Class of Higgs-portal Dark Matter models in the light of gamma-ray excess from Galactic center

Abstract

Recently the study of anomalous gamma-ray emission in the regions surrounding the galactic center has drawn a lot of attention as it points out that the excess of $\sim 1-3$ GeV gamma-ray in the low latitude is consistent with the emission expected from annihilating dark matter. The best-fit to the gamma-ray spectrum corresponds to dark matter (DM) candidate having mass in the range $\sim 31-40$ GeV annihilating into $b\bar{b}$-pair with cross-section $\langle \sigma v \rangle = (1.4-2.0)\times 10^{-26}\;\textrm{cm}^3 \textrm{sec}^{-1}$. We have shown that the Higgs-portal dark matter models in presence of scalar resonance (in the annihilation channel) are well-suited for explaining these phenomena. In addition, the parameter space of these models also satisfy constraints from the LHC Higgs searches, relic abundance and direct detection experiments. We also comment on real singlet scalar Higgs-portal DM model which is found to be incompatible with the recent analysis.