Ultra-Heavy Dark Matter Search with Electron Microscopy of Geological Quartz

TL;DR

This paper proposes using electron microscopy of ancient quartz to detect ultra-heavy dark matter through distinctive damage tracks, leveraging geological timescales and high-resolution imaging for background rejection.

Contribution

It introduces a novel detection method for ultra-heavy dark matter using geological quartz and electron microscopy, combining large exposure with high-fidelity background discrimination.

Findings

Quartz samples can serve as effective UHDM detectors.

Damage tracks provide a distinctive signature for UHDM detection.

The method offers a new avenue for probing low-number-density dark matter.

Abstract

Self-interactions within the dark sector could clump dark matter into heavy composite states with low number density, leading to a highly suppressed event rate in existing direct detection experiments. However, the large interaction cross section between such ultra-heavy dark matter (UHDM) and standard model matter results in a distinctive and compelling signature: long, straight damage tracks as they pass through and scatter with matter. In this work, we propose using geologically old quartz samples as large-exposure detectors for UHDM. We describe a high-resolution readout method based on electron microscopy, characterize the most favorable geological samples for this approach, and study its reach in a simple model of the dark sector. The advantage of this search strategy is two-fold: the age of geological quartz compensates for the low number density of UHDMs, and the distinct geometry of the damage track serves as a high-fidelity background rejection tool.