particle-antiparticle
Noun
Meaning
particle-antiparticle (plural particle-antiparticles)
Oppositely charged particle with opposite quantum numbers.
Examples
As the Universe expanded and cooled, the average thermal energy of these lighter particles decreased and eventually became insufficient to form a dark matter particle-antiparticle pair.
The annihilation of the dark matter particle-antiparticle pairs, however, would have continued, and the number density of dark matter particles would have begun to decrease exponentially.
This is the inverse of the particle-antiparticle annihilation process.