Low Energy Gamma Ray Excess Confronting a Singlet Scalar Extended Inert Doublet Dark Matter Model

TL;DR

This paper investigates a singlet extended inert doublet model to explain the gamma-ray excess from the galactic center, addressing limitations of the standard inert doublet model and aligning with experimental constraints.

Contribution

The study introduces a singlet extension to the inert doublet model that successfully accounts for the gamma-ray excess while satisfying experimental bounds.

Findings

Standard inert doublet model cannot explain the gamma-ray excess due to experimental constraints.

Singlet extended model can explain the gamma-ray excess and remains consistent with LHC and direct detection data.

Model aligns with observed dark matter relic density and Higgs search results.

Abstract

Recent study of gamma rays originating from the region of galactic centre has confirmed an anomalous $\gamma$-ray excess within the energy range 1-3 GeV. This can be explained as the consequence of pair annihilation of a 31-40 GeV dark matter into $b \bar b$ with thermal annihilation cross-section $\sigma v \sim 1.4-2.0 \times 10^{-26}~\rm{cm^3/s}$. In this work we revisit the Inert Doublet Model (IDM) in order to explain this gamma ray excess. Taking the lightest inert particle (LIP) as a stable DM candidate we show that a 31-40 GeV dark matter derived from IDM will fail to satisfy experimental limits on dark matter direct detection cross-section obtained from ongoing direct detection experiments and is also inconsistent with LHC findings. We show that a singlet extended inert doublet model can easily explain the reported $\gamma$-ray excess which is as well in agreement with Higgs search results at LHC and other observed results like DM relic density and direct detection constraints.