Muon, << MYOO on, >> is a type of elementary particle that closely resembles an electron but has a greater mass. An elementary particle does not consist of smaller units. Both muons and electrons belong to a family of such particles called leptons. The muon carries a negative charge like an electron, but it is about 207 times heavier. Muons are unstable, and so they decay (break down) to form electrons and other lighter particles.
The muon was discovered independently by two groups of scientists in 1937. These groups were Carl D. Anderson and Seth H. Neddermeyer of California Institute of Technology and Jabez C. Street and Edward C. Stevenson of Harvard University. Scientists have learned about magnetic fields in certain substances by observing muon decay in those materials.
