Gabrielse G, Hanneke D, Kinoshita T, Nio M, Odom B
Lyman Laboratory, Harvard University, Cambridge, Massachusetts 02138, USA.
Phys Rev Lett. 2006 Jul 21;97(3):030802. doi: 10.1103/PhysRevLett.97.030802. Epub 2006 Jul 17.
Quantum electrodynamics (QED) predicts a relationship between the dimensionless magnetic moment of the electron (g) and the fine structure constant (alpha). A new measurement of g using a one-electron quantum cyclotron, together with a QED calculation involving 891 eighth-order Feynman diagrams, determine alpha(-1)=137.035 999 710 (96) [0.70 ppb]. The uncertainties are 10 times smaller than those of nearest rival methods that include atom-recoil measurements. Comparisons of measured and calculated g test QED most stringently, and set a limit on internal electron structure.
量子电动力学（QED）预言了电子的无量纲磁矩（g）与精细结构常数（α）之间的一种关系。利用单电子量子回旋加速器对g进行的一项新测量，以及涉及891个八阶费曼图的QED计算，确定α⁻¹ = 137.035 999 710 (96) [0.70 ppb]。其不确定性比包括原子反冲测量在内的最相近竞争方法的不确定性小10倍。对测量值与计算值g的比较对QED进行了最严格的检验，并对电子内部结构设定了一个限制。
