Precision Measurement of Nuclear Magnetic and Electric Dipole Moments using Spin-Precession in Ultralow Fields

通过对超低磁场中极化稀有气体的核自旋进动的精确测量，我们打算解决基础物理中的两个悬而未决的问题：宇宙中物质对反物质的支配地位的起源和基本常数的时间稳定性的探索。像129Xe，d(Xe)这样的原子核的有限电偶极矩的存在将表明显著的CP破坏，这可能导致当今宇宙中的重子-反重子不对称。假设的核电偶极矩与外加电场的相互作用将使进动频率从纯Larmor频率偏移与d(Xe)成正比的量。通过使用3He-129Xe共磁测量，我们希望将目前公认的d(Xe)上限降低至少一个数量级，通过同时测量3He和129Xe的进动，我们打算以最高精度测量两个核磁矩的比率。通过这种方式，我们可以探索夸克质量的稳定性，并以量子色动力学标度参数为单位。这个项目与德国慕尼黑大学的Peter Fierlinger的nEDM提议密切相关，我们在DFG优先计划过程中与他合作。

By precision measurements of the nuclear spin precession of polarized noble gases in ultra-low magnetic fields, we intend to address two open problems in fundamental physics: the origin of the dominance of matter over antimatter in the universe and the probing of the temporal stability of fundamental constants.The existence of a finite electric dipole moment of a nucleus like 129Xe, d(Xe), would indicate a significant CP-violation that could have caused the baryon-antibaryon asymmetry in todays universe. The interaction of the postulated nuclear electric dipole moment with an additionally applied electric field would shift the precession frequency from the pure Larmor frequency by an amount that is proportional to d(Xe). By using 3He-129Xe comagnetometry, we expect to reduce the currently accepted upper limit for d(Xe) by at least one order of magnitude.By the simultaneous measurement of 3He and 129Xe precession, we intend to measure the ratio of the two nuclear magnetic moments with an utmost precision. In this way we can probe the stability of the quark mass and in units of the quantum chromdynamic scale parameter.This project is closely connected to the nEDM-proposal of Peter Fierlinger from TU Munich, with whom we have collaborated in the course of the DFG priority programme.