Searching for vector dark matter via Higgs portal at the LHC

A Higgs portal dark matter model for explaining the gamma ray excess from the galactic center can be realized with the extension of local SU(2)X gauge symmetry with one quadruplet. Due to the residual Z3 discrete symmetry of SU(2)X, the new gauge bosons are the stable dark matter candidates. Due to the mixture of the standard model Higgs doublet and the introduced quadruplet, dark matter could annihilate into the standard model particles through the Higgs portal and new scalar portal. We study the discovery significance of the vector dark matter at the Large Hadron Collider. The involved parameters are consistent with the constraints from relic density and direct detection and with the data of the galactic center gamma ray excess. With s=14 TeV and luminosities of 100 and 300 fb-1, we find that a discovery significance of S/B=5 can be easily reached if the production of dark matter is through the invisible decays of the Higgs boson and a new scalar boson.