The muon is one of the fundamental building blocks of subatomic particles. It shares the same electric charge as an electron, but is about 200 times heavier. Its initial discovery prompted I.I. Rabi to quip, “Who ordered that?”
The muon is back in the news again because of its quantum interactions with electricity and magnetism and its anomalous magnetic moment, or simply “g-2” (pronounced “g minus 2”). Recent experiments seem to indicate a discrepancy with theoretical calculations of g-2 based on the Standard Model of particle physics, our current best understanding of how Nature works at the microscopic level. This is also in stark contrast to what happens with the electron, where there is still a remarkable agreement between theory and experiment.
In this seminar we discuss how the measurement of g-2 provides a window into the search for new particles and fundamental forces, and the potential implications of the recent discrepancies between theory and experiment.
(Image by Glukicov, CC BY-SA 4.0)