相关论文: Neutrino texture dominated by Majorana lefthanded …
After an Introduction briefly describing the rise and fall of the three-zero texture of the Zee model, we discuss still-allowed two-zero textures for the Majorana three-neutrino mass matrix. Finally, a model with two right-handed neutrinos…
Two schemes of mixing of four massive neutrinos with two couples of close neutrino masses separated by a gap of the order of 1 eV can accommodate solar, atmospheric and LSND neutrino oscillation data. It is shown that long-baseline…
We give a general analysis of neutrino mixing in the seesaw mechanism with three flavors. Assuming that the Dirac and u-quark mass matrices are similar, we establish simple relations between the neutrino parameters and individual Majorana…
In the light of latest data of neutrino oscillation experiments, we carry out a systematic investigation on the texture structures of Majorana neutrino mass matrix $M_{\nu}$, which contain one vanishing neutrino mass and an equality between…
We discuss all possible schemes with four massive neutrinos inspired by the existing experimental indications in favour of neutrino mixing, namely the atmospheric, solar and LSND neutrino experiments. We argue that the scheme with a…
The recent T2K, MINOS and Double Chooz oscillation data hint a relatively large $\theta_{13}$, which can be accommodated by some general modification of the Tribimaximal/Bimaximal/Democratic mixing matrices. Using such matrices we analyze…
We propose a simple but suggestive seesaw model with two phenomenological conjectures: three heavy (right-handed) Majorana neutrinos are degenerate in mass in the symmetry limit and three light Majorana neutrinos have the tri-bimaximal…
We consider the seesaw mechanism of neutrino mass generation in the light of our present knowledge of the neutrino masses and mixing. We analyse the seesaw mechanism constrained by the following assumptions: (1) minimal seesaw with no Higgs…
We consider an extension of the Standard Model with three right-handed (RH) neutrinos and a Dirac pair of extra sterile neutrinos, odd under a discrete $Z_2$ symmetry, in order to have left-right symmetry in the neutrino content and obtain…
The theoretical basics of neutrino mass and mixing are reviewed. Dirac and Majorana masses are explained, and added together to produce the see-saw picture of the lightness of neutrinos. This picture predicts that neutrinos are Majorana…
We study a 3+1 active-sterile neutrino mixings model using an $A_4$ triplet right-handed neutrino $\nu_R$ and a singlet eV-scale sterile neutrino under $A_4\times Z_3 \times Z_2$ discrete symmetry. Four scalar flavons are considered to…
Neutrino masses arise via a seesaw mechanism and its mass hierarchy, with assumption that heavy Majorana neutrino mass matrix subject to $\mu-\tau$ symmetry and invariant under a cyclic permutation, are evaluated. Within this scenario, the…
We discuss a model in which three active and one sterile neutrino account for the solar, the atmospheric and the LSND neutrino anomalies. It is shown that if $N_\nu<4$ then these and other experiments and big bang nucleosynthesis constrain…
We reconsider the possibility that Majorana masses for the three known neutrinos are generated radiatively by the presence of a fourth generation and one right-handed neutrino with Yukawa couplings and a Majorana mass term. We find that the…
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,…
The basic characteristics used for the description of both Dirac and Majorana massive neutrinos are studied. Currently available experimental data for these characteristics are presented with an evidence of possible anomalies beyond the…
We study natural lepton mass matrices, obtained assuming the stability of physical flavour observables with respect to the variations of individual matrix elements. We identify all four possible stable neutrino textures from algebraic…
Two schemes of mixing of four massive neutrinos with two close neutrino masses separated by a gap of Delta m^2 about 1 eV^2 can accommodate solar, atmospheric and LSND neutrino oscillation data. It is shown that long-baseline nu(e)->nu(x)…
We discuss possibility of describing solar, atmospheric and LSND results with four neutrinos forming two quasi-degenerate pairs. The simplest versions of this 2+2 scheme with either $\nu_e$ or $\nu_\mu$ mixing exclusively with sterile…
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…