Dirac neutrinos from Peccei-Quinn symmetry: a fresh look at the axion

TL;DR

This paper proposes a simple solution linking the strong CP problem to Dirac neutrinos, using a Dirac seesaw mechanism, and explores how neutrino mass limits can inform axion parameter space beyond current experimental reach.

Contribution

It introduces a novel connection between the strong CP problem and Dirac neutrinos via a straightforward model involving the Peccei-Quinn symmetry.

Findings

Neutrino masses are generated through a Dirac seesaw mechanism.

Neutrino mass limits can constrain axion parameters.

The model links axion physics with neutrino mass generation.

Abstract

We show that a very simple solution to the strong CP problem naturally leads to Dirac neutrinos. Small effective neutrino masses emerge from a type I Dirac seesaw mechanism. Neutrino mass limits probe the axion parameters in regions currently inaccessible to conventional searches.