Related papers: Effective Neutrino Mass Operators: A Guide to Mode…
We discuss the possibilities of distinguishing among different mechanisms of neutrinoless double beta decay arising in the effective field theory framework. Following the review and detailed investigation of the particular ways of…
We use the scale of neutrino mass to derive model-independent naturalness constraints on possible contributions to muon decay Michel parameters from new physics above the electroweak symmetry-breaking scale. Focusing on Dirac neutrinos, we…
We discuss a 331 model with three scalar triplets and neutral fermion singlets. We show that in the 331 model with right-handed neutrinos, it is possible to obtain small active neutrino masses via the double and inverse seesaw mechanisms,…
We present an extension of the Casas-Ibarra parametrization that applies to all possible Majorana neutrino mass models. This framework allows us to systematically identify minimal models, defined as those with the smallest number of free…
If the present or upcoming searches for neutrinoless double beta decay give a positive result, the Majorana nature of massive neutrinos will be established. From the determination of the value of the effective Majorana mass parameter |<m>|,…
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…
Some years ago it was shown by Ma that in the context of the electroweak standard model there are, at the tree level, only three ways to generate small neutrino masses by the see-saw mechanism via one effective dimension-five operator. Here…
An attempt is made to generate the bimaximal mixings of the three species of neutrinos from the textures of the right-handed Majorana neutrino mass matrices. We extend our earlier work in this paper for the generation of the nearly…
We consider a Majorana neutrino mass matrix $\mathcal{M}_\nu$ with $(\mathcal{M}_\nu)_{\mu\mu} = (\mathcal{M}_\nu)_{\tau\tau} = 0$, in the basis where the charged-lepton mass matrix is diagonal. We show that this pattern for the lepton mass…
It is shown that, in the framework of the scheme with three-neutrino mixing and a mass hierarchy, the results of neutrino oscillation experiments imply an upper bound of about 10^{-2} eV for the effective Majorana mass in neutrinoless…
Virtual Majorana neutrinos are indispensable for neutrinoless double-beta (0$\nu\beta\beta$) decay. In this study, we demonstrate that the overlap of the virtual Majorana neutrino wavefunction, predominantly composed of a right-handed…
The observation of neutrino oscillations and hence non-zero neutrino masses provided a milestone in the search for physics beyond the Standard Model. But even though we now know that neutrinos are massive, the nature of neutrino masses,…
We analyze the structure of quark and lepton mass matrices under the hypothesis that they are determined from a minimum principle applied to a generic potential invariant under the $\left[SU(3)\right]^5\otimes \mathcal O(3)$ flavor…
We consider the running of the neutrino mass matrix in the Standard Model and the Minimal Supersymmetric Standard Model, extended by heavy singlet Majorana neutrinos. Unlike previous studies, we do not assume that all of the heavy mass…
In these lectures (at the 2007 Summer School in Akyaka, Mugla, Turkey), I discuss the various mechanisms for obtaining small Majorana neutrino masses, as well as specific models of varying complexity, in the context of the standard model…
We consider the seesaw model with two right-handed neutrinos $N_1$ and $N_2$ which masses are hierarchical, and investigate their contribution to the neutrinoless double beta ($0 \nu \beta \beta$) decay. Although the lepton number is broken…
We propose a new model with the Majorana neutrino masses generated at two-loop level, in which the lepton number violation (LNV) processes, such as neutrinoless double beta decays, are mainly induced by the dimension-7 LNV effective…
Considering the scheme with mixing of three neutrinos and a mass hierarchy that can accommodate the results of solar and atmospheric neutrino experiments, it is shown that the results of solar neutrino experiments imply a lower bound for…
In this proceeding we present predictions of the effective Majorana mass $|m_{\beta\beta}|$ in neutrinoless double-$\beta$ decay for the standard $3\nu$ mixing case and for the 3+1 neutrino mixing case indicated by the short-baseline…
Heavy Majorana neutrinos enter in many scenarios of physics beyond the Standard Model: in the original seesaw mechanism they provide a natural explanation for the small masses of the Standard Model neutrinos and in the simplest leptogenesis…