Interplay of Scalar and Fermionic Components in a Multi-component Dark Matter Scenario

TL;DR

This paper investigates a multi-component dark matter model with scalar and fermionic candidates, demonstrating compatibility with relic density and detection constraints across a broad mass range through detailed parameter space analysis.

Contribution

It introduces a novel multi-component dark matter scenario with an inert scalar doublet and a singlet fermion, expanding viable mass regions beyond standard models.

Findings

Light DM and intermediate mass regions are compatible with relic and detection bounds.

Sizable parameter space exists for DM masses from 10 GeV to 2000 GeV.

Charged fermionic fields enable exploration of previously disallowed mass regions.

Abstract

We explore the multi-component dark matter (DM) scenario considered in a simple extension of the standard model with an inert scalar doublet and a singlet fermionic field providing the two DM candidates. The DM states are made stable under the unbroken $Z_2\times Z_2'$ discrete symmetry. An additional gauge singlet scalar field is introduced to facilitate the interaction of the dark fermion with the visible sector. Presence of a charged fermionic field having the same $Z_2$ charge as that of the inert scalar field allows exploring the dark matter mass regions otherwise disallowed, like in the standard Inert Doublet Model (IDM) scenarios. With these arrangements, it is shown that the light DM scenario and the desert region in the intermediate mass range of DM in the standard IDM case can be made compatible with the relic density bounds and direct detection limits. Further, detailed parameter space study is carried out keeping the coexistence of both the scalar and fermionic components in focus, showing that sizable parameter space regions are available for the entire mass range of $10\ \rm GeV \le M_{DM}\le 2000$ GeV.