Explorations of pseudo-Dirac dark matter having keV splittings and interacting via transition electric and magnetic dipole moments

TL;DR

This paper investigates a minimal pseudo-Dirac dark matter model with keV splittings, focusing on its production, detection prospects in xenon experiments, and constraints from various astrophysical and collider sources.

Contribution

It introduces a minimal inelastic dark matter model with transition dipole moments, analyzing its detection signatures and constraints from multiple experimental and cosmological observations.

Findings

XENONnT results exclude parts of the parameter space.

Next-generation xenon experiments can detect or further constrain the model.

The model predicts observable signatures from solar upscattering in direct detection.

Abstract

We study a minimal model of pseudo-Dirac dark matter, interacting through transition electric and magnetic dipole moments. Motivated by the fact that xenon experiments can detect electrons down to $\sim$\,keV recoil energies, we consider $\mathcal{O}$(keV) splittings between the mass eigenstates. We study the production of this dark matter candidate via the freeze-in mechanism. We discuss the direct detection signatures of the model arising from the down-scattering of the heavier state, that are produced in Solar upscattering, finding observable signatures at the current and near-future xenon based direct detection experiments. We also study complementary constraints on the model from fixed target experiments, lepton colliders, supernovae cooling and cosmology. We show that the latest XENONnT results rule out parts of the parameter space for this well motivated and minimal dark matter candidate. Next generation xenon experiments can either discover or further constrain how strongly inelastic dark matter can interact via the dipole moment operators.