Axion mass prediction from minimal grand unification

TL;DR

This paper links the axion mass to grand unification scale within a minimal SU(5) model, predicting a specific mass range that can be tested by upcoming dark matter experiments, offering potential indirect evidence for grand unification.

Contribution

It introduces a minimal SU(5) model implementing the Peccei-Quinn mechanism with axion mass predictions connected to grand unification constraints.

Findings

Predicted axion mass range: 4.8 to 6.6 neV.

Relaxed upper bound up to 330 neV with tuning.

Axion mass window testable by future dark matter experiments.

Abstract

We propose a minimal realization of the Peccei Quinn mechanism in a realistic SU(5) model, where the axion mass is directly connected to the grand-unification scale. By taking into account constraints from proton decay, collider searches and gauge coupling unification, we predict the axion mass: $m_a \in [4.8, 6.6]$ neV. The upper bound can be relaxed up to $m_a < 330$ neV, at the cost of tuning the flavour structure of the proton decay operators. The predicted mass window will be complementarily probed by the axion dark matter experiments ABRACADABRA and CASPER-Electric, which could provide an indirect evidence for the scale of grand unification before the observation of proton decay.