LLI and Solid State electron edm searches

这个实验研究计划的重点是继续实验，以测试局部洛伦兹不变性（LLI）和CPT（电荷共轭宇称时间）不变性。LLI是相对论的基本假设之一，它认为物理定律在所有局部惯性系中都是相同的。 虽然我们知道，如果改变粒子的电荷、系统的宇称或时间的方向，实验可能会给出不同的结果，但如果同时改变这三个方面，CPT不变性预测什么都不会改变。 到目前为止还没有证据表明情况并非如此。为了得到结果，该小组比较了汞和铯磁力计的相对进动频率，作为外加磁场相对于恒星方向的函数。 这个实验的早期版本建立了几个可能违反这些对称性的最佳限制。 在此期间，实验已经完全重建，该小组预计实验精度将提高100倍。 在这个水平上，实验应该提供违反LLI和CPT的几种可能机制的最严格测试。 该项目的更广泛影响涉及一个特别强大的本科生计划，该计划成功地培养了一些未来的科学家，并有望继续这样做。

This experimental research program focuses on the continuation of an experiment to test Local Lorentz Invariance (LLI) and CPT (charge conjugation parity time) invariance. LLI, one of the fundamental postulates of the theory of relativity, is the notion that the laws of physics are the same in all locally inertial frames. While it is known that an experiment may give a different result if one changes the charge on a particle or the parity of the system or the direction of time, if changes are made in all three at the same time, then CPT invariance predicts that nothing may change. To date there is no evidence to indicate that this is not the case.To get at the results the group compares the relative precession frequencies of mercury and cesium magnetometers as a function of the orientation of an applied magnetic field with respect to the fixed stars. An earlier version of this experiment established the best limits on several possible violations of these symmetries. In the interim the experiment has been completely rebuilt, and the group expects to achieve a factor of 100 improvement in the experimental precision. At this level the experiment should provide the most stringent test of several possible mechanisms for violating LLI and CPT. The broader impact of the project involves a particularly strong undergraduate program that has successfully trained a number of future scientists and may be expected to continue to do so.