Improved tests of Lorentz and CPT symmetry using noble gas and hydrogen masers

这项实验研究计划的目的是分别用惰性气体(129Xe/3He)塞曼脉泽和氢脉泽对中子和质子的洛伦兹和CPT对称性进行改进测试。在拟议的三年计划中，PI将优化升级后的129Xe/3He和氢脉泽的性能；对脉泽(即自旋进动)频率进行长期监测(超过一年)；表征可能的系统影响；并分析和展示这些测量的结果。这项研究的预期结果是，对量子引力的可能效应，如时空的各向异性或非对易性，以及对中子和质子与时变宇宙标量场的耦合具有前所未有的敏感性，而宇宙标量场是暗能量的领先候选者。该项目的更广泛影响涉及学生教育和应用，包括超极化稀有气体在低磁场下的磁共振成像，这些气体被吸入人体肺部，用于研究基本的肺部生理学和哮喘和肺气肿等疾病。

This experimental research program is aimed at performing improved tests of Lorentz and CPT symmetry of the neutron and the proton using a noble gas (129Xe/3He) Zeeman maser and a hydrogen maser, respectively. In the proposed three-year program the PI will optimize the performance of the upgraded 129Xe/3He and hydrogen masers; perform long-term monitoring (more than one year) of maser (i.e., spin precession) frequencies; characterize possible systematic effects; and analyze and present the results of these measurements. The expected result of this study is unprecedented sensitivity to possible effects of quantum gravity such as an anisotropy or non-commutativity of space-time, and to the coupling of neutrons and protons to a time-varying cosmological scalar field, which is a leading candidate for dark energy. The broader impact of the program involves student education as well as applications, including MRI at low magnetic fields of hyperpolarized noble gas inhaled into human lungs for studies of basic pulmonary physiology and diseases such as asthma and emphysema.