Particle Physics Aspects

In this chapter we discuss the properties of the muon as an elementary lepton particle. We describe in detail the theoretical treatment of muon decay within the quantum field theory of the electroweak interaction, and show how the understanding of the weak interaction has evolved over time. In addition, we discuss precision experiments (such as the measurement of the muon lifetime, the determination of the muon magnetic anomaly called g-2) that underscore the importance of the muon in particle physics for the determination of fundamental constants, for testing the predictions of the Standard Model, and for the search for putative new particles or forces.