muondecays

Muon decay is a fundamental process in particle physics where an unstable muon transforms into other particles. Muons are leptons, similar to electrons but with a greater mass. They are created in high-energy particle collisions, such as those produced by cosmic rays interacting with Earth's atmosphere, or in particle accelerators.

The most common decay mode for a muon is into an electron, an electron antineutrino, and a muon neutrino. This process is mediated by the weak nuclear force. Mathematically, this decay can be represented as:

μ⁻ → e⁻ + ν̄ₑ + ν_μ

There are also less common decay modes, such as the muon decaying into an electron, a photon, and a muon neutrino (μ⁻ → e⁻ + γ + ν_μ), or into an electron, a positron, and two neutrinos (μ⁻ → e⁻ + e⁺ + νₑ + ν̄_μ). These rarer decays provide important tests for the Standard Model of particle physics.

The average lifetime of a muon is very short, approximately 2.2 microseconds. This short lifetime, despite being much longer than that of many other unstable particles, is long enough for muons created in the atmosphere to reach the Earth's surface, making them detectable and useful for experiments like muon tomography. The study of muon decay has been crucial in understanding fundamental forces and the properties of elementary particles.