Precision measurements with polarized spins

这项研究计划旨在对超越粒子物理标准模型的新物理进行三次精确的实验探索。这些实验使用的是与Xe-129和He-3同时工作的脉塞。通过将其中一个稀有气体脉泽稳定到频率基准，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。将进行的实验包括：(I)对中子的基本洛伦兹不变性(相对论的基本方面之一)和CPT(电荷共轭、宇称和时间反转)对称性的灵敏测试；(Ii)对扭转引力效应的数量级改进搜索，如果时空具有Riemann-Cartan几何的话；以及(Iii)灵敏地搜索中子区的反常自旋-自旋相互作用。对于实验(一)和(二)，预计该项目将比以前的最佳限度有一个数量级的改进。如果观察到一种效应，我们对基础物理学的大部分理解将不得不从根本上改变。实验(III)将提供对这一效应的首次灵敏探索。该计划的广泛影响包括将本研究基于原子物理学的精密测量技术应用于开发新的生物医学成像工具(例如，在吸入到人体肺部的超极化稀有气体的低磁场下的磁共振成像(MRI))，以及开发使用钻石中的氮空位中心的高灵敏度磁强计。其他更广泛的影响包括广泛的学生培训，继续成功地侧重于纳入学生和博士后的精密测量技术，并对他们进行培训，这些学生和博士后是科学和工程领域代表性不足群体的成员。

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.