Neutrino-axion-dilaton interconnection

Understand

We show that a recently proposed framework that provides a simple connection between Majorana neutrinos and an invisible axion in minimal scalar extensions of the standard electroweak model can be naturally embedded in a classically scale-invariant setup.

• The explicit breaking of the scale invariance \`a la Coleman-Weinberg generates the Peccei-Quinn and electroweak scales.
• The spontaneous breaking of the chiral $U(1)_{PQ}$ triggers the generation of neutrino masses via Type-II seesaw and, at the same time, provides a dynamical solution to the strong CP problem as well as the axion as a dark matter candidate.
• The electroweak and neutrino mass scales are obtained via a technically natural ultraweak limit of the singlet scalar interactions.