Dark matter and low scale leptogenesis in a flavor symmetric neutrino two Higgs doublet model($\nu$2HDM)

TL;DR

This paper explores a flavor symmetric two Higgs doublet model that simultaneously addresses dark matter, low scale leptogenesis, and neutrinoless double beta decay, providing a comprehensive framework consistent with current experimental constraints.

Contribution

It introduces a novel extension of the $ u$2HDM incorporating flavor symmetry and dark sector components, achieving consistent explanations for neutrino masses, dark matter, and leptogenesis.

Findings

Dark matter relic abundance and free streaming length are consistent with keV-scale fermions.

Effective neutrino mass in neutrinoless double beta decay is within experimental limits.

Low scale leptogenesis is successfully realized within the model.

Abstract

We have studied dark matter (DM) phenomenology, neutrinoless double beta decay (NDBD) and realized low scale leptogenesis in an extension of Standard Model(SM) with three neutral fermions, a scalar doublet and a dark sector incorporating a singlet scalar and a Dirac singlet fermion. A generic model based on $A_4\times Z_4$ flavor symmetry including five flavons is used to explain both normal and inverted hierarchy mass patterns of neutrino and also to accommodate the dark matter mass. In this extension of the $\nu$2HDM, the effective neutrino mass observed in $0\nu\beta\beta$ is well within the experimental limit provided by KamLAND-ZEN. In order to validate DM within this model, we have checked relic abundance and free streaming length of the dark sector component, i.e. a Dirac singlet fermion constraining its mass in keV range. More importantly we have also realised low scale leptogenesis simultaneously within this framework and also the Dirac CP phase gets constrained with the results. Bound from LFV is also incorporated in order to constrain the Yukawa couplings. More importantly, we have analyzed the dependence of various phenomenology with decay parameter for different choice of arbitrary complex angles.