Muons

A muon (μ) is a heavy electron.The rest mass is 200 times the rest mass of an electron. A muon is negatively charged.
A muon decays into an electron, an electron antineutrino and a muon neutrino.An antimuon decays into a positron, an electron neutrino and a muon antineutrino.

μ^-   →   e^- + anti-ν_e + ν_μ

μ⁺   →   e⁺ + ν_e + anti-ν_μ