| This theory should also apply to the muon and tauon and corresponding antiparticles. |
| Antimatter is matter composed of antiparticles, such as positrons, antineutrons and antiprotons. |
| Note that subatomic particles sometimes have antiparticles, with opposite charge and spin, that are the same ones going backwards in time. |
| At the subatomic level, for example, particles should behave like their alter egos, called antiparticles. |
| At about one second into the life of the universe, the majority of existing particles and antiparticles had been destroyed to produce photons of electromagnetic radiation. |
| Positrons, antiprotons and other antiparticles can be routinely created at particle accelerator labs and can even be trapped and stored for days or weeks at a time. |
