Non-thermal Dark Matter in $U(1)_{B-L}$ Extension of Inert Doublet Model

TL;DR

This paper extends the Inert Doublet Model with a $U(1)_{B-L}$ symmetry to generate neutrino masses and explain dark matter through non-thermal production, aligning theoretical predictions with experimental observations.

Contribution

It introduces a $U(1)_{B-L}$ extension that enables non-thermal dark matter production and neutrino mass generation within the inert doublet framework.

Findings

Non-thermal production can yield correct dark matter relic abundance.

The model is consistent with current direct and indirect detection constraints.

Heavy scalar decay provides a viable mechanism for dark matter relic density.

Abstract

We propose an extension of the Inert Doublet Model (IDM) that explains both neutrino masses and dark matter (DM) in the intermediate-mass range by incorporating a $U(1)_{B-L}$ gauge symmetry. This additional symmetry enables the inclusion of right-handed neutrinos, providing a natural mechanism for neutrino mass generation. While the CP-even component of the inert doublet can serve as a DM candidate, its thermal relic abundance is insufficient to match the observed DM density. To address this, we introduce a non-thermal production mechanism, where a heavy scalar associated with the $U(1)_{B-L}$ symmetry decays into the inert doublet scalar, yielding a viable relic abundance at low reheating temperatures. We also examine both direct and indirect detection prospects for this DM candidate and assess the model against current experimental constraints.