Asymmetric Dark Matter

Abstract

We consider a simple class of models in which the relic density of dark matter is determined by the baryon asymmetry of the universe. In these models a $B-L$ asymmetry generated at high temperatures is transfered to the dark matter, which is charged under $B-L$. The interactions that transfer the asymmetry decouple at temperatures above the dark matter mass, freezing in a dark matter asymmetry of order the baryon asymmetry. This explains the observed relation between the baryon and dark matter densities for dark matter mass in the range 5--15 GeV. The symmetric component of the dark matter can annihilate efficiently to light pseudoscalar Higgs particles $a$, or via $t$-channel exchange of new scalar doublets. The first possibility allows for $h^0\to aa$ decays, while the second predicts a light charged Higgs-like scalar decaying to $\tau \nu$. Direct detection can arise from Higgs exchange in the first model, or a nonzero magnetic moment in the second. In supersymmetric models, the would-be LSP can decay into pairs of dark matter particles plus standard model particles, possibly with displaced vertices.

22 pages, no figures

References in corpus (9)

• First results from DAMA/LIBRA and the combined results with DAMA/NaI
• Nonstandard Higgs Boson Decays
• Unified origin of baryons and dark matter
• DAMA and WIMP dark matter
• Using the Energy Spectrum at DAMA/LIBRA to Probe Light Dark Matter
• The New DAMA Dark-Matter Window and Energetic-Neutrino Searches
• Compatibility of DAMA/LIBRA dark matter detection with other searches in light of new Galactic rotation velocity measurements
• Zooming in on light relic neutralinos by direct detection and measurements of galactic antimatter
• Axino warm dark matter and ${\Omega }_b-{\Omega }_{DM}$ coincidence

Cited by in corpus (4)

• Multi-Component Dark Matter
• Right-handed sneutrino dark matter in the NMSSM
• Dark Matter Through the Neutrino Portal
• Visible and Dark Matter Genesis and Cosmic Positron/Electron Excesses