Exploring Spin-3/2 Dark Matter with Effective Higgs Couplings

We study an economical model of weakly-interacting massive particle dark matter (DM) which has spin 3/2 and interacts with the 125-GeV Higgs boson via effective scalar and pseudoscalar operators. We apply constraints on the model from the relic density data, LHC measurements of the Higgs boson, and direct and indirect searches for DM, taking into account the effective nature of the DM-Higgs couplings. We find that this DM is currently viable in most of the mass region from about 58 GeV to 2.3 TeV and will be probed more stringently by ongoing and upcoming experiments. Nevertheless, the presence of the DM-Higgs pseudoscalar coupling could make parts of the model parameter space elusive from future tests. This scenario is quite similar to its more popular spin-1/2 counterpart.