Assisted freeze-out
  We explore a class of dark matter models with two dark matter candidates, only one interacts with the standard model sector. One of the dark matter is thermalized with the assistance of the other stable particle. While both stable particles contribute to the total relic density only one can elastically scatter with nuclei, thus effectively reducing the direct detection rate. 
Genevieve Belanger and Jong-Chul Park
hep-ph astro-ph.CO astro-ph.HE