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A '''muon''' (μ) is an elementary particle with unit electric charge and a mass of about 106 MeV/c<sup>2</sup>. Muons have a mean lifetime of about 2.2 μs and decay primarily into electrons and neutrinos. 

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== 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/c<sup>2</sup>, making them about 207 times heavier than electrons.
 
Muons have unit electric charge. Conventionally, muons (μ<sup>-</sup>) are considered to carry a negative charge, while their anti-matter counterparts (anti-muons or μ<sup>+</sup>) 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. 

{| class="wikitable"
|-
| Interactions || Gravity, Electromagnetic, Weak
|-
| Mass || 105.6583755(23) MeV/c<sup>2</sup>
|-
| Mean lifetime || 2.1969811(22) x 10<sup>-6</sup> 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 
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