One-Particle Measurement of the Antiproton Magnetic Moment

Abstract

\DeclareRobustCommand{\pbar}{\HepAntiParticle{p}{}{}\xspace} \DeclareRobustCommand{\p}{\HepParticle{p}{}{}\xspace} \DeclareRobustCommand{\mup}{$\hat{I}{¼}_p${}{}\xspace} \DeclareRobustCommand{\mupbar}{$μ_{\pbar}${}{}\xspace} \DeclareRobustCommand{\muN}{$\hat{I}{¼}_N${}{}\xspace For the first time a single trapped \pbar is used to measure the \pbar magnetic moment ${\bmμ}_{\pbar}$. The moment ${\bmμ}_{\pbar} = μ_{\pbar} {\bm S}/(\hbar/2)$ is given in terms of its spin $\mathbf{S}$ and the nuclear magneton (\muN) by $μ_{\pbar}/μ_N = -2.792\,845 \pm 0.000\,012$. 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 $μ_{\pbar}/μ_p = -1.000\,000 \pm 0.000\,005$ to 5 ppm, for a proton moment ${\hat{\mathbf{I}}¼}_p=\hat{I}{¼}_p\mathbf{S}/(\hslash /2)$, consistent with the prediction of the CPT theorem.

4 pages, 4 figures. arXiv admin note: substantial text overlap with arXiv:1201.3038