negative muon

from WordNet (r) 3.0 (2006)

negative muon
    n 1: an elementary particle with a negative charge and a half-
         life of 2 microsecond; decays to electron and neutrino and
         antineutrino [syn: {muon}, {negative muon}, {mu-meson}]

from The Collaborative International Dictionary of English v.0.48

lepton \lepton\ n. (Physics)
   an elementary particle that participates in weak interactions
   but does not participate in the strong interaction; it has a
   baryon number of 0. Some known leptons are the {electron},
   the {negative muon}, the {tau-minus particle}, and the
   neutrinos associated with each of these particles.
   [WordNet 1.5 +PJC]