A New Measurement of the Muon Magnetic Anomaly

The muon anomalous magnetic moment, $a_\mu = (g-2)/2$, is a low-energy observable which can be both measured and computed with very high precision, making it an excellent test of the Standard Model (SM) and a sensitive probe of new physics. Recent efforts improved the precision of both the theoretical prediction and the experimental measurement. On the theory side, the Muon $g-2$ Theory Initiative, an international team of more than 130 physicists, reached in 2020 a consensus...

The E989 Muon $g-2$ Experiment at Fermilab aims to measure the muon magnetic anomaly, $a_\mu$, to an unprecedented precision of 140 parts per billion (ppb), representing a four-fold improvement over the current best measurement, achieved at Brookhaven National Lab. There stands a greater than 3 standard deviations discrepancy between the Brookhaven measurement of $a_\mu$ and the theoretical value predicted using the Standard Model. The Fermilab experiment seeks to either reso...

The experimental method together with the analysis method and results of the data taken in 2000 and prospects of the muon anomalous magnetic and electric dipole moment experiments are presented here.

I review the present Standard Model prediction of the muon anomalous magnetic moment. The discrepancy with its experimental determination is (25.5 +- 8.0) x 10^-10, i.e., 3.2 standard deviations.

The muon magnetic anomaly, $a_{\mu}=(g_{\mu}-2)/2$, plays a special role in the history of the Standard Model (SM). Precise calculations and measurements of this fundamental quantity provide a stringent test of the SM and a window to the physics beyond. In light of the first result published by the Fermilab Muon $g-2$ experiment, this article reviews the current status of the experimental measurement and theoretical prediction of the muon anomalous magnetic moment. It also pr...

The Muon (g-2) Experiment, E989 at Fermilab, will measure the muon anomalous magnetic moment a factor-of-four more precisely than was done in E821 at the Brookhaven National Laboratory AGS. The E821 result appears to be greater than the Standard-Model prediction by more than three standard deviations. When combined with expected improvement in the Standard-Model hadronic contributions, E989 should be able to determine definitively whether or not the E821 result is evidence fo...

The New Muon $(g-2)$ Collaboration at Fermilab has proposed to measure the anomalous magnetic moment of the muon, $a_\mu$, a factor of four better than was done in E821 at the Brookhaven AGS, which obtained $a_\mu = [116 592 089 (63)] \times 10^{-11}$ $\pm 0.54$ ppm. The last digit of $a_{\mu}$ is changed from the published value owing to a new value of the ratio of the muon-to-proton magnetic moment that has become available. At present there appears to be a difference betwe...

A review of the theoretical and experimental values for the charged lepton (electron and muon) anomalous magnetic moment $a_l= (g_l-2)/2$ is presented. Employing the most accurate value for the fine structure constant $\alpha^{-1}= 137.03599993(52) (0.0038 ppm)$ obtained \cite {Kin196} from the electron $(g-2)$ we find the new complete standard model prediction for the anomalous magnetic moment of the muon $a^{th}_{\mu}= 116591595(67)\times 10^{-11}$. The comparison of this t...

We discuss the prospects for improving the precision on the hadronic corrections to the anomalous magnetic moment of the muon, and the plans of the Muon $g-2$ Theory Initiative to update the Standard Model prediction.

A new measurement of the anomalous magnetic moment of the muon, $a_{\mu} \equiv (g-2)/2$, will be performed at the Fermi National Accelerator Laboratory with data taking beginning in 2017. The most recent measurement, performed at Brookhaven National Laboratory (BNL) and completed in 2001, shows a 3.5 standard deviation discrepancy with the standard model value of $a_\mu$. The new measurement will accumulate 21 times the BNL statistics using upgraded magnet, detector, and sto...