arXiv subjects
Publications and source records attributed to Sagar Tirtha Goswami.
A predictive neutrino mass matrix texture, sheltering unique correlations ($m_{12}=m_{13}\,\,\&\,\,m_{33}=2i\, m_{12}$), is proposed, addressing most of the timely neutrino phenomenology issues. The texture is realized in the framework of type-I + type-II seesaw in the light of the $A_4 \times Z_{10} \times Z_{7} \times Z_{3}$ group. The stability of the proposed texture is studied under renormalization group evolution.
A minimal and predictive neutrino mass matrix texture for Majorana neutrino is proposed. The texture favours the normal hierarchy of neutrino mass eigenvalues. It further predicts the octant of $θ_{23}$, constraints $δ$, gives bounds on neutrino mass eigenvalues and also gives ranges for the two Majorana phases.The texture is realised in the framework of a Type-I seesaw and a Weinberg like dimension 6 operator under an extended symmetry of $SU(2)_L \otimes U(1)_Y \otimes A_4 \otimes Z_{10} \otimes Z_7 \otimes Z_5 \otimes Z_3$. The texture can be realised with different sets of vacuum expectation values of the associated scalar fields, but not all such sets lead to a viable scalar sector. The model also constrains the allowed channels of charged lepton flavour violation and leads to a suppressed baryon asymmetry generation through conventional leptogenesis.
We propose a new, minimal Majorana neutrino mass matrix texture and study its predictions within a partial tri-bimaximal (TBM) mixing scheme, where $\sinθ_{12} = 1/\sqrt{3}$ and $\sinθ_{23} = 1/\sqrt{2}$, with $θ_{13}$ and $δ$ treated as free parameters. The texture forbids $θ_{13} = 0$ and does not correspond to a $μ-τ$ symmetric structure. As a notable feature, the texture predicts the equality of the Majorana phases. In addition, we find that the predictions show distinct behavior depending on the sign of a single real texture parameter. The texture is realized through a hybrid framework of one Type-I seesaw and two Type-II seesaw mechanisms under an extended symmetry group, $SU(2)_L \otimes U(1)_Y \otimes A_4 \otimes Z_{10} \otimes Z_{7}$ with properly chosen model parameters. The texture is seen to favor the normal hierarchy for neutrino masses.
A Dirac neutrino mass model is proposed, based on an extended group structure of $SU(2)_L \otimes U(1)_Y \otimes A_4 \otimes Z_3 \otimes Z_{10}$ with the Type-I seesaw mechanism. This work explores the impact of parametrization and permutation in the charged lepton diagonalizing matrix, driven by free parameters in the charged lepton sector, on the predictions of observable parameters. Some interesting consequences on the neutrino mass hierarchies, mixing angles and the Dirac CP phase are observed. The framework also finds application in the study of charged lepton flavour violation and dark matter.
Assuming that neutrinos are not Majorana fermions and the right handed Dirac neutrino does not exist, we propose a model in which the second and the third generations of the leptons are composites, while the first generation is fundamental. The composite states are formed by the fundamental leptons and two new fundamental hidden scalar particles. In addition, there exist two hidden forces besides the SM interactions. The gauge symmetry $SU(2)_L\otimes U(1)_{Y}\otimes U(1)_h\otimes SU(2)_h$ of the electroweak and the hidden forces breaks down to $U(1)_{Y}\otimes U(1)_h$ after the spontaneous symmetry breaking (SSB). We explain the neutrino masses in terms of the binding dynamics of a hidden force. The phenomenon of neutrino oscillation can also be explained by our model in a dynamical framework of the hidden forces