Search

We construct an $S_4$ flavour symmetric minimal inverse seesaw model where the standard model is extended by adding two right-handed and two standard model gauge singlets neutrinos to explain the origin of tiny neutrino masses. The resulting model describes the lepton mass spectra and flavour mixing quite well for the case of the normal hierarchy of neutrino masses. The prediction of the model on the Dirac CP-violating phase is centered around $370.087^\circ$. Furthermore, using the allowed region for the model parameters, we have calculated the value of the effective Majorana neutrino mass, $\lvert\langle m_{ee}\rangle\rvert$, which characterizes neutrinoless double beta decay., 12 pages, 4 figures, 3 tables

Our analysis involves enhancing the $Δ(54)$ flavor symmetry model with Inverse Seesaw mechanism along with two SM Higgs through the incorporation of distinct flavons. Additionally, we introduce supplementary $Z_2\otimes Z_3 \otimes Z_4$ symmetries to eliminate any undesirable components within our investigation. The exact tri-bimaximal neutrino mixing pattern undergoes a deviation as a result of the incorporation of extra flavons, leading to the emergence of a non-zero reactor angle $θ_{13}$ that aligns with the latest experimental findings. It was found that for our model the atmospheric oscillation parameter occupies the lower octant for normal hierarchy case. We also examine the parameter space of the model for normal hierarchy to explore the Dirac CP ($δ_{CP}$), Jarlskog invariant parameter ($J$) and the Neutrinoless double-beta decay parameter ($m_{ββ}$) and found it in agreement with the neutrino latest data. Hence our model may be testable in the future neutrino experiments., 18 pages, 6 figures, 3 tables

We study a neutrino mass model with $A_4$ discrete flavor symmetry using a type-I seesaw mechanism. The inclusion of extra flavons in our model leads to the deviations from exact tribimaximal mixing pattern resulting in a nonzero $\theta_{13}$ consistent with the recent experimental results and a sum rule for light neutrino masses is also obtained. In this framework, a connection is established among the neutrino mixing angles: reactor mixing angle($\theta_{13}$), solar mixing angle($\theta_{12}$) and atmospheric mixing angle ($\theta_{23}$). This model also allows us a prediction of Dirac CP-phase and Jarlskog parameter $J$. The octant of the atmospheric mixing angle $\theta_{23}$ occupies the lower octant. Our model prefers normal hierarchy (NH) than inverted hierarchy (IH). We use the parameter space of our model of neutrino masses to study the neutrinoless double beta decay parameter $m_{ee}$. Keywords: Discrete flavor symmetry, Type-I seesaw mechanism, Tribimaximal mixing, Dirac CP-phase, Jarlskog parameter, Neutrinoless double beta decay, Comment: 15 pages, 3 Figures, 2 Tables. arXiv admin note: substantial text overlap with arXiv:2203.05536

We study the modification of the Altarelli-Feruglio $A_4$ flavor symmetry model by adding three singlet flavons $ξ'$, $ξ''$ and $ρ$ and the model is augmented with extra $Z_2\times Z_2^ \prime$ symmetry to prevent the unwanted terms in our study. The addition of these three flavons lead to two higher order corrections in the form of two perturbation parameters $ε$ and $ε^\prime$. These corrections yield the deviation from exact tri-bimaximal (TBM) neutrino mixing pattern by producing a non-zero $θ_{13}$ and other neutrino oscillation parameters which are consistent with the latest experimental data. In both the corrections, the neutrino masses are generated via Weinberg operator. The analysis of the perturbation parameters $ε$ and $ε^\prime$, shows that normal hierarchy (NH) and inverted hierarchy (IH) for $ε$ does not change much. However, as the values of $ε^\prime$ increases, $θ_{23}$ occupies the lower octant for NH case. We further investigate the neutrinoless double beta decay parmeter $m_{ββ}$ using the parameter space of the model for both normal and inverted hierarchies of neutrino masses., 19 pages, 6 figures, 3 tables

Till today lepton flavor violation has not been observed in processes involving charged leptons. Hence, a search for it is under hot pursuit both in theories and experiments. In our current work, we investigate the rates of rare decay processes such as $\tau \rightarrow \mu \gamma$ in SU(5) SUSY GUT and found that it satisfies the current bound and is one order below the projected sensitivity. This gives a corroborative argument for the influence of the large top-Yukawa coupling at the GUT scale ($\lambda_{tG}$) on flavor violating decay rates of leptons which are investigable at low energy electroweak scale $M_Z$. Secondly, we discuss the decay rates of $\mu \rightarrow e \gamma$ & $\tau \rightarrow \mu \gamma$ in MSSM with added right handed neutrino superfields. From this, we set bounds on $\tan \beta$ and further, we investigate the mass of $\tilde{\chi}^0 _1$, the LSP, using the rates of LFV decays. In the calculations, the latest updated data from LHC, neutrino oscillation experiments and constraints on branching ratios from the MEG experiment have been used., Comment: 12 pages (excluding references), 3 figures

Leptonic \textit{CP} violation search, neutrino mass hierarchy determination, and the precision measurement of oscillation parameters for a unitary test of the leptonic mixing matrix are among the major targets of the ongoing and future neutrino oscillation experiments. The work explores the physics reach for these targets by around 2027, when the third generation of the neutrino experiments starts operation, with a combined sensitivity of three experiments: T2K-II, NO$��$A extension, and JUNO. It is shown that a joint analysis of these three experiments can conclusively determine the neutrino mass hierarchy. Also, at certain values of \emph{true} \dcp, it provides closely around a $5��$ confidence level (C.L.) to exclude \textit{CP}-conserving values and more than a $50\%$ fractional region of \emph{true} $��_{\text{CP}}$ values can be explored with a statistic significance of at least a $3��$ C.L. Besides, the joint analysis can provide unprecedented precision measurements of the atmospheric neutrino oscillation parameters and a great offer to solve the $��_{23}$ octant degeneracy in the case of nonmaximal mixing., To match PRD version

We investigate the comparative studies of cosmological baryon asymmetry in different neutrino mass models with and without ��_13 by considering the three diagonal form of Dirac neutrino mass matrices, down-quark (4,2), up-quark (8,4) and charged lepton (6,2). The predictions of any models with ��_13 are consistent in all the three stages of leptogenesis calculations and the results are better than the predictions of any models without ��_13 which are consistent in a piecemeal manner with the observational data. For the best model, the normal hierarchy Type-IA for charged lepton (6,2) without ��_13, the predicted inflaton mass required to produce the observed baryon asymmetry is found to be 3.6x10 to the power 10 GeV corresponding to reheating temperature TR 4.5x10 to the power 6 GeV, while for the same model with ��_13, the inflaton mass is 2.24x10 to the power 11 GeV, TR 4.865x10 to the power 6 GeV and weak scale gravitino mass m(2 divided by 3) 100 GeV without causing the gravitino problem. These values apply to the recent discovery of Higgs boson of mass 125 GeV. The relic abundance of gravitino is proportional to the reheating temperature of the thermal bath. One can have the right order of relic dark matter abundance only if the reheating temperature is bounded to below 10 to the power 7 GeV., 18 pages, 3 Tables, no figure