The measurement of the muonʹs anomalous magnetic moment isnʹt

Recent results announced as measurements of the muonʹs anomalous magnetic moment are in fact measurements of the muonʹs anomalous spin precession frequency. This precession frequency receives contributions from both the muonʹs anomalous magnetic and electric dipole moments. We note that all existing data cannot resolve this ambiguity, and the current deviation from standard model predictions may equally well be interpreted as evidence for new physics in the muonʹs anomalous magnetic moment, new physics in the muonʹs electric dipole moment, or both.