Tensor Dark Matter

Abstract

In this work we propose an alternative explanation to the nature of dark matter which consists of an unconventional space-time structure of fields transforming in the (1,0)+(0,1) representation of the Homogeneous Lorentz Group (HLG), which we call Tensor Dark Matter (TDM). We review this spinor-like formalism and use it to describe free dark matter fields establishing the corresponding effective field theory for interactions with standard model fields. We calculate the decay widths of Z and Higgs bosons into TDM, compare the results with the invisible width limits for these bosons and find a relation between the mass of the TDM field and the values of the coupling constants. Then, we calculate the relic abundance and obtain bounds on the mass and the couplings of TDM from the observed value of the dark matter relic density. From direct detection bounds set by XENON1T data we find that the spin-portal coupling is severely constrained. Comparing with indirect detection limits, we find that the Gamma-Ray Excess in the Galaxy Center can be explained by TDM annihilation with a scalar coupling to the Higgs between [0.98x10^(-3),1.01x10^(-3)] and M between [62.470,62.505] GeV. This is consistent with indirect detection bounds of DM annihilation into muons, taus, photons and b-quarks. We show that TDM annihilation into antiprotons from cosmic rays improves the fit to the Antiproton-Proton ratio from the AMS-02 data. Motivated by our prediction that these observables can be explained by a TDM field with M approximately equal to half the mass of the Higgs, and the fact that the leading terms in the interaction Lagrangian are dimension-four, we explore the possibility of DM interactions coming from a dark gauge structure, by including a dark gauge group that involves a factor U(1)_d subgroup that mixes kinetically with the U(1)_Y of the standard model.