Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA.
Phys Rev Lett. 2013 Mar 29;110(13):130801. doi: 10.1103/PhysRevLett.110.130801. Epub 2013 Mar 25.
For the first time a single trapped antiproton (p) is used to measure the p magnetic moment μ(p). The moment μ(p)=μ(p)S/(ℏ/2) is given in terms of its spin S and the nuclear magneton (μ(N)) by μ(p)/μ(N)=-2.792 845±0.000 012. The 4.4 parts per million (ppm) uncertainty is 680 times smaller than previously realized. Comparing to the proton moment measured using the same method and trap electrodes gives μ(p)/μ(p)=-1.000 000±0.000 005 to 5 ppm, for a proton moment μ(p)=μ(p)S/(ℏ/2), consistent with the prediction of the CPT theorem.
首次使用单个被捕获的反质子 (p) 来测量 p 磁矩 μ(p)。磁矩 μ(p)=μ(p)S/(ℏ/2) 由其自旋 S 和核磁子 (μ(N)) 给出，μ(p)/μ(N)=-2.792845±0.000012。4.4 百万分率 (ppm) 的不确定度比以前的测量小 680 倍。使用相同的方法和捕获电极测量质子磁矩，得到 μ(p)/μ(p)=-1.000000±0.0000005 到 5 ppm，对于质子磁矩 μ(p)=μ(p)S/(ℏ/2)，与 CPT 定理的预测一致。
