Type III seesaw under $A_4$ modular symmetry with leptogenesis and muon $g-2$

Abstract

We make an attempt to study neutrino phenomenology in the framework of type-III seesaw by considering A 4 modular symmetry in the super-symmetric context. In addition, we have included local U (1) B−L symmetry which eventually helps us to avoid certain unwanted terms in the superpotential. Hitherto, the seesaw being type-III, it involves the fermion triplet superfields Σ, along with which, we have included a singlet weighton field (ρ). In here, modular symmetry plays a crucial role by avoiding the usage of excess flavon (weighton) fields. Also, the Yukawa couplings acquire modular forms which are expressed in terms of Dedekind eta function η(τ ). However, for numerical analysis we use q expansion expressions of these couplings. Therefore, the model discussed here is triumphant enough to accommodate the observed neutrino oscillation data. Additionally, it also successfully explains leptogenesis and sheds some light on the current results of muon (g − 2).

Neutrino Phenomenology and Leptogenesis in Type-III Seesaw under A_4 Modular Symmetry

“…A symmetry-based approach is likely to be the most effective. We explore A 4 modular symmetry in type-III seesaw mechanism with U(1) B−L gauged symmetry [2]. The advantage, of working in modular symmetry is that scalar fields are not needed anymore and the symmetry breaking is performed by the VeV of complex modulus field 𝜏 [1].…”

“…Σ is the mass parameter and the Yukawa couplings are function of complex modulus 𝜏 [2]. The neutrino mass takes the following form in type-III seesaw mechanism,…”