Precision measurements with polarized spins

该研究计划旨在对粒子物理学标准模型之外的新物理学进行三次精确的实验研究。 实验中使用的微波激射器同时与氦-129和氦-3一起工作。 通过将其中一个惰性气体脉泽稳定在频率参考上，PI的团队可以控制脉泽的环境，然后将另一个脉泽用作新物理的传感器。 进行的实验包括：（i）基本洛伦兹不变性的灵敏度测试（相对论的基本方面之一）和CPT（电荷共轭，宇称，和时间反转）对称的中子;（ii）一个数量级的改进搜索扭转引力的影响，如果时空有一个黎曼-嘉当几何;和（iii）在中子扇区中灵敏地寻找异常自旋-自旋相互作用。 对于实验（i）和（ii），预计该项目将提供一个数量级的改进相比，以前的最佳限制。如果观测到一种效应，我们对基础物理学的许多理解将不得不发生根本性的改变。 实验（iii）将首次对这一效应进行灵敏的研究，其更广泛的影响包括将这项研究中基于原子物理学的精密测量技术应用于新型生物医学成像工具的开发（例如在吸入人肺的超极化惰性气体的低磁场下的磁共振成像（MRI）），以及利用金刚石中的氮空位中心开发高灵敏度磁力计。 其他更广泛的影响包括广泛的学生培训，继续成功地关注学生和博士后的精密测量技术的包容性和培训，这些学生和博士后是科学和工程领域代表性不足的群体的成员。

This research program is aimed at performing three precision experimental searches for new physics beyond the standard model of particle physics. The experiments use a maser operating simultaneously with Xe-129 and He-3. By stabilizing one of the noble-gas masers to a frequency reference, the PI's group can control the environment of the masers and then use the other maser as a sensor for new physics. The experiments to be carried out include: (i) a sensitive test of the fundamental Lorentz invariance (one of the fundamental aspects of the theory of relativity) and CPT (Charge conjugation, Parity, and Time reversal) symmetry for the neutron; (ii) an order-of-magnitude improved search for the effects of torsion gravity, which arises if spacetime has a Riemann-Cartan geometry; and (iii) a sensitive search for anomalous spin-spin interactions in the neutron sector. For experiment (i) and (ii) the project is expected to provide an order-of-magnitude improvement compared to the best previous limits. Much of our understanding of fundamental physics would have to be radically altered if an effect is observed. Experiment (iii) will provide a first sensitive search of this effect.Broader impacts of the program include the application of the atomic physics based precision measurement techniques of this research into the development of novel biomedical imaging tools (for example magnetic resonance imaging (MRI) at low magnetic fields of hyperpolarized noble gas inhaled into human lungs), as well as the development of a high-sensitivity magnetometer using nitrogen vacancy centers in diamond. Other broader impacts include extensive student training with continued successful focus on inclusion and training in precision measurements techniques of students and postdocs who are members of underrepresented groups in science and engineering.