GeV-Scale Messengers of Planck-Scale Dark Matter

TL;DR

This paper proposes a model where Planck-scale dark matter interacts via a GeV-scale messenger gauge boson, enabling potential detection through low-energy experiments and connecting high-energy physics with observable phenomena.

Contribution

It introduces a new low-mass gauge boson as a messenger linking Planck-scale dark matter to the Standard Model, with testable predictions for direct detection and kinetic mixing.

Findings

Potential for direct detection via U(1)_d interactions

Measurable kinetic mixing between U(1)_d and photon

Astrophysical constraints limit DM mass to below 10^{17} GeV

Abstract

If dark matter (DM) originates from physics near the Planck scale it could be directly detected via its multiple scattering signals, yet this requires a large cross section for DM interactions with atoms. Hence, detection of such DM could imply mediation by new low mass messengers. We propose that a dark $U(1)_d$ remnant of the underlying spacetime geometry or a unified theory may survive down to small mass scales $\sim 1$ GeV, connecting low energy Standard Model (SM) and Planck scale phenomena. Typical required cross sections for direct detection of Planck scale DM can be achieved through the $U(1)_d$ interactions of DM with SM quarks. Low energy intense sources may uncover the GeV scale messengers of Planckian physics, allowing for testable predictions. We assume that $U(1)_d$ is gauged baryon number, which implies several new electroweak charged particles are expected to arise near the weak scale to cancel gauge anomalies. The model generically gives rise to kinetic mixing between the $U(1)_d$ gauge boson and the photon, which may be measurable. In this scenario, direct detection of DM and measurements of a low energy messenger, including its kinetic mixing with the photon, can potentially shed light on the high energy character of the scenario. Astrophysical considerations related to white dwarf stability against runaway nuclear fusion potentially disfavor DM heavier than $\sim 10^{17}$ GeV within our assumed messenger model.