Saturday 01 February 2025
Scientists have long sought to understand how our universe came to be dominated by matter over antimatter, a phenomenon known as baryogenesis. One of the most promising approaches is asymmetric dark matter, where the dark sector’s asymmetry is responsible for the observed matter-antimatter imbalance. A recent paper has shed new light on this topic, offering a fresh perspective on how to achieve total asymmetry in the dark sector.
The study begins by examining Z(3)-symmetric models, which are types of particle interactions that conserve a specific symmetry called charge conjugation plus parity (CP) symmetry. The researchers found that these models can lead to matter-antimatter asymmetry from semi-annihilations, where two dark matter particles react into one dark matter antiparticle and a particle from the visible sector.
However, previous attempts at achieving asymmetric dark matter have been unsuccessful due to the S-matrix unitarity constraints. These constraints ensure that the sum of all possible interactions between particles is finite and well-defined. The researchers discovered that these constraints can be avoided by introducing more than one reaction channel in the model, allowing for a nonzero asymmetry.
The study then explores two simple Z(3)-symmetric models, each with its own unique features. In the first model, the dark matter sector consists of real scalars that interact with each other and the visible sector through feeble interactions. The researchers found that these interactions can lead to total asymmetry in the dark sector, even when the couplings are small.
In the second model, the dark matter sector is composed of Majorana fermions, which are types of particles that are their own antiparticles. These fermions interact with each other and the visible sector through higher-dimensional effective operators, which are suppressed by a high energy scale. Again, the researchers found that these interactions can lead to total asymmetry in the dark sector.
The study’s findings have significant implications for our understanding of baryogenesis and the origins of the universe. The results suggest that asymmetric dark matter may be a viable explanation for the observed matter-antimatter imbalance, and that the dark sector may play a crucial role in shaping the evolution of the universe.
In summary, scientists have long sought to understand how our universe came to be dominated by matter over antimatter. A recent paper has shed new light on this topic, offering a fresh perspective on how to achieve total asymmetry in the dark sector.
Cite this article: “Shedding Light on Asymmetric Dark Matter Models”, The Science Archive, 2025.
Dark Matter, Asymmetric Dark Matter, Baryogenesis, Z(3)-Symmetric Models, Cp Symmetry, Semi-Annihilations, S-Matrix Unitarity Constraints, Real Scalars, Majorana Fermions, High Energy Scale.
