Unraveling the Scotogenic model at muon collider

Abstract

Abstract The Scotogenic model extends the standard model with three singlet fermion N i and one inert doublet scalar η to address the common origin of tiny neutrino mass and dark matter. For fermion dark matter N 1, a hierarchical Yukawa structure ∣ y 1 e ∣ ≪ ∣ y 1 μ ∣ ∼ ∣ y 1 τ ∣ ∼ O 1 $$ \mid {y}_{1e}\mid \ll \mid {y}_{1\mu}\mid \sim \mid {y}_{1\tau}\mid \sim \mathcal{O}(1) $$ is usually favored to satisfy constraints from lepton flavor violation and relic density. Such large μ-related Yukawa coupling would greatly enhance the pair production of charged scalar η ± at the muon collider. In this paper, we investigate the dilepton and mono-photon signature of the Scotogenic model at a 14 TeV muon collider. For the dimuon signature , we find that most viable samples can be probed with 200 fb −1 data. The ditau signature is usually less promising, but it is important to probe the small |y 1μ | region. The mono-photon signature could also probe the compressed mass region M 1 ≲ M η ± $$ {M}_{\eta^{\pm }} $$ . Masses of charged scalar η ± and dark matter N 1 can be further extracted by a binned likelihood fit of the dilepton energy.

Keywords

• Dark Matter at Colliders
• Particle Nature of Dark Matter