量。据预测，该实验将对小至3x10-30e-cm的电火花加工敏感，这是目前限制的300倍。具有永久EDM的粒子意味着时间反转不变性和宇称不变性都被违反。事实上，这两个对称性在标准物理模型中都被违反了，该模型预测基本粒子的EDM非常小，但不为零。对标准模型的拟议扩展倾向于预测更大的EDM，接近目前实验的上限。如果继续没有观测到EDM，将排除对标准模型进行许多可能的扩展。相反，如果观测到EDM，这将是第一个不能被纳入标准物理模型的任何类型的实验结果。如果在原子或分子中发现了电火花加工，在本实验中使用的碱性原子中提取基础物理将比在其他更复杂的原子或分子中提取的可靠得多。这个实验解决了一个对基本粒子物理学至关重要的问题。这样的问题通常是通过高能实验来解决的，但在这种情况下，原子物理的精密工具可以应用于低得多的能量系统，伴随着更低的成本。本科生和研究生将接受实验研究方法的培训，并培养技能，为国家的科学工作做准备。

An experiment will be pursued to search for the electric dipole moment (EDM) of the electron using cold cesium and rubidium atoms. The apparatus will be appropriately modified based on what has been learned over the last three years, and then EDM data collection will commence. The experiment uses atoms launched and loaded into a pair of parallel one-dimensional far-off-resonant optical lattice traps in a magnetically shielded region of space, laser-cooled and optically pumped. EDMs will be measured by observing coherent atom evolution in electric fields that are directed oppositely in the two traps. It is projected that the experiment will be sensitive to an EDM as small as 3x10-30 e-cm, which is a 300-fold improvement over the current limit. A particle with a permanent EDM implies that both time-reversal invariance and parity invariance are violated. Both of these symmetries are in fact violated in the standard model of physics, which predicts very small, but non-zero EDMs for fundamental particles. Proposed extensions to the standard model tend to predict much larger EDMs, close to the current experimental upper limit. Continued non-observation of EDMs would rule out many possible extensions to the standard model. Conversely, should an EDM be observed, it would be the first experimental result of any kind that cannot be incorporated into the standard model of physics. If an EDM is found in an atom or molecule, the extraction of the fundamental physics will be far more reliable in the alkali atoms used in this experiment than in other more complicated atoms or molecules. This experiment addresses a question of fundamental importance to elementary particle physics. Such questions are normally addressed with high energy experiments, but in this case the precision tools of atomic physics can be applied to a much lower energy system, with a concomitant lower cost. Undergraduates and graduate students will be trained in the experimental research methods and develop skills preparing them for the nation's scientific work force.