Related papers: Neutrino Masses and Mixings from String Theory Ins…
A new mechanism is proposed to explain neutrino masses and their mixing via SU(1,1) horizontal symmetry breaking. Based on this mechanism smallness of neutrino masses is naturally realized and inverted hierarchical spectrum with large…
A large hierarchy of the Dirac masses can result in a small hierarchy for the low energy masses of the active neutrinos. This can happen even if the Majorana masses of right-handed neutrinos are all equal. A realistic description of the…
Neutrino mass patterns and mixing have been studied in the context of next-to-minimal supersymmetric standard model (NMSSM) with three gauge singlet neutrino superfields. We consider the case with the assumption of R-parity conservation.…
Recently, many authors showed that if the solar and atmospheric neutrino data are both described by maximal mixing vacuum oscillations at the relevant mass scale, then there exists a unique bi-maximal lepton mixing matrix for three neutrino…
In view of the recent neutrino oscillation data pointing to a non-vanishing value for the smallest mixing angle ($\theta_z$), we derive and find explicit realizations of the $(Z_2)^3$ flavor symmetry which characterizes, for the neutrino…
We investigate the generation of small neutrino masses in a clockwork framework which includes Dirac mass terms as well as Majorana mass terms for the new fermions. We derive analytic formulas for the masses of the new particles and for…
We survey some of the recent promising developments in the search for the theory behind neutrino mass and tri-bimaximal mixing, and indeed all fermion masses and mixing. We focus in particular on models with discrete family symmetry and…
Recent developments in string theory have led to "realistic" string compactifications which lead to moduli stabilization while generating a hierarchy between the Electroweak and Planck scales at the same time. However, this seems to suggest…
Flavour physics is a priceless window on physics beyond the Standard Model. In particular, flavour violation in the lepton sector looks very promising, as high precision measurements are prospected in future experiments investigating on…
The flavour problem and the viability of texture zeros of the Majorana mass matrix in the 3+1 active-sterile neutrino mixing scenario are investigated in this work using a novel bottom-up technique where we leverage the pertinent concepts…
The unique dimension-$5$ effective operator, $LLHH$, known as the Weinberg operator, generates tiny Majorana masses for neutrinos after electroweak spontaneous symmetry breaking. If there are new scalar multiplets that take vacuum…
In this paper we discuss a new way to derive neutrino mixing patterns, which originates from the idea proposed in a recent article by Hernandez and Smirnov. Its applications to various cases are discussed. We first present the complete set…
We study effects of D-brane instantons wrapping rigid cycles on Z2*Z2' toroidal orbifold. We compute Majorana masses induced by rigid D-brane instantons and realize bimaximal mixing matrices in certain models. We can also derive more…
The four light neutrino scenario, which explains the atmosphere, solar and LSND neutrino experiments, is studied in the framework of the seesaw mechanism. By taking both the Dirac and Majorana mass matrix of neutrinos to be singular, the…
We present the general form of the unitary matrices keeping invariant the Majorana neutrino mass matrix of specific texture suitable for explaining oscillation data. In the case of the Tri-bimaximal pattern with two degenerate masses we…
A simple model of the neutrino mixing is considered, which contains only one right-handed neutrino field, coupled via the mass term to the three usual left-handed fields. This is a simplest model that allows for three-flavour neutrino…
Four different neutrino mass sum-rules have been analyzed: these frequently arise in flavor symmetry models based on the groups A_4, S_4 or T', which are often constructed to generate tri-bimaximal mixing. In general, neutrino mass can be…
New effects related to refraction of neutrinos in different media are reviewed and implication of the effects to neutrino mass and mixing are discussed. Patterns of neutrino masses and mixing implied by existing hints/bounds are described.…
A beautiful understanding of the smallness of the neutrino masses may be obtained via the seesaw mechanism, whereby one takes advantage of the key qualitative distinction between the neutrinos and the other fermions: right-handed neutrinos…
Assuming that a horizontal abelian (gauge) symmetry is at the origin of texture zeros in the fermion mass matrices we show how realistic mass patterns can be generated stepwise with a small number of effective operators from GUT's and…