Related papers: Minimal models with light sterile neutrinos
We determine the possible values of the effective Majorana neutrino mass $|< m > |= |\sum_j U_{ej}^2 m_j|$ in the different phenomenologically viable three and four-neutrino scenarios. The quantities $U_{\alpha j}$ ($\alpha =…
We explore the neutrino sector of the minimal left-right symmetric model, with the additional charge conjugation discrete symmetry, in the tuned regime where type-I and type-II seesaw mechanisms are equally responsible for the light…
In light of the recent solar and atmospheric neutrino data, we investigate the possibility of having an exactly degenerate spectrum for heavy right-handed Majorana neutrinos at the grand unification scale. The analysis is performed in the…
We have studied the constraints imposed by the results of neutrino oscillation experiments on the effective Majorana mass |<m>| that characterizes the contribution of Majorana neutrino masses to the matrix element of neutrinoless…
Sterile neutrinos as source of mass and flavor mixing of active neutrinos as well as genesis of dark matter (DM) and matter-antimatter asymmetry have gained special interest. Here we study the case of the Standard Model (SM) extended with…
A model of neutrino oscillations is presented that has only three degrees of freedom and is consistent with existing data. The model is a subset of the renormalizable sector of the Standard-Model Extension (SME), and it offers an…
The original Standard Model has massless neutrinos, but the observation of neutrino oscillations requires that neutrinos are massive. The simple extension of adding gauge singlet fermions to the particle spectrum allows normal Yukawa mass…
We study the link between neutrino oscillations and leptogenesis in the minimal framework assuming an SO(10) see-saw mechanism with 3 families. Dirac neutrino masses being fixed, the solar and atmospheric data then generically induce a…
We investigate neutrinoless double-beta decay ($0\nu\beta\beta$) in minimal extensions of the Standard Model of particle physics where gauge-singlet right-handed neutrinos give rise to Dirac and Majorana neutrino mass terms. We argue that…
The present experimental data on neutrino oscillations, neutrinoless double beta decay and tritium beta decay are collected together and possible mass ranges for Dirac and Majorana neutrinos are found. Four future experimental situations…
We present a minimal see-saw model based on an extension of the standard model (SM) which includes an additional U(1), with gauge charge $B - \frac{3}{2} (L_\mu + L_\tau)$. Requirement of anomaly cancellation implies the existence of two…
We consider the minimal seesaw model, the Standard Model extended by two right-handed neutrinos, for explaining the neutrino masses and mixing angles measured in oscillation experiments. When one of right-handed neutrinos is lighter than…
The first data released by the KamLAND collaboration have confirmed the strong evidence in favour of the LMA solution of the solar neutrino problem. Taking into account the ranges for the oscillation parameters allowed by the global…
We present a detailed discussion on neutrinoless double beta decay $(0\nu \beta \beta)$ within left-right symmetric models based on the gauge symmetry of type $SU(2)_L \times SU(2)_R \times U(1)_{B-L}$ as well as $SU(3)_L \times SU(3)_R…
We examine simple extension of the standard model with a pair of fermions, one singlet and a doublet, in a common thread linking the dark matter problem with the smallness of neutrino masses associated with several exciting features. In the…
The characteristic scale of neutral current, provided by an extension of Standard Model with a local group over the right-handed fermions, determines the smallness of neutrino masses of Dirac kind. The experimental observation of neutrino…
We examine the origin of neutrino masses and oscillations in the context of the six-dimensional standard model. The space-time symmetries of this model explain proton stability and forbid Majorana neutrino masses. The consistency of the…
We suggest that a singlet fermion $S$ exists beyond the standard see-saw structure. It mixes with light neutrinos via interactions with the right-handed neutrino components, so that $\n_e \to S$ conversion solves the solar neutrino problem.…
Weak interaction in nuclei represents a well-known venue for testing many of the fundamental symmetries of the Standard Model. In particular, neutrinoless double-beta decay offers the possibility to test Beyond Standard Model theories…
When three Majorana neutrinos describe the solar and atmospheric neutrino data via oscillations, a nonzero measurement of neutrinoless double beta ($0\nu\beta\beta$) decay can determine the sum of neutrino masses $\sum m_\nu$ if the solar…