Speaker
Description
The muon anomalous magnetic moment, $a_\mu=\frac{g-2}{2}$, is a low-energy observable which can be both measured and computed to high precision, making it a sensitive test of the Standard Model and a probe for new physics. The Muon g-2 experiment at Fermilab aims to measure $a_{\mu}$ with a final accuracy of 140 parts per billion (ppb). The experiment is based on the measurement of the muon spin anomalous precession frequency, $\omega_a$, using the arrival time distribution of high-energy decay positrons observed by 24 electromagnetic calorimeters, placed around the inner circumference of a $14$~m diameter storage ring. Precise knowledge of the storage ring magnetic field and of the beam time and space distribution is crucial to achieve this level of precision
The first result of the experiment, based on the 2018 data-taking campaign, was published in 2021 and it confirmed the previous result obtained at the Brookhaven National Laboratory with a similar sensitivity of 460 ppb . In this talk we present the result based on the 2019 and 2020 datasets, which contain a factor four more data, thus increasing the sensitivity to 200 ppb. We will discuss the improvement in the accuracy with respect to the 2021 result and the future prospects for the experiment.
