Related papers: Tripartite Neutrino Mass Matrix
The compelling experimental evidences for oscillations of solar, reactor, atmospheric and accelerator neutrinos imply the existence of 3-neutrino mixing in the weak charged lepton current. The current data on the 3-neutrino mixing…
In the flavor basis where the mass eigenstates of three charged leptons are identified with their flavor eigenstates, one may diagonalize a 3 X 3 Majorana neutrino mass matrix M_nu by means of the standard parametrization of the 3 X 3…
We extend the Standard Model by adding a second Higgs doublet and a right-handed neutrino singlet with a heavy Majorana mass term. In this model, there are one heavy and three light Majorana neutrinos with a mass hierarchy m_3 >> m_2 >> m_1…
General Majorana neutrino mass matrix is complex symmetric and for three generations of neutrinos it contains 12 real parameters. We diagonalize this general neutrino mass matrix and express the three neutrino masses, three mixing angles,…
The three active light neutrinos are used to explain the neutrino oscillations. The inherently bi-large mixing neutrino mass matrix and the Fritzsch type, bi-small mixing charged lepton mass matrix are assumed. By requiring the maximal…
We motivate the simplest ansatz for the neutrino mass matrix consistent with the data from neutrino oscillation experiments, and admitting CP violation. It has only two free parameters: an arbitrary mass-scale and a small dimensionless…
We construct a mass matrix for the four neutrino flavors, three active and one sterile, needed to fit oscillations in all three neutrino experiments: atmospheric, solar, and LSND, simultaneously. It organizes the neutrinos into two doublets…
Under the assumption that the neutrinos are Majorana particles we study how the lepton mass matrices can be transformed into the simple form which has the same physical quantities by removing redundant parameters. We propose the exact…
An explicit mass formula is proposed for three active neutrinos and their heavy sterile (righthanded) counterparts in the framework of seesaw mechanism. The formula correlates reasonably the experimental estimates for the solar $\Delta…
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…
As an alternative for popular see-saw mechanism, the option of three pseudo% -Dirac neutrinos is discussed, where ${1/2}(m^{(L)} + m^{(R)}) \ll m^{(D)}$ for their Majorana and Dirac masses. The actual neutrino mass matrix is assumed in the…
we explore the consequences of assuming a simple 3-parameter form, first without T-violation, for the neutrino mass matrix M in the basis $\nu_e, \nu_\mu, \nu_\tau$ with a new symmetry. This matrix determines the three neutrino masses m_1,…
Consider the most general $3 \times 3$ Majorana neutrino mass matrix $\cal M$. Motivated by present neutrino-oscillation data, much theoretical effort is directed at reducing it to a specific texture in terms of a small number of…
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…
An approximate Z_3 family symmetry is proposed for leptons which results in a neutrino mass matrix with sin^2 2 theta_atm = 1 and tan^2 theta_sol = 0.5, but the latter value could easily be smaller. A generic requirement of this approach is…
In a wide class of unified models there is an additional (and possibly dominant) term in the neutrino mass formula that under the simplest assumption takes the form M_{\nu} = (M_N + M_N^T)u/M_G, where M_N is the neutrino Dirac mass matrix,…
In solar neutrino oscillations, if $\nu_e$ has a significant third massive component, the allowed parameter space in $\Delta m^2$ and $\sin^2 2 \theta$ for the first two components is shown to be greatly increased. This third component may…
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 simplify and extend our previous model for the masses and mixing matrix of three Majorana neutrinos based on permutation symmetry $S_3$ and the perturbations which violate this symmetry. The perturbations are arranged such that we get…
A universal seesaw mass matrix model, which gives successful description of quark mass matrix in terms of lepton masses, yields three "sterile" neutrinos \nu^s_{i}, which compose pseudo-Dirac neutrinos \nu_{i\pm}^{ps}\simeq (\nu_{i} \pm…