Precise Measurement of the Positive Muon Anomalous Magnetic Moment

A precise measurement of the anomalous $g$ value, $a_{\mu }=(g-2\mathrm{})/2$, for the positive muon has been made at the Brookhaven Alternating Gradient Synchrotron. The result $a_{{\mu }^{+}}=11\mathrm{}659202\left(14\right)\left(6\right)\times {10}^{-10\mathrm{}}$ (1.3 ppm) is in good agreement with previous measurements and has an error one third that of the combined previous data. The current theoretical value from the standard model is $a_{\mu }\left(\mathrm{SM}\right)=11\mathrm{}659159.6\left(6.7\right)\times {10}^{-10\mathrm{}}$ (0.57 ppm) and $a_{\mu }\left(\exp \right){-a}_{\mu }\left(\mathrm{SM}\right)=43\mathrm{}\left(16\right)\times {10}^{-10\mathrm{}}$ in which $a_{\mu }\left(\exp \right)$ is the world average experimental value.