Why the annihilation must be between a couple of particle and counterpart antipartic?

[ndung200790]

Please teach me about this:
Why the annihilation between particles must be particle and coresponding anti particle.Example:electron can annihilate positron create a virtual photon,after that,virtual photon create a couple muyon and antimuyon.But why can't be there exist the annihilation between electron and muyon to create avirtual photon or annihilation between electron and antimuyon to create a virtual photon after that virtual photon create positron and muyon.
Thank you very much in advance

 

[HallsofIvy]

All of the various "quantum numbers" (charge, spin, strangeness, etc.) have to be conserved. You can only annihilate a particle with a particle having the opposite of every quantum number- and that, by definition, is its "anti-particle".