Muon decay is a fundamental process in particle physics governed by the weak nuclear interaction, one of the four fundamental forces of nature. A muon (μ⁻), which is similar to an electron but about 200 times more massive, is an unstable elementary particle with a mean lifetime of about 2.2 microseconds.
How Muon Decay Works:
- A muon decays into three particles:
- An electron (e⁻)
- An electron antineutrino (ν̄ₑ)
- A muon neutrino (ν_μ)
- This decay conserves energy, charge, and lepton numbers, and proceeds via the exchange of a W boson, the mediator of the weak force.
Importance of Studying Muon Decay:
- It provides deep insight into the structure of the weak interaction and how it differs from electromagnetic or strong forces.
- Precise measurements of muon decay parameters help test the Standard Model of particle physics, including the universality of lepton interactions.
- Deviations from expected decay patterns could indicate new physics beyond the Standard Model, such as supersymmetry or lepton flavor violation.
Applications:
- Muon decay is used in experiments to measure the Fermi coupling constant (G_F), which defines the strength of weak interactions.
- It plays a role in muon lifetime experiments and muon g−2 studies, which search for discrepancies between theory and observation.
Muon decay remains one of the cleanest and most informative processes for exploring the fundamental symmetries of the universe.