2016/11/10 by Wenbin Lu, Wen-Bin Lu, Pei-Hong Gu
Physics and Astronomy · #Astrophysics #Baryon asymmetry #Cosmology #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #Dark energy #Dark matter #Fermion #Hypercharge #Leptogenesis #Lepton #Neutrino #Nuclear physics #Particle physics #Particle physics theoretical and experimental studies #Physics #Scalar (mathematics) #Scalar field dark matter #Warm dark matter #hep-ph
paper · pdf · doi:10.1016/j.nuclphysb.2017.09.005
38 pages, 23 figures, typos are corrected and references are added
arxiv created 2016/11/10 · openalex publication_date 2017/09/08 · arxiv updated 2018/03/14 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
The neutral component of an inert scalar multiplet with hypercharge can provide a stable dark matter particle when its real and imaginary parts have a splitting mass spectrum. Otherwise, a tree-level dark-matter-nucleon scattering mediated by the Z boson will be much above the experimental limit. In this paper we focus on a mixed inert scalar triplet dark matter scenario where a complex scalar triplet with hypercharge can mix with another real scalar triplet without hypercharge through their renormalizable coupling to the standard model Higgs doublet. We consider three specified cases that carry most of the relevant features of the full parameter space: (i) the neutral component of the real triplet dominates the dark matter particle, (ii) the neutral component of the complex triplet dominates the dark matter particle; and (iii) the neutral components of the real and complex triplets equally constitute the dark matter particle. Subject to the dark matter relic abundance and direct detection constraint, we perform a systematic study on the allowed parameter space with particular emphasis on the interplay among triplet-doublet terms and gauge interactions. In the presence of these mixed inert scalar triplets, some heavy Dirac fermions composed of inert fermion doublets can be utilized to generate a tiny Majorana neutrino mass term at one-loop level and realize a successful leptogenesis for explaining the cosmic baryon asymmetry.