Predictive S4 flavon model with TM1 mixing and baryogenesis through leptogenesis

Abstract

We use S 4 discrete group to construct a neutrino flavour model which leads to T M 1 mixing and is consistent with the neutrino oscillation data. Using the model's constrained parameter space, we predict the values of Dirac CP phase and the light neutrino mass as −1 < sin δ < −0.9 and 1.7 < m 1 (meV) < 5.5 respectively. We thoroughly examine the usefulness of this model in explaining the observed baryon asymmetry of the Universe. Near-maximal breaking of CP symmetry (arising due to the TM 1 constraint) helps us in generating adequate baryon asymmetry through leptogenesis. We study the evolution of the asymmetry (generated due to the decay of the heavy Majorana neutrinos) starting from the primordial Universe in two different ways (i)explicitly solving network of Boltzmann equations, (ii) using approximate analytic solution and we have shown the extent of their equivalence. Nearly accurate analytical fits are used thereafter to evaluate baryon asymmetry for the whole parameter space allowed by 3σ global fit of oscillation data and to impose a constraint on the yet unbounded mass scale parameter of Dirac neutrino mass matrix. Furthermore, significant contribution of N 2 decay in the context of flavoured leptogenesis is also estimated.

Effect of Sterile Neutrino on Low-Energy Processes in Minimal Extended Seesaw With Δ(96) Symmetry and TM1 Mixing

“…Trimaximal (TM 1 ) mixing is a mixing ansatz that preserves the first column of tri-bimaximal mixing U TBM and mixes its second and third columns. It is a perturbation to TBM mixing, and we can write the mixing matrix as [37,38]…”

Resonant leptogenesis and TM$$_1$$ mixing in minimal type-I seesaw model with S$$_4$$ symmetry

“…tion on the mixing angles θ 13 , θ 23 and the Dirac phase, δ C P . Over the years, many discrete symmetry-based studies have been done that gives rise to TM 1 mixing [25][26][27][28][29][30][31]. Herein, we propose a model constructed using S 4 discrete symmetry within the framework of the minimal seesaw model.…”

Resonant leptogenesis and TM$_1$ mixing in minimal Type-I seesaw model with S$_4$ symmetry

“…TM 1 mixing has proved to be compatible with the global data on neutrino oscillations, in a sense that it includes non-zero θ 13 and agrees very well with the experiments on its prediction on the 2 mixing angles θ 13 , θ 23 and the Dirac phase, δ CP . Over the years, many discrete symmetry-based studies have been done that gives rise to TM 1 mixing [24][25][26][27][28][29]. Herein, we propose a model based constructed using S 4 discrete symmetry within the framework of the minimal seesaw model.…”