Minimal asymptotically safe dark matter

Abstract

We study a simple class of dark matter models with Nf copies of electroweak fermionic multiplets, stabilized by O(NF) global symmetry. Unlike conventional minimal dark matter which usually suffers from Landau poles, in these models the gauge coupling g2 has a non-trivial ultraviolet fixed point, and thus is asymptotically safe as long as NF is large enough. These fermionic n-plet models have only two free parameters: NF and a common mass MDM, which relate to dark matter relic abundance. We find that the mass of triplet fermionic dark matter with NF∼O(10) flavors can be several hundred GeV, which is testable on LHC. A benefit of large NF is that DM pair annihilation rate in dwarf galaxies is effectively suppressed by 1/NF, and thus they can evade the constraint from γ-ray continuous spectrum observation. For the case of triplets, we find that the models in the range 3≤NF≤20 are consistent with all current experiments. However, for NF quintuplets, even with large NF they are still disfavored by the γ-ray continuous spectrum.