LLI and Solid State electron edm searches

这项实验研究计划集中在测试局域洛伦兹不变性(LLI)和电荷共轭奇偶时间(CPT)不变性的实验的继续。相对论的基本假设之一是，物理定律在所有局部惯性系中都是相同的。虽然众所周知，如果一个人改变粒子上的电荷、系统的宇称或时间方向，实验可能会得到不同的结果，但如果同时改变这三个方面，那么CPT不变性预测什么都不会改变。到目前为止，没有证据表明情况并非如此。为了得出这一结果，该小组比较了汞和铯磁力计的相对进动频率随外加磁场相对于固定恒星的方向的函数。这项实验的早期版本对这些对称性的几种可能的违反设定了最佳限制。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。在这个层面上，实验应该提供违反LLI和CPT的几种可能机制中最严格的测试。该项目的更广泛影响涉及一个特别强大的本科项目，该项目已经成功地培养了一批未来的科学家，而且可能会继续这样做。

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.