Mitigating Direct Detection Bounds in Non-minimal Higgs Portal Scalar
  Dark Matter Models
  Minimal scalar Higgs portal dark matter model is increasingly in tension with
recent results form direct detection experiments like LUX and XENON. In this
paper we make a systematic study of minimal extension of the $ \mathbb{Z}_2$
stabilised singlet scalar Higgs portal scenario in terms of their prospects at
direct detection experiments. We consider both enlarging the stabilising
symmetry to $\mathbb{Z}_3$ and incorporating multipartite features in the dark
sector. We demonstrate that in these non-minimal models the interplay of
annihilation, co-annihilation and semi-annihilation processes considerably
relax constraints from present and proposed direct detection experiments while
simultaneously saturating observed dark matter relic density. We explore in
particular the resonant semi-annihilation channel within the multipartite
$\mathbb{Z}_3$ framework which results in new unexplored regions of parameter
space that would be difficult to constrain by direct detection experiments in
the near future. The role of dark matter exchange processes within
multi-component $\mathbb{Z}_3 \times \mathbb{Z}_3'$ framework is illustrated.
We make quantitative estimates to elucidate the role of the various
annihilation processes in the different allowed regions of parameter space of
these models.
