Octant Degeneracy, Quadrant of leptonic CPV phase at Long Baseline Neutrino Experiments and Baryogenesis

In a recent work by us, we have studied, how CP violation discovery potential can be improved at long baseline neutrino experiments (LBNE/DUNE), by combining with its ND (near detector) and reactor experiments. In this work, we discuss how this study can be further analysed to resolve entanglement of the quadrant of leptonic CPV phase and Octant of atmospheric mixing angle $\theta_{23}$, at LBNEs. The study is done for both NH (Normal hierarchy) and IH (Inverted hierarchy), HO (Higher Octant) and LO (Lower Octant). We show how baryogenesis can enhance the effect of resolving this entanglement, and how possible values of the leptonic CP-violating phase $\delta_{CP}$ can be predicted in this context. With respect to the latest global fit data of neutrino mixing angles, we predict the values of $\delta_{CP}$ for different cases. In this context we present favoured values of $\delta_{CP}$ ($\delta_{CP}$ range at $\geq$ 2$\sigma$ ) constrained by the latest updated BAU range and also confront our predictions of $\delta_{CP}$ with an up-to-date global analysis of neutrino oscillation data. We find that some region of the favoured $\delta_{CP}$ parameter space lies within the best fit values around $\delta_{CP} \simeq 1.3\pi-1.4 \pi$. A detailed analytic and numerical study of baryogenesis through leptogenesis is performed in this framework in a model independent way.Comment: 14 pages, 5 figures, 2 Tables, New Analysi

Compatibility of A4A_{4} Flavour Symmetric Minimal Extended Seesaw with (3+1)(3+1) Neutrino Data

Motivated by the recent resurrection of the evidence for an eV scale sterile neutrino from the MiniBooNE experiment, we revisit one of the most minimal seesaw model known as the minimal extended seesaw that gives rise to a $3+1$ light neutrino mass matrix. We consider the presence of $A_4$ flavour symmetry which plays a non-trivial role in generating the structure of the neutrino mass matrix. Considering a diagonal charged lepton mass matrix and generic vacuum alignments of $A_4$ triplet flavons, we classify the resulting mass matrices based on their textures. Keeping aside the disallowed texture zeros based on earlier studies of $3+1$ neutrino textures, we categorise the remaining ones based on texture zeros, $\mu-\tau$ symmetry in the $3\times3$ block and hybrid textures. After pointing out the origin of such $3+1$ neutrino textures to $A_4$ vacuum alignments, we use the latest $3+1$ neutrino oscillation data and numerically analyse the texture zeros and $\mu-\tau$ symmetric cases. We find that a few of them are allowed from each category predicting interesting correlations between neutrino parameters. We also find that all of these allowed cases prefer normal hierarchical pattern of light neutrino masses over inverted hierarchy.Comment: 46 pages, 8 figures, 21 table

Charged Lepton Flavor Violation μ→eγ\mu\rightarrow e\gamma in μ−τ\mu-\tau Symmetric SUSY SO(10) mSUGRA, NUHM, NUGM, and NUSM theories and LHC

Charged Lepton Flavor Violation (cLFV) processes like $\mu \rightarrow e \gamma$ are rare decay processes, that are another signature of physics beyond Standard Model (BSM). These processes have been studied in various models, that could explain neutrino oscillations and mixings. In this work, we present bounds on cLFV decay $\mu \rightarrow e \gamma$ in a $\mu$-$\tau$ symmetric SUSY SO(10) theory, using type I seesaw mechanism. The updated constraints on BR($\mu \rightarrow e \gamma$) from MEG experiment, recently measured value of Higgs mass at LHC and value of $\theta_{13}$ from reactor data have been used. We present our results in mSUGRA, NUHM, NUGM and NUSM models, and sensitivity to test these theories at next run of LHC is also discussed.Comment: 22 pages, 6 figures, 6 Table

A new viable mass region of Dark matter and Dirac neutrino mass generation in a scotogenic extension of SM

We propose a scotogenic extension of the Standard Model which can provide a scalar Dark Matter candidate in the new, theoretically previously unaddressed, intermediate region ($200\leq M_{DM}\leq 550$ GeV) and also generate light Dirac neutrino masses. In this framework, the standard model is extended by three gauge singlet fermions, two singlet scalar fields, and one additional scalar doublet, all of which are odd under $Z_{2} \times Z_{4}$ discrete symmetry. These additional symmetries prevent the singlet fermions from obtaining Majorana mass terms along with providing the stability to the dark matter candidate. It is known that in the case of the scalar singlet DM model, the only region which is not yet excluded is a narrow region close to the Higgs resonance $m_{S} \simeq\frac{m_{h}}{2}$ - others ruled out from different experimental and theoretical bounds. In the case of the Inert doublet model, the mass region ($\sim 60$-$80$ GeV) and the high mass region (heavier than $550$ GeV) are allowed. This motivates us to explore a parameter range in the intermediate-mass region $M_{W}\leq M_{DM}\leq 550$ GeV, which we do in a scotogenic extension of SM with a scalar doublet and scalar singlets. The dark matter in our model is a mixture of singlet and doublet scalars. We constrain the allowed parameter space of the model using Planck bound on present dark matter relic abundance, neutrino mass, and the latest bound on spin-independent DM-nucleon scattering cross-section from XENON1T experiment. Our model may provide a viable DM candidate in the new, previously unexplored mass range ($200\leq M_{DM}\leq 550$ GeV), if this new window for the DM candidate mass is detected in future experiments, along with explanation of Dirac mass of neutrinos, since so far there is no strong evidence in support of Majorana nature of neutrino mass.Comment: 16 pages, 7 figures, 1 tabl