Colloquium: Matthew Bressler (U Mass)
Speaker: Matthew Bressler (U Mass)
Host: Marzia Rosati, Srimoyee Sen
Title: Updated Results from Runs 2 and 3 of the Muon g-2 Experiment at Fermilab
Abstract: Due to their relatively high mass and long lifetime, muons are an attractive probe for the potential existence of physics beyond the Standard Model. The Muon 𝑔−2 experiment studies the precession of muons’ spins as they orbit in the magnetic field of a 7.112 m radius circular storage ring, with the goal of making the most precise measurement of the so-called “anomalous” magnetic moment, namely the factor 𝑎 𝜇=𝑔𝜇−22, which arises from the muons’ interactions with virtual particles during their interaction with the magnetic field. In August 2023 the Muon 𝑔−2 collaboration released our newest result from data collected in 2019 and 2020, which included a factor of 4 more statistics than the Run-1 result from data collected in 2018 and more than a factor of 2 improvement in systematic uncertainties over the previous measurement, resulting in a total uncertainty of 0.20 ppm on the factor 𝑎 𝜇. In this talk, I will describe the principles of the 𝑔−2 measurement, discuss some of the improvements made on the systematic errors, and briefly summarize the experiment’s progress since 2020, looking ahead to the next results.