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We investigate a neutral gauge boson X originated from a hidden U(1) extension of the standard model as the particle dark matter candidate. The vector dark matter interacts with the standard model fermions through heavy fermion mediators. The interactions give rise to t-channel annihilation cross section in the XX to ff process, which dominates the thermal relic abundance during thermal freeze-out and produces measurable gamma-ray flux in the galactic halo. For a light vector dark matter, if it predominantly couples to the third generation fermions, this model could explain the excess of gamma rays from the galactic center. We show that the vector dark matter with a mass of 20 ~ 40 GeV and that annihilate into the bb and tautau final states provides an excellent description of the observed gamma-ray excess. The parameter space aimed at explaining the gamma-ray excess, could also provide the correct thermal relic density and is compatible with the constraints from electroweak precision data, Higgs invisible decay, and collider searches. We also show the dark matter couplings to the nucleon from the fermion portal interactions are loop-suppressed, and only contribute to the spin-dependent cross section. So the vector dark matter could easily escape the stringent constraints from the direct detection experiments.
We consider a simple extension of the type-II two-Higgs-doublet model by introducing a real scalar as a candidate for dark matter in the present Universe. The main annihilation mode of the dark matter particle with a mass of around $31-40$ GeV is int
We show that the Galactic Center Excess (GCE) emission, as recently updated by the Fermi-LAT Collaboration, could be explained by the sum of Fermi-bubbles-like emission plus dark matter (DM) annihilation, in the context of a scalar-singlet Higgs port
The singlet-doublet fermion dark matter model (SDFDM) provides a good DM candidate as well as the possibility of generating neutrino masses radiatively. The search and identification of DM requires the combined effort of both indirect and direct DM d
We work with a UV conformal U(1) extension of the Standard Model, motivated by the hierarchy problem and recent collider anomalies. This model admits fermionic vector portal WIMP dark matter charged under the U(1) gauge group. The asymptotically safe
The Fermi Large Area Telescope observed an excess in gamma ray emission spectrum coming from the center of the Milky Way galaxy. This data reveals that a light Dark Matter (DM) candidate of mass in the range 31-40 GeV, dominantly decaying into $bbar