Related papers: Type-3/2 Seesaw Mechanism
Right-handed neutrinos $N$ are introduced to explain the origin of the tiny neutrino masses via the seesaw mechanism. Required by relatively large Yukawa coupling and leptogenesis, masses of right-handed neutrinos are beyond $10^{9}$ GeV.…
We consider the phenomenology of the gauged abelian symmetry B + 3 (L_e - L_mu - L_tau). Right-handed neutrinos necessary to cancel triangle anomalies are used in a type-I seesaw scheme to create active neutrino masses. Breaking the B + 3…
A minimal extension of the Standard Model is proposed, where the observed left-handed neutrinos obtain naturally small Majorana masses from a one-loop radiative seesaw mechanism. This model has two candidates (one bosonic and one fermionic)…
Dominance of type-II seesaw mechanism for neutrino masses has attracted considerable attention because of a number of advantages. We show a novel approach to achieve Type-II seesaw dominance in non-supersymmetric $SO(10)$ grand unification…
In this paper we review some mechanisms that provide light neutrinos in the framework of 3-3-1 gauge models without exotic leptons. In regard to the minimal 3-3-1 model, we call the attention to the fact that the perturbative regime of the…
The type I seesaw mechanism is one of the leading proposed explanations for how neutrinos acquire their tiny masses. However, the mass scale of the undiscovered right-handed neutrinos required by this mechanism remains undetermined.…
Recent experimental results have reported mild deviations from Standard Model predictions in processes involving two photons in the final state, suggesting the possible presence of high-mass scalar resonances at the few-hundred-GeV scale.…
The theory that the extra-space component of the gauge field is identified with the standard model Higgs boson, is called the gauge-Higgs unification (GHU) scenario. We examine how the small neutrino masses are naturally generated in the…
We show that the anomalous magnetic moment experimental data of muon and electron $(g-2)_{\mu,e}$ can be explained simultaneously in simple extensions of the 3-3-1 models consisting of new heavy neutrinos and a singly charged Higgs boson.…
We investigate Type-I Seesaw models where the right-handed neutrino masses are dynamically generated by strong interactions. Using horizontal gauge symmetry as the source of strong dynamics, a nontrivial flavor structure can also be…
We discuss the prospects for detecting right-handed neutrinos which are introduced in the see-saw mechanism at future colliders. This requires a very accurate cancellation between contributions from different right-handed neutrinos to the…
A natural extension of the standard $SU(2)_{\rm L} \times U(1)_{\rm Y}$ gauge model to accommodate massive neutrinos is to introduce one Higgs triplet and three right-handed Majorana neutrinos, leading to a $6\times 6$ neutrino mass matrix…
We investigate the low-energy phenomenology of the Type-I seesaw mechanism within a 3+3 framework containing three active and three sterile neutrinos. Using the exact seesaw relation as a bridge between the high-scale sterile-sector…
The right-handed neutrinos within the type-I seesaw mechanism can induce large radiative corrections to the Higgs mass, and naturalness arguments can then be used to set limits on their mass scale and Yukawa couplings. Driven by minimality,…
The seesaw and leptogenesis commonly depend on the masses of same particles, and thus are both realized at the same scale. In this work, we demonstrate a new possibility to realize a TeV-scale neutrino seesaw and a natural high-scale…
We discuss phenomenology of the radiative seesaw model in which spontaneous breaking of the U(1)$_{B-L}$ gauge symmetry at the TeV scale gives the common origin for masses of neutrinos and dark matter (Kanemura et al., 2012). In this model,…
We consider a version of the low-scale type I seesaw mechanism for generating small neutrino masses, as an alternative to the standard seesaw scenario. It involves two right-handed (RH) neutrinos $\nu_{1R}$ and $\nu_{2R}$ having a Majorana…
We point out that the type III seesaw mechanism introducing fermion triplets predicts peculiar Higgs boson signatures of displaced vertices with two b jets and one or two charged particles which can be cleanly identified. In a…
We consider the low energy constraints that can be applied to type I see-saw extensions of the Standard Model in which the right-handed neutrinos are taken at the electroweak scale. In the reported scenarios, the flavour structure of the…
The simplest possibility to generate small Majorana neutrino masses is the seesaw mechanism. However, the smallness of the observed neutrino masses can also be understood, if neutrino masses are generated by higher-dimensional operators…