Ma-xion: Majoron as QCD axion in a radiative seesaw model

TL;DR

This paper proposes a unified model where the Majoron acts as the QCD axion, linking neutrino mass generation, the strong CP problem, and dark matter within a radiative seesaw framework using color adjoint mediators.

Contribution

It introduces a novel model where the Majoron serves as the QCD axion, connecting neutrino mass, CP violation, and dark matter in a radiative seesaw setup.

Findings

Majoron doubles as QCD axion solving strong CP problem

Model links neutrino mass scale with Peccei-Quinn symmetry breaking

Dark matter candidate identified as the axion

Abstract

The smallness of neutrino mass, the strong CP problem, and the existence of dark matter are explained in an economical way. The neutrino mass is generated by the colored version of a radiative seesaw mechanism by using color adjoint mediators. The Majorana mass term of the adjoint fermion, which carries lepton number U(1)_L, is induced by its spontaneous breaking, resulting in a Majoron which doubles as the QCD (quantum chromodynamics) axion, thereby solving the strong CP problem. The breaking of U(1)_L sets simultaneously the seesaw scale for neutrino mass and the Peccei-Quinn breaking scale. This axion is a good candidate for dark matter as usually assumed.