Two-Component Dark Matter

Understand

We study an extension of the Standard Model (SM) with two interacting cold Dark Matter (DM) candidates: a neutral Majorana fermion ($\nu$) and a neutral scalar singlet ($\varphi$).

• The scalar $\varphi$ interacts with the SM through the "Higgs portal" coupling while $\nu$ at the tree level interacts only with $\varphi$ through Yukawa interactions.
• The relic abundance of $\nu$ and $\varphi$ is found by solving the Boltzmann equations numerically; for the case $m_\nu > m_\varphi$ we also derive a reliable approximate analytical solution.
• Effects of the interaction between the two DM components are discussed.