Flavor-changing axions and Dirac neutrino masses

TL;DR

This paper explores a novel axion model within 3-3-1 extensions of the Standard Model, linking neutrino masses, dark matter, and the strong CP problem, with distinctive phenomenological signatures.

Contribution

It introduces a flavor-changing axion model connected to Dirac neutrino masses in 3-3-1 frameworks, highlighting unique couplings and decay processes.

Findings

Enhanced photon coupling of the axion.

Distinct fermion couplings compared to DFSZ and KSVZ models.

Potential flavor-changing meson decay signatures.

Abstract

Implementing the axion concept in the context of 3-3-1 extensions of the Standard Model (SM) leads to richer properties than in the simpler axion setups, and related to the Dirac neutrino seesaw mechanism. In this way the smallness of neutrino masses, the strong CP problem, the nature of dark matter and the number of families all have a common origin. Besides having an enhanced coupling to photons, our revamped axion can also be distinguished from DFSZ and KSVZ axions through its couplings to fermions. The latter lead to interesting phenomenological consequences, including flavor-changing axion-emitting two-body K, B and D meson decays.