2HDM singlet portal to dark matter
  Higgs portal models are the most minimal way to explain the relic abundance
of the Universe. They add just a singlet that only couples to the Higgs through
a single parameter that controls both the dark matter relic abundance and the
direct detection cross-section. Unfortunately this scenario, either with scalar
or fermionic dark matter, is almost ruled out by the latter. In this paper we
analyze the Higgs-portal idea with fermionic dark matter in the context of a
2HDM. By disentangling the couplings responsible for the correct relic density
from those that control the direct detection cross section we are able to open
the parameter space and find wide regions consistent with both the observed
relic density and all the current bounds.
