Electron Magnetic Moment, Fine Structure Constant, Mass Ratios, Laser Spectroscopy and QED

这个项目代表了一系列实验的延续，这些实验对基本量和对称性进行了越来越严格的测试，包括：1。电子磁矩（通常称为它的g值）精细结构常数alpha3。用轻子对CPT（电荷-宇称-时间）不变性的最严格检验。质子质量与电子质量之比这项研究的技术衍生品已被纳入离子回旋共振波谱学和磁共振成像，并且有前途的新探测器的改进仍在继续，显示出更广泛的适用性。一个更好的alpha值对于确定一个技术社会所需的一系列基本常数是至关重要的。量子电动力学（QED）将α纳入其对物质和光相互作用的描述中。它是量子场论的原型，是描述强相互作用和引力的理论努力试图模仿的模型。QED的一个突出成就是预测了电子磁矩g和α之间的关系，这使得α可以通过测量g来确定。由于成功地计算了描述这种关系的参数，QED理论现在对g的不确定性比以前的测量减少了43倍。因此，对g的充分改进的测量将更准确地确定alpha 43时间。对alpha的独立测量，以及对g的测量，将测试QED的精确度达到前所未有的水平，这是任何理论和实验中最精确的比较。实验精度，加上正在进行的计算中所期望的理论精度，应该能够区分从量子霍尔效应、交流约瑟夫森效应和中子测量中测量到的不一致的α值。为这项工作开发的碘钟和光学梳，这些技术在通信方面具有更广泛的适用性，将使绝对频率测量和更准确的频率间隔测量成为可能。

This project represents a continuation of a long series of experiments that pose ever-increasingly more stringent tests of fundamental quantities and symmetries, including:1. the electron magnetic moment (often called its g value)2. the fine structure constant alpha3. most stringent test of CPT (charge-parity-time) invariance with leptons4. the ratio of the masses of the proton and electron5. the proton and antiproton magnetic momentsTechnological spinoffs of this research have been incorporated into ion cyclotron resonance spectroscopy and magnetic resonance imaging, and the improvement of promising new detectors continues, demonstrating broader applicability. A better value of alpha is crucial to determining a number of the set of fundamental constants that are needed by a technological society. Quantum electrodynamics (QED) incorporates alpha into its description of the interaction of matter and light. It is the prototype quantum field theory, serving as the model which theoretical efforts to describe strong interactions and gravity seek to emulate. An outstanding achievement of QED is the predicted relationship between the electron magnetic moment g and alpha, which allows alpha to be determined by measuring g, Given the success of calculating the parameters describing this relationship, QED theory now contributes 43 times less uncertainty to g than do previous measurements. A sufficiently improved measurement of g will thus determine alpha 43 time more accurately. An independent measurement of alpha, along with the measurement of g, will test QED to an unprecedented level of accuracy the most precise comparison of any theory and experiment. The experimental precision, with the theoretical accuracy expected in calculations underway, should allow distinguishing between inconsistent values of alpha measured from the quantum Hall effect, the ac Josephson effect, and from a neutron measurement. An iodine clock and optical comb developed for this work, technologies of much broader applicability for communications, will make possible absolute frequency measurements and more accurate measurements of frequency intervals.