Dark matter with exotic mediators: The diquark portal

Abstract: In this work we build out complete mediator sectors for models of frustrated dark matter (fDM), a new paradigm in which fermionic dark matter couples to the Standard Model (SM) through a scalar-fermionic mediator pair. The fDM paradigm allows great freedom in the charge assignments of the mediators: it accommodates any representation of the SM gauge group provided that the scalar and fermionic mediators have the same charges. In this paper, we write down all renormalizable models in which the mediator(s) make contact with the SM through pairs of quarks, a model space we refer to as the \emph{diquark portal}. The mediators in this portal may be singlets, triplets, sextets, or octets of the color group $\mathrm{SU}(3){\text{c}}$. The mediators may additionally be in non-trivial representations of the weak group $\mathrm{SU}(2){\text{L}}$, including doublet and triplet representations, depending on the mediators' color charge. In addition to writing the complete set of renormalizable Lagrangians, we categorize the general collider phenomenology of the models and discuss pair- and single-production LHC signatures of the mediator sectors.