Related papers: The Seesaw Evaded Modular Dirac Framework
We present an $A4$-based model where neutrino masses arise from a combination of see-saw mechanisms. The model is motivated by several small mixing and mass parameters indicated by the data. These are $\theta_{13}$, the solar mass…
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…
We propose a model for lepton mass matrices based on the seesaw mechanism, a complex scalar gauge singlet and a horizontal symmetry $S_3 \times \mathbbm{Z}_2$. In a suitable weak basis, the charged-lepton mass matrix and the neutrino Dirac…
We systematically analyze the Dirac and the Majorana mass matrices in seesaw models with two heavy right-handed neutrinos. We perform thorough classification of the vanishing matrix elements which are compatible with the results from the…
We present a unified axion model framework that simultaneously addresses the origin of neutrino masses, leptonic flavor structure, the strong CP problem, and dark matter. The model is based on a global $U(1)_{\rm PQ}$ symmetry combined with…
Many studies have been made on extensions of the standard model with $B-L$ gauge symmetry. The addition of three singlet (right-handed) neutrinos renders it anomaly-free. It has always been assumed that the spontaneous breaking of $B-L$ is…
We investigate the see-saw mechanism for generally non-fine-tuned $n \times n$ mass matrices involving both Dirac and Majorana neutrinos. We specifically show that the number of naturally light neutrinos cannot exceed half of the dimension…
The Standard Model (SM) with one right-handed neutrino per generation is revisited with presymmetry being the global $U(1)_{B-L}$ symmetry of an electroweak theory of leptons and quarks with initially postulated symmetric fractional…
We construct a neutrino mass model based on the flavour symmetry group $A_4\times C_4 \times C_6 \times C_2$ which accommodates a light sterile neutrino in the minimal extended seesaw (MES) scheme. Besides the flavour symmetry, we introduce…
We discuss neutrino mass and mixing in the framework of the classic seesaw mechanism, involving right-handed neutrinos with large Majorana masses, which provides an appealing way to understand the smallness of neutrino masses. However, with…
We propose a $U(1)_L$ model with $A_4$ symmetry in light of the linear seesaw for majorana neutrino that capable of generating the current lepton and quark mass and mixing patterns. The smallness of Majorana neutrino mass is reproduced…
In the presence of a finite modular flavour symmetry, fermion mass hierarchies may be generated by a slight deviation of the modulus from a symmetric point. We point out that this small parameter governing charged-lepton mass hierarchies…
We present a model of neutrino masses combining the seesaw mechanism and strong Dirac mass hierarchy and at the same time exhibiting a significantly reduced hierarchy at the level of active neutrino masses. The heavy Majorana masses are…
We propose two new simple lepton flavor models in the framework of the $S_4$ flavor symmetry. The neutrino mass matrices, which are given by two complex parameters, lead to the inverted mass hierarchy. The charged lepton mass matrix has the…
We present a version of the Type II Seesaw mechanism for parametrically small Dirac neutrino masses. Our model starts from an $\text{SU}(2)_\text{L} \otimes \text{SU}(2)'\otimes \text{U}(1)_\text{X}$ gauge extension of the Standard Model…
In this paper, we construct a model with the help of modular symmetry in the framework of minimal inverse seesaw [ISS(2,3)]. We have used $\Gamma(3)$ modular group which is isomorphic to non-Abelian discrete symmetry group $A_4$. In this…
A non-supersymmetric inverse seesaw model of neutrino mass based on the $A^{\prime}_5$ modular symmetry is presented. This framework provides a combined explanation for neutrino masses, mixing, and the cosmic baryon asymmetry through…
In this paper, we investigate lepton mass spectra, flavor mixing and CP violation with a modular $S^{}_4$ symmetry under the assumption that neutrinos are Dirac fermions. We find that the Majorana mass term can be forbidden by adjusting the…
We point out that the minimal seesaw model can provide a natural framework to accommodate tiny neutrino masses, while its experimental testability and notable predictiveness are still maintained. This possibility is based on the observation…
We present minimalist constructions for lepton masses and mixing based on flavour symmetry under the modular group $\Gamma_N$ of lowest level $N=2$. As opposed to the only existing model of $\Gamma_2\cong S_3$ formulated in a SUSY…