Status and Prospects from the Muon g-2 Experiment

Precision measurements of the static properties of leptons and baryons are increasingly important in an era where signatures of beyond the Standard Model (SM) physics remain conspicuously absent from experiments operating at the energy frontier. The anomalous magnetic moment of the muon a_μ= (g-2)/2 can be calculated and measured to extraordinary precision, permitting a unique sensitivity to contributions from new particles and forces. To date, the most precise measurement of a_μ, made by the E821 experiment at Brookhaven National Laboratory (BNL), disagrees with the SM calculation by more than three standard deviations. This fact has motivated the development of two new and complementary muon g-2 experiments, which are sited at Fermilab and J-PARC. Similarly, the theoretical community has made significant progress towards its goal of reducing the error on the SM prediction for a_μ by at least a factor of two.

Fermilab experiment E989 has just completed the first of several running periods, collecting a dataset that is comparable in sensitivity to the previous BNL experiment. The ultimate goal is to collect enough data to measure a_μ to 0.14 parts per million (ppm), a factor of four improvement compared to E821. The status of the analysis from the first run and a report from the front lines of the second run will be discussed.