Active and sterile neutrino phenomenology with A4 based minimal extended seesaw

Abstract

We study a model of neutrino within the framework of minimal extended seesaw (MES), which plays an important role in active and sterile neutrino phenomenology in (3+1) scheme. The A 4 flavor symmetry is augmented by additional Z 4 ×Z 3 symmetry to constraint the Yukawa Lagrangian of the model. We use non-trivial Dirac mass matrix, with broken µ − τ symmetry, as the origin of leptonic mixing. Interestingly, such structure of mixing naturally leads to the non-zero reactor mixing angle θ 13 . Non-degenerate mass structure for right-handed neutrino M R is considered so that we can further extend our study to Leptogenesis. We have also considered three different cases for sterile neutrino mass, M S to check the viability of this model, within the allowed 3σ bound in this MES framework.

Phenomenology of keV scale sterile neutrino dark matter with S4 flavor symmetry

“…These additional states must relate to right-handed neutrinos (RHN) for which bare mass terms are allowed by all symmetries i.e. they should not be present in SU (2) L × U (1) Y interactions, hence are sterile [24]. Sterile neutrino as its name indicates is stable and it has only gravitational interactions.…”

Phenomenological study of neutrino mass, dark matter and baryogenesis within the framework of minimal extended seesaw

“…In the fermion sector, we have chosen the MES framework, where, along with the active neutrino mass generation, the validity of baryogenesis is checked in the presence of a heavy flavor of sterile neutrino. Sterile phenomenology with the active neutrinos has already been discussed in JHEP03(2020)018 our previous work [37]. Within the scalar sector, we consider two additional Higgs doublets along with the SM Higgs doublet, where one additional Higgs doublet acquires VEV.…”

“…It is to be noted that the detailed study of the scalar potential and the interaction among the heavy scalar fields (ϕ, ζ, ξ, etc.) are worked out in [37], and the light scalar fields remains decoupled from these heavy scalar fields. These heavy scalar fields need to explain neutrino mass and mixing which we are going to discuss in the next subsection.…”

“…Along with this, the generation of non-zero reactor mixing angle (θ 13 ) and simultaneously carried out multi Higgs doublet framework where one of the lightest odd particles behaves as DM candidate. This work is an extension of our previous work on active-sterile phenomenology [37]. Hence, we do not carry out the sterile neutrino part in this work.…”

“…We also modify the Lagrangian for the M D matrix by introducing a new triplet flavon ϕ with VEV alignment as ϕ ∼ (2v m , −v m , −v m ), which affects only the Dirac neutrino mass matrix and give desirable active-sterile mixing in IH [33,37]. The invariant Yukawa Lagrangian for the M D matrix in IH mode will be,…”