Unraveling the Scotogenic model at muon collider
Jiao Liu (School of Physics and Technology, University of Jinan, Jinan, Shandong, 250022, China, Guangxi Key Laboratory of Nuclear Physics and Nuclear Technology, Guangxi Normal University, Guilin, Guangxi, 541004, China); Zhi-Long Han (School of Physics and Technology, University of Jinan, Jinan, Shandong, 250022, China); Yi Jin (School of Physics and Technology, University of Jinan, Jinan, Shandong, 250022, China, Guangxi Key Laboratory of Nuclear Physics and Nuclear Technology, Guangxi Normal University, Guilin, Guangxi, 541004, China); Honglei Li (School of Physics and Technology, University of Jinan, Jinan, Shandong, 250022, China)
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 $$ \mid {y}_{1e}\mid \ll \mid {y}_{1\mu}\mid \sim \mid {y}_{1\tau}\mid \sim \mathcal{O}(1) $$ 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 ≲ $$ {M}_{\eta^{\pm }} $$ . Masses of charged scalar η ± and dark matter N 1 can be further extracted by a binned likelihood fit of the dilepton energy.
