Main Question or Discussion Point
I've been searching about particle-antiparticle annihilation and I've been wondering whether it was possible for particle to annihilate with antiparticle that is not its pair? Can annihilation occur with collision of different particle-antiparticle quarks(e.g. up antiquark and strange quark), with different particle-antiparticle leptons(e.g. electron antineutrino and muon) or with particle-antiparticle quark and lepton(e.g. bottom quark and antitau)?