Related papers: Neutrino Masses and Mixings from String Theory Ins…
We present a scenario of neutrino masses and mixing angles. Each generation includes a sterile right handed neutrino in addition to the usual left handed one. We assume a hierarchy in their Dirac masses similar to, but much larger than the…
We show that when sterile Majorana neutrino masses are generated non-perturbatively through instantonic interactions in certain classes of string compactifications (e.g. Type IIA orientifold models with intersecting D-branes), then the…
One can describe cosmological relic neutrinos by adding Lagrange multipliers to the Standard Model Lagrangian for them. The two possible Lagrange multipliers are a chemical potential, which fixes the mean neutrino/anti-neutrino asymmetry,…
The Majorana neutrino mass matrix combines information from the neutrino masses and the leptonic mixing in the flavor basis. Its invariance under some transformation matrices indicates the existence of certain residual symmetry. We offer an…
We propose a neutrino model based on a $\Delta(54)$ flavor symmetry suitable for explaining the current neutrino oscillation data. Neutrino masses arise from the type II seesaw mechanism where the $\Delta(54)$ field assignments has led to a…
We show that in theories that reduce, at the Fermi scale, to an extension of the standard model with two doublets, there can be additional dimension five operators giving rise to neutrino masses. In particular there exists a singlet…
This essay is intended to provide a brief description of the peculiar properties of neutrinos within and beyond the standard theory of weak interactions. The focus is on the flavor oscillations of massive neutrinos, from which one has…
We examine in detail the neutrino masses and mixing patterns in an extension of the minimal supersymmetric standard model with three gauge-singlet neutrinos and R-parity violation. The Majorana masses for the gauge-singlet neutrinos as well…
In spite of enormous experimental progress in determination of the neutrino parameters, theory of neutrino mass and mixing is still on the cross-roads. Guidelines could be (i) the connection between zero neutrino charges (and therefore a…
The implications of a large value of the effective Majorana neutrino mass for a class of two texture zero neutrino mass matrices have been studied in the flavor basis. It is found that these textures predict near maximal atmospheric…
A form of mixing matrix for three active and three sterile, conventional Majorana neutrinos is proposed. Its Majorana lefthanded part arises from the popular bimaximal mixing matrix for three active neutrinos that works satisfactorily in…
We discuss what kinds of combinations of Yukawa interactions can generate the Majorana neutrino mass matrix. We concentrate on the flavor structure of the neutrino mass matrix because it does not depend on details of the models except for…
We look for predictive flavour patterns of the effective Majorana neutrino mass matrix that are compatible with current neutrino oscillation data. Our search is based on the assumption that the neutrino mass matrix contains equal elements…
We discuss a new mechanism in which non-perturbative quantum gravity effects directly generate a Majorana mass for the neutron. In particular, in string theory, exotic instantons can generate an effective six quark operator by calculable…
The possible mechanisms of generation of the neutrino of small masses and sterile neutrino are considered. In the supposition of stability of tracks of a left-right symmetry concerning masses of constituent quarks, the angles of mixing of…
This work proposes two models of neutrino masses that predict non-zero $\theta_{13}$ under the non-Abelian discrete flavor symmetry $\mathbb{S}_3\otimes\mathbb{Z}_2$. We advocate that the size of $\theta_{13}$ is understood as a group…
We propose a novel theoretical understanding of neutrino masses and mixings, which is attributed to the intrinsic vector-like feature of the regularized Standard Model at short distances. We try to explain the smallness of Dirac neutrino…
We discuss the profile of neutrino masses and mixings in models with large extra dimensions when right handed neutrinos are present in the branes along with the usual standard model particles. In these models, string scale must be bigger…
We propose a next-to-minimal supersymmetric Standard Model (NMSSM) extended by an $\mathbb{A}_{4}\times \boldsymbol{Z}_{3}$ flavor symmetry and three right-handed neutrinos providing a detailed study of the neutrino sector and a solution to…
We investigate the interplay between the string scale and phenomenological scales in orientifold compactifications. Specifically, we discuss in generality the tension that often arises in accounting for neutrino masses, Yukawa couplings,…