相关论文: Can Neutrinos be Degenerate in Mass?
The solar and atmospheric data and possibly large value for the effective neutrino mass in neutrinoless double beta decay experiment together indicate that all the three neutrinos are nearly degenerate. A verifiable texture for the neutrino…
A parametrisation of the degenerate neutrino mass matrix obeying $\mu -\tau$ symmetry, is introduced for detailed numerical analysis. As a continuation of our earlier work on normal and inverted hierarchical models, the present…
We study models of neutrino masses which naturally give rise to an inverted mass hierarchy and bi-maximal mixing. The models are based on the see-saw mechanism with three right-handed neutrinos, which generates a single mass term of the…
If the upper limit on the effective (Majorana) neutrino mass from neutrinoless double beta decay experiments is confirmed to be much less than an electron-volt, then one way to reconcile it with the degenerate neutrino mass pattern…
If neutrinos are to play a relevant cosmological role, they must be essentially degenerate with a mass matrix of the bimaximal mixing type. We study this scenario in the MSSM framework, finding that if neutrino masses are produced by a…
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…
There are three observables related to neutrino mass, namely the kinematic mass in direct searches, the effective mass in neutrino-less double beta decay, and the sum of neutrino masses in cosmology. In the limit of exactly degenerate…
Considering a general mass matrix for quasi-degenerate neutrinos and treating the experimentally known oscillation parameters as inputs, we study the correlation between the degenerate mass scale $(m)$ and the mixing angle $\theta_{13}$. We…
In the context of the seesaw mechanism, it is natural that the large solar and atmospheric neutrino mixing angles originate separately from large 2 by 2 mixings in the neutrino and charged-lepton sectors, respectively, and large mixing in…
Degenerate neutrino masses are excluded by experiment. The experimentally measured mass squared differences together with the yet undetermined absolute neutrino mass scale allow for a quasi-degenerate mass spectrum. For the lightest…
The renormalization-group effects on the scenario with nearly degenerate mass and bi-maximal mixing of neutrinos are analyzed. As a consequence, we explicitly show in the SO(3) gauge model that the renormalization-group effects could modify…
We suggest mass matrices for neutrinos and charged leptons that can explain solar and atmospheric neutrino data. The resulting flavor mixing matrix $V_{\nu}$ has a property that $(V_{\nu})_{13}=0$, thus making $\nu_e \leftrightarrow…
We propose a type II upgrade of type I see-saw models leading to new classes of models where partially degenerate neutrinos are as natural as hierarchical ones. The additional type II contribution to the neutrino mass matrix, which…
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…
We examine the constraints on the MNS lepton mixing matrix =66rom the present and future experimental data of the neutrino oscillation, tritium beta decay, and neutrinoless double beta decay for Majorana neutrinos. We show that the small…
In models with two sources of neutrino masses, we look at the possibility of generating maximal/large mixing angles in the total mass matrix, where both the sources have only small mixing angles. We show that in the two generation case,…
The simplest unified extension of the MSSM with bi-linear R--Parity violation naturally predicts a hierarchical neutrino mass spectrum, in which one neutrino acquires mass by mixing with neutralinos, while the other two get mass…
We discuss neutrino masses in the framework of a minimal extension of the minimal supersymmetric standard model (MSSM) consisting of an additional single right-handed neutrino superfield $N$ with a heavy Majorana mass $M$, which induces a…
We consider phenomenologically allowed structures of the neutrino mass matrix in the case of three light neutrino species. Constraints from the solar, atmospheric and reactor neutrino experiments as well as those from the neutrinoless…
The mass matrix of three Majorana neutrinos of equal mass is not necessarily proportional to the identity matrix, but expressible in terms of two angles and one phase. We discuss how such a mass matrix may be stable or unstable against…