Optimal Celestial Bodies for Dark Matter Detection

TL;DR

This paper compares various celestial bodies as dark matter detectors, analyzing their effectiveness and constraints, and proposes a new search strategy using the Galactic center stellar population for improved sensitivity.

Contribution

It systematically evaluates the detection potential of different celestial objects and introduces a novel Galactic center stellar population search strategy for dark matter detection.

Findings

Different objects are optimal in different regimes.

New constraints on dark matter annihilation and mediator properties.

Galactic center stars can outperform the Sun in detection sensitivity.

Abstract

A wide variety of celestial bodies have been considered as dark matter detectors. Which stands the best chance of delivering the discovery of dark matter? Which is the most powerful dark matter detector? We investigate a range of objects, including the Sun, Earth, Jupiter, Brown Dwarfs, White Dwarfs, Neutron Stars, Stellar populations, and Exoplanets. We quantify how different objects are optimal dark matter detectors in different regimes by deconstructing some of the in-built assumptions in these search sensitivities, including observation potential and particle model assumptions. We find new constraints and future sensitivities across a range of dark matter annihilation final states. We quantify mediator properties leading to detectable celestial-body energy injection or Standard Model fluxes, and show how different objects can be expected to deliver corroborating signals. We discuss different search strategies, their opportunities and limitations, and the interplay of regimes where different celestial objects are optimal dark matter detectors. Deconstructing the assumptions of these searches leads us to point out a new search using the Galactic center stellar population that can provide greater sensitivity to the dark matter-nucleon scattering cross section than the Sun, despite being significantly further away in our Galaxy.