The Muon g-2 Fermilab experiment (FNAL E989) plans to measure the muon anomalous magnetic moment with a precision of 0.14 parts per million, about 4 times better than the present world-average (dominated by the result of the BNL E821 experiment). The aim is to compare this measurement with the Standard Model prediction, which has a precision comparable to the present experimental one, and differs from the experimental value by about 3σ.
The E989 collaboration includes several participating Italian research institutions, which have the task to design, construct and operate the laser calibration system for the experiment electro-magnetic calorimeter. This system precisely monitors the gain the calorimeter, whose understanding corresponds to a significant systematic uncertainty of the measurement. With respect to the BNL experiment, the Fermilab experiment plans to reduce this sistematic contribution from 120 parts per billion to 20 parts per billion, the largest planned reduction of any single systematic contribution.