antimuon

But these were expected to decay very rapidly and the observed electrons and muons were therefore interpreted as products of decay from reactions: tau - electron (or muon) + neutrinos antitau - antimuon (or positron) + neutrinos

Press Release: The 1995 Nobel Prize in Physics 1995

The first indication of a possible new phenomenon was that the research team observed 24 events of the type electron + positron - electron + antimuon + i.p. or electron + positron - positron + muon + i.p. where i.p. stands for invisible particles; those that left no trace in the detector.

Press Release: The 1995 Nobel Prize in Physics 1995

The actual detection was thus only that of an electron (positron) and an antimuon (muon), i.e., two different leptons with opposite charges, which apparently violates the law of lepton number conservation.

Additional background material on the Nobel Prize in Physics 1995 1995

And places where the spouts once were are going to look much the same, except for very specific muon and antimuon decays—assuming we can catch any of the particles in question decaying.

Dark Mirror Diane Duane 1993

(or positron) and an antimuon (or muon) with the opposite sign on its charges were detected.

Press Release: The 1995 Nobel Prize in Physics 1995