Scotogenic dark matter and Dirac neutrinos from unbroken gauged B − L symmetry

Julio Leite,América Morales,José W.F Valle,Carlos A Vaquera-Araujo

doi:10.1016/j.physletb.2020.135537

Abstract

We propose a simple extension of the standard model where neutrinos get naturally small “scotogenic” Dirac masses from an unbroken gauged B−L symmetry, ensuring dark matter stability. The associated gauge boson gets mass through the Stueckelberg mechanism. Two scenarios are identified, and the resulting phenomenology briefly sketched.

Highlights

Amongst the major drawbacks of the Standard Model (SM) is the absence of neutrino mass and the lack of a viable dark matter candidate
[24] B − L extension of the standard model with naturally small neutrino masses. These are achieved through the scotogenic approach, while the unbroken B − L symmetry is responsible for both the Dirac nature of the neutrino mass and the stabilisation of a dark matter candidate
We suggest two standard model extensions with gauged B − L and dark matter as the mediator of neutrino mass generation

Summary

INTRODUCTION

Amongst the major drawbacks of the Standard Model (SM) is the absence of neutrino mass and the lack of a viable dark matter candidate. The symmetry stabilising dark matter could be closely related to neutrinos It could be an unbroken subgroup of the flavour symmetry that helps understand the neutrino oscillation parameters [14,15,16,17]. The dark matter stabilising symmetry could be a residual Zn subgroup of lepton number symmetry or B − L This may, again, lead to Dirac neutrinos. We study a Stueckelberg [24] B − L extension of the standard model with naturally small neutrino masses These are achieved through the scotogenic approach, while the unbroken B − L symmetry is responsible for both the Dirac nature of the neutrino mass and the stabilisation of a dark matter candidate.

TWO SCENARIOS

STUECKELBERG MECHANISM

SCOTOGENIC NEUTRINO MASSES

COMMENTS ON PHENOMENOLOGY