Dirac Scoto Inverse-Seesaw from $A_4$ Flavor Symmetry

TL;DR

This paper introduces a novel Dirac scotogenic inverse-seesaw model linking dark matter stability to $A_4$ flavor symmetry breaking, explaining neutrino masses, mixing, and dark matter properties within a unified framework.

Contribution

It proposes a new radiative neutrino mass model with $A_4$ flavor symmetry breaking that naturally stabilizes dark matter and explains neutrino oscillation data.

Findings

Successfully explains neutrino mass differences and mixing angles.

Identifies viable dark matter mass regions for scalar and fermionic candidates.

Shows compatibility with current experimental constraints on lepton flavor violation.

Abstract

We present a Dirac scotogenic-like one loop radiative model where the stability of dark matter is intricately linked to the breaking of $A_4$ flavor symmetry. This breaking induces a $Z_2$ dark symmetry, stabilizing the dark matter candidate. The breaking of $A_4 \to Z_2$ leads to cutting the loop and facilitating a "scoto inverse-seesaw" mass mechanism responsible for neutrino mass generation. This elucidates the explicit explanation of two mass-squared differences, $\Delta m^2_{\rm{atm}}$ and $\Delta m^2_{\rm{sol}}$ observed in neutrino oscillations. Our model accounts for normal and inverted ordering of neutrino masses, revealing sharp correlations between $\sum m_i$ and $\langle m_{\beta} \rangle$. It also shows strong compatibility with current data in the $\delta_{CP}$-$\theta_{23}$ plane. Moreover, stringent constraints on scalar masses narrow down the viable dark matter mass regions, accommodating $SU(2)_L$ singlet and doublet scalar dark matter as well as fermionic dark matter. Additionally, our model presents a viable avenue for addressing lepton flavor violating decays while remaining consistent with current experimental constraints.