Y Minimal asymptotically safe dark matter

We study a simple class of dark matter models with N-f copies of electroweak fermionic multiplets, stabilized by O(N-F) global symmetry. Unlike conventional minimal dark matter which usually suffers from Landau poles, in these models the gauge coupling g(2) has a non-trivial ultraviolet fixed point, and thus is asymptotically safe as long as N-F is large enough. These fermionic n-plet models have only two free parameters: N-F and a common mass M-DM, which relate to dark matter relic abundance. We find that the mass of triplet fermionic dark matter with N-F similar to O(10) flavors can be several hundred GeV, which is testable on LHC. A benefit of large N-F is that DM pair annihilation rate in dwarf galaxies is effectively suppressed by 1/N-F, and thus they can evade the constraint from gamma-ray continuous spectrum observation. For the case of triplets, we find that the models in the range 3 <= N-F <= 20 are consistent with all current experiments. However, for N-F quintuplets, even with large NF they are still disfavored by the gamma-ray continuous spectrum. (C) 2019 The Authors. Published by Elsevier B.V.