Possible explanation of indirect gamma ray signatures from hidden sector fermionic dark matter

TL;DR

This paper proposes a hidden fermionic dark matter model with an SU(2) gauge symmetry, exploring its viability and potential gamma ray signatures from dark matter annihilation in astrophysical regions.

Contribution

It introduces a novel dark sector model with a spontaneously broken SU(2) gauge symmetry and analyzes its implications for dark matter detection via gamma rays.

Findings

Model constraints from cosmological and collider data

Predicted gamma ray fluxes from Galactic Centre and dwarf galaxies

Potential signals consistent with observed gamma ray excesses

Abstract

We propose the existence of a hidden or dark sector besides the standard model (SM) of particle physics, whose members (both fermionic and bosonic) obey a local SU(2)$_{\rm H}$ gauge symmetry while behaving like a singlet under the SM gauge group. However, the fermiomic fields of the dark sector also possess another global U(1)$_{\rm H}$ symmetry which remains unbroken. The local SU(2)$_{\rm H}$ invariance of the dark sector is broken spontaneously when a scalar field in this sector acquires a vacuum expectation value (VEV) and thereby generating masses to the dark gauge bosons and dark fermions charged under the SU(2)$_{\rm H}$. The lightest fermion in this dark SU(2)$_{\rm H}$ sector can be a potential dark matter candidate. We first examine the viability of the model and constrain the model parameter space by theoretical constraints such as vacuum stability and by the experimental constraints such as PLANCK limit on relic density, LHC data, limits on spin independent scattering cross-section from dark matter direct search experiments etc. We then investigate the gamma rays from the pair annihilation of the proposed dark matter candidate at the Galactic Centre region. We also extend our calculations of gamma rays flux for the case of dwarf galaxies and compare the signatures of gamma rays obtained from these astrophysical sites.