Axion-like particles from soft supersymmetry breaking

TL;DR

This paper explores a supersymmetric effective field theory where soft supersymmetry-breaking effects generate a heavy axion-like particle, analyzing its spectrum and potential experimental and cosmological implications.

Contribution

It introduces a framework where ALP masses are controlled by supersymmetry-breaking scale, providing a new perspective on heavy ALP phenomenology without a specific UV completion.

Findings

ALP mass is predominantly set by soft SUSY-breaking effects.

The spectrum includes ALP, saxion, and axino with phenomenological relevance.

Potential signals in laboratory, astrophysics, and cosmology are discussed.

Abstract

We study a supersymmetric effective field theory in which the mass of an axion-like particle (ALP) is generated predominantly by soft supersymmetry-breaking effects. The Peccei--Quinn symmetry is exact in the supersymmetric limit and is explicitly broken only by soft terms induced by supergravity, leading to a naturally heavy ALP whose mass is controlled by the supersymmetry-breaking scale. We analyze the resulting ALP, saxion, and axino spectrum and investigate the phenomenological implications for laboratory searches, astrophysical observations, and cosmology. The framework is treated as an effective field theory without specifying a unique ultraviolet completion, and no attempt is made to explain the origin of a small strong CP phase, which is assumed to be suppressed by ultraviolet physics or by an independent mechanism. Instead, the focus is on the generic and testable phenomenology of heavy axion-like particles whose masses arise from supersymmetry breaking.