CPon Dark Matter

TL;DR

This paper explores a supersymmetric model where a light scalar field, the CPon, can serve as a viable dark matter candidate, satisfying astrophysical and experimental constraints within a specific mass range.

Contribution

It introduces the CPon as a dark matter candidate in supersymmetric models with spontaneous CP violation, analyzing its couplings, constraints, and production mechanisms.

Findings

CPon mass range between 10 meV and 1 MeV.

CPon can account for dark matter via misalignment and freeze-in production.

Couplings suppressed by UV scale > 10^{12} GeV.

Abstract

We study a class of supersymmetric models where the strong CP problem is solved through spontaneous CP violation, carried out by a complex scalar field that determines the Yukawa couplings of the theory. Assuming that one real component of this field - the CPon - is light, we examine the conditions under which it provides a viable Dark Matter candidate. The CPon couplings to fermions are largely determined by the field-dependent Yukawa interactions, and induce couplings to gauge bosons at 1-loop. All couplings are suppressed by an undetermined UV scale, which needs to exceed $10^{12}$ GeV in order to satisfy constraints on excessive stellar cooling and rare kaon decays. The CPon mass is limited from below by 5th force experiments and from above by X-ray telescopes looking for CPon decays to photons, leaving a range roughly between 10 meV and 1 MeV. Everywhere in the allowed parameter space the CPon can saturate the observed Dark Matter abundance through an appropriate balance of misalignment and freeze-in production from heavy SM fermions.