Related papers: "Hidden" O(2) and SO(2) Symmetry in Lepton Mixing
Assuming a Zee-like matrix for the right-handed neutrino Majorana masses in the see-saw mechanism, one gets maximal mixing for vacuum solar oscillations, a very small value for $U_{e3}$ and an approximate degeneracy for the two lower…
We analyse a flavour model for a lepton sector which is based on type I seesaw mechanism, a Z_2 symmetry for lepton flavours, a mu-tau interchange symmetry and a CP symmetry. This model fits well the data of neutrino mass squared…
We show that both small mixing in the quark sector and large mixing in the lepton sector can be obtained from a simple assumption of universality of Yukawa couplings and the right-handed neutrino Majorana mass matrix in leading order. We…
We suggest a low-scale model based on $A_4\times Z_4 \times Z_2$ symmetry and a global lepton number $U(1)_L$ symmetry capable of generating the current neutrino data. The neutrino mass smallness is reproduced by the linear seesaw…
We propose a model based on the gauge group $SU(3)_{C}\otimes SU(3)_{L}\otimes U(1)_{X}$ with an extra $S_{3}$ flavor symmetry, which accounts for the lepton masses and mixing. The small active neutrino masses are generated via a double…
New models have recently been proposed in which a second Higgs doublet couples only to the lepton doublets and right-handed neutrinos, yielding Dirac neutrino masses. The vacuum value of this second "nu-Higgs" doublet is made very small by…
Assuming the same form of all mass matrices as motivated by quark-lepton symmetry, we discuss conditions under which bi-large mixing in the lepton sector can be obtained with a minimal amount of fine tuning requirements for possible models.…
We have discussed the quark-lepton mass matrices with the U(1) flavor symmetry in SU(5), which lead to the large mixing angle MSW solution of solar neutrinos. The solar neutrino solution depends on the next-leading terms in the neutrino…
We perform a systematic analysis of the PMNS matrices which arise when one assigns the three generations of leptons to the $2\oplus 1$ representation of a horizontal $SU_H(2)$ symmetry. This idea has been previously explored by Kuchimanchi…
We consider a minimal formulation of SO(10) Grand Unified Theory wherein all the fermion masses arise from Yukawa couplings involving one 126 and one 10 of Higgs multiplets. It has recently been recognized that such theories can explain,…
A simple model to accomodate light sterile neutrinos naturally with large mixing with the usual neutrinos has been proposed. The standard model gauge group is extended to include an $SU(2)_S$ gauge symmetry. Heavy triplet higgs scalars give…
We study the lepton sector in the model based on the local gauge group $SU(3)_c\otimes SU(3)_L\otimes U(1)_X$ which do not contain particles with exotic electric charges. The seesaw mechanism and discrete $A_4$ symmetry are introduced into…
In this talk we discuss the implications of the Minimal Supersymmetric Standard Model augmented by a single U(1) anomalous family symmetry for neutrino masses and mixing angles. The left-handed neutrino states are provided with Majorana…
We perform a detailed study of lepton mixing patterns arising from a scenario with three Majorana neutrinos in which a discrete flavor group Gf=Delta (3 n^2) or Gf=Delta(6 n^2) and a CP symmetry are broken to residual symmetries Ge=Z3 and…
We produce five flavour models for the lepton sector. All five models fit perfectly well---at the one-sigma level---the existing data on the neutrino mass-squared differences and on the lepton mixing angles. The models are based on the…
We show that maximal atmospheric and large solar neutrino mixing can be implemented in SU(5) gauge theories, by making use of the $U(1)_F$ symmetry associated with a suitably defined family number $F$, together with a $\mathbbm{Z}_2$…
We propose a model, in the framework of 5D with warped geometry, in which small neutrino Majorana masses are generated by tree level coupling of lepton doublets to a SU(2)_{L}-triplet scalar field, which is coupled to a bulk SM-singlet. The…
The problem of neutrino masses and mixing angles is analysed in a class of supersymmetric grand unified models, with SO(10) gauge symmetry and global U(2) flavour symmetry. Adopting the seesaw mechanism for the generation of the neutrino…
We consider trimaximal lepton mixing, defined by |U_{alpha 2}|^2 = 1/3 for all alpha = e, mu, tau. This corresponds to a two-parameter lepton mixing matrix U. We present a model for the lepton sector in which trimaximal mixing is enforced…
We examine the neutrino mass matrix in the version of Zee model where both Higgs doublets couple to the leptons. We show that in this case one can accommodate the large mixing angle (LMA) MSW solution of the solar neutrino problem, while…