The anomalous magnetic moment of the muon, and the Beijing Spectrometer experiment

The latest experimental measurements of the anomalous magnetic moment of the muon deviates from the theoretical prediction by 4.2 sigma, which provides essential evidence for the existence of new physics beyond the Standard Model. To confirm this, however, further improvements in the precision for both experimental measurements and theoretical predictions are necessary. The Beijing Spectrometer experiment at the Beijing Electron-Positron Collider facility, operating in the transition energy range between perturbative and non-perturbative quantum chromodynamics, is an ideal playground for the study of strong interactions in the low energy region; it is an important contributor to the theoretical prediction of the anomalous magnetic moment by providing a stringent constraint on the dominant theoretical uncertainty——the hadronic vacuum polarization. In this paper, the current status of experimental measurements and theoretical prediction are reviewed, and future expectations are assessed.