2019/09/30 by Julián Calle, Diego Restrepo, Óscar Zapata
Physics and Astronomy · #Dark Matter and Cosmic Phenomena #Dirac fermion #Fermion #MAJORANA #Neutrino #Neutrino Physics Research #Neutrino oscillation #Particle physics #Particle physics theoretical and experimental studies #Physics #Sterile neutrino #hep-ph
paper · pdf · doi:10.1103/physrevd.101.035004
published as Phys. Rev. D 101, 035004 (2020) · Code available at https://github.com/restrepo/DiracMajorana 17 pages, 4 figures, 2 tables
arxiv created 2020/02/05 · openalex publication_date 2020/02/06 · arxiv updated 2020/02/12 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The radiative type-I seesaw has been already implemented to explain the lightness of Majorana neutrinos with both Majorana and Dirac heavy fermions, and the lightness of Dirac neutrinos with Dirac heavy fermions. In this work, we present a minimal implementation of the radiative type-I seesaw with light Dirac neutrinos and heavy Majorana fermions. An inert doublet and a complex singlet scalar complete the dark sector, which is protected by an Abelian fermiophobic gauge symmetry that also forbids tree level mass contributions for the full set of light neutrinos. A fermion vectorlike extension of the model is also proposed where the light right-handed neutrinos can thermalize in the primordial plasma and the extra gauge boson can be directly produced at colliders. In particular, the current upper bound on \mathrm\ensuremathΔNeff reported by PLANCK points to large ratios of M_Z^\ensuremath'/g^\ensuremath'\ensuremath\gtrsim40 TeV, which can be competitive with collider constraint for g^\ensuremath' sufficiently large in the ballpark of the Standard Model values, while future cosmic microwave background experiments may probe all the no minimal models presented here.