Muon

A muon (μ) is an elementary particle with unit electric charge and a mass of about 106 MeV/c². Muons have a mean lifetime of about 2.2 μs and decay primarily into electrons and neutrinos.

Particle properties

Muons are elementary particles which interact graviationally, electromagnetically and weakly. The particles do not undergo strong interactions, owing to their half-integer spin. The mass of muons is about 106 MeV/c², making them about 207 times heavier than electrons.

Muons have unit electric charge. Conventionally, muons (μ^-) are considered to carry a negative charge, while their anti-matter counterparts (anti-muons or μ⁺) are positively charged. The weak interaction mediates the decay of muons. As weak processes can be considered slow on typical sub-atomic timescales, the muons exhibit a mean lifetime of about 2.2 μs. The most common decay products are electrons and neutrinos.

Interactions	Gravity, Electromagnetic, Weak
Mass	105.6583755(23) MeV/c2
Mean lifetime	2.1969811(22) x 10-6 s
Electric charge	1
Spin	1/2

Muons in cosmic showers

Muons appear in cosmic showers as secondary shower particles. Owing to their finite lifetime, the mean path of muonic shower particles is limited. Classically, one $s=vt$