APS tip sheet: Origins of matter and antimatter

image: The rotation of the QCD axion (black ball) produces an excess of matter (colored balls) over antimatter, allowing galaxies and human beings to exist.

Image: 
Co et al. Physical Review Letters (2020) and NASA

The fact that the Universe has more matter than antimatter is often referred to as "baryon asymmetry." The theoretical process behind this imbalance is "baryogenesis" and supposedly took place during the early cosmos. Now, a new paper postulates a mechanism called "axiogenesis," which suggests that the excess of matter over antimatter comes from a rotation of the axion field. Raymond Co and Keisuke Harigaya used a model to explore the physics behind the rotation of the quantum chromodynamics axion, a hypothetical particle that is also a dark matter candidate. The work could provide "new research avenues for model building and studies of associated phenomenology" according to the authors.

Axiogenesis

Raymond T. Co and Keisuke Harigaya

Credit: 
American Physical Society