  We investigate the search prospects for new scalars beyond the Standard Model
(SM) at the Large Hadron Collider (LHC). In these studies two real scalars $S$
and $\chi$ have been introduced in a two Higgs doublet model (2HDM), where $S$
is a portal to dark matter (DM) through its interaction with $\chi$, a DM
candidate and a possible source of missing transverse energy (\MET). Previous
studies focused on a heavy scalar $H$ decay mode $H \to h\chi\chi$, which was
studied using an effective theory in order to explain a distortion in the Higgs
($h$) transverse momentum spectrum [16]. In this work, the effective decay is
understood more deeply by including a mediator $S$, and the focus is changed to
$H \to h S,~SS$ with $S \to \chi\chi$. Phenomenological signatures of all the
new scalars in the proposed 2HDM are discussed in the energy regime of the LHC,
and their mass bounds have been set accordingly. Additionally, we have
performed several analyses with final states including leptons and \MET, with
$H \to 4 W$, $t\bar t H \to 6 W$ and $A \to ZH$ channels, in order to
understand the impact these scalars have on current searches.

High Energy Physics - Phenomenology