# Double type-II seesaw accompanied by Dirac fermionic dark matter

## TL;DR

This paper proposes a model combining a low-scale type-II seesaw for neutrino masses with a $U(1)_{B-L}$ gauge symmetry, which also naturally includes a stable Dirac fermionic dark matter candidate and explains baryon asymmetry.

## Contribution

It introduces a novel framework linking neutrino mass generation, baryon asymmetry, and dark matter within a unified $U(1)_{B-L}$ extended seesaw model.

## Key findings

- Small triplet-doublet coupling can generate neutrino masses at TeV scale.
- The model simultaneously explains baryon asymmetry and dark matter stability.
- Predictions include potential signals for new gauge bosons and fermions at colliders.

## Abstract

In the type-II seesaw mechanism, the neutrino mass generation could be tested experimentally if the Higgs triplet is at the TeV scale and has a small cubic coupling to the standard model Higgs doublet. We show such small triplet-doublet coupling and the cosmic baryon asymmetry can be simultaneously induced by an additional seesaw mechanism involving a $U(1)_{B-L}$ gauge symmetry. Meanwhile, three neutral fermions for cancelling the gauge anomalies can form a stable Dirac fermionic dark matter besides an acceptably massless fermion.