Hunting for Heavy Charged Relics in Earth's Depths ✛ ✦
Context
Hypothetical charged massive particles (CHAMPs) are natural candidates for dark matter, arising in supersymmetric theories, extra-dimensional models, and hidden sectors. Collider searches for them are limited by collision energy, whereas the cosmological flux of such particles could carry information about physics beyond the Standard Model. Vera Rubin and Fritz Zwicky showed back in the last century that invisible matter dominates the Universe, and CHAMPs are one intriguing possibility for its nature. Previously they were sought in cosmic rays, meteorites, and lunar soil, while astrophysical constraints ranged from Big Bang nucleosynthesis to the stability of neutron stars and white dwarfs. However, a key problem—uncertainty in the exact distribution of stopped particles in natural reservoirs—left major gaps. Our approach quantitatively models, for the first time, the slowing-down and accumulation of CHAMPs in Earth, paving the way for robust terrestrial experiments.
Methods
We calculated the stopping-point distribution for CHAMPs falling onto Earth from the galactic halo, assuming a Maxwellian velocity distribution and using the Lindhard–Scharff formula for electromagnetic energy loss in matter. We then analyzed three target types: controlled water reservoirs (pools), natural materials—ice cores and ancient geological rocks. Enrichment can be done in two ways: gravitational sedimentation, leveraging the law of universal gravitation and Boltzmann distribution for heavy particles in a fluid, or centrifugation for lighter masses. Final CHAMP identification uses precision mass spectrometry, including charge-induced detection (CDMS), enabling measurement of anomalously low charge-to-mass ratios.
Results
The resulting stopping-depth map (see Fig. 3 of the original) shows that light CHAMPs (up to ~10⁴ TeV) mostly get stuck in the atmosphere and upper water layers, while particles with masses 10⁴–10⁹ TeV stop in the lithosphere at depths from meters to kilometers. For the heaviest (up to ~10¹² TeV), stopping occurs only via the low-velocity tail of the distribution. The sensitivity of the proposed method (Fig. 4) spans the CHAMP fraction in dark matter $f_X$ from 10⁻²⁰ at low masses down to ~10⁻¹⁰ at high masses, overlapping and significantly improving on existing limits. A pilot experiment with 1 liter of water and one centrifuge over one month of exposure can achieve $f_X$ ~ 10⁻¹⁰, while a year-long exposure of 10⁷ m³ of water with gravitational enrichment reaches $f_X$ ~ 10⁻¹⁸. For rocks hundreds of millions of years old, even a cubic-meter sample provides competitive sensitivity.
Implications
The protocol developed here opens a new era in heavy relic searches, turning Earth into a giant dark matter particle detector. It overcomes the main drawback of previous terrestrial searches—uncertainty about sample history—and provides a reproducible, scalable approach. This method can be immediately implemented in labs using mass spectrometry and centrifugation, and it promises to greatly widen the window into physics beyond the Standard Model.
Future development
In the near future, pilot experiments with controlled water reservoirs and ice cores are planned, along with optimization of enrichment protocols using hybrid gravitational-centrifugal schemes. Further development could include dedicated underground laboratories for analyzing deep rocks and the use of quantum sensors to detect individual passages of charged particles. CDMS technology will be refined for reliable detection of particles with masses up to 10¹² TeV.
Impact
The results will impact several fields: particle physics (the search for new physics), cosmology (the nature of dark matter), astrophysics (evolution of compact objects), and geophysics (new methods for rock dating and analysis). Multidisciplinary collaborations uniting physicists, geologists, and glaciologists may emerge.
Next steps
Immediate next steps include: (1) implementing a pilot experiment with a liter water sample; (2) selecting and characterizing suitable geological samples with known depth histories; (3) developing and testing special containers with a trapping coating (e.g., tin) to prevent loss of superheavy CHAMPs.
Key open problems
The search for CHAMPs is directly linked to one of the greatest unsolved problems in physics—identifying the particles that make up dark matter. It also touches on the naturalness problem in supersymmetric theories, the origin of baryon asymmetry, and the limits of collider experiments. Detecting heavy charged particles could shed light on Grand Unified Theories and the physics of the early Universe.
The knowledge machine's view
This section is addressed to the author of the paper and their colleagues. Neighbouring works were found by meaning-based search across our archive, not by word overlap. We do not review: we show the field around the work.
What the work does
This study develops a quantitative model for the deceleration and accumulation of charged massive particles (CHAMPs) in Earth's matter, calculates stopping-depth maps, and evaluates the method's sensitivity for water and geological reservoirs. A sample enrichment scheme (sedimentation, centrifugation) and particle identification via mass spectrometry are proposed.
Where its strength is
For the first time, a physically grounded stopping map for CHAMPs in terrestrial reservoirs is provided, transforming geochemical searches from heuristic to quantitatively predictive. This enables targeted selection of sampling sites and assessment of achievable sensitivity.
Where it could go next
- Modeling of deceleration in matter could be extended to include high-energy phase transitions, similar to how a related study considers quark droplet formation in neutron stars. This might alter predictions for stopping depths of the heaviest CHAMPs.based on: Stellar Droplets from Quark Soup arXiv:2605.18260
- The idea of searching for dark matter traces in ancient geological reservoirs could be compared with approaches that look for invisible particles via their imprint on the cosmic microwave background. Combining geochemical and cosmological constraints could close the CHAMP parameter space.based on: Invisible Particles Leave Their Mark on Ancient Light arXiv:2606.07106
Worth trying
- Investigate how the stopping map changes when inelastic nuclear interactions are included for CHAMPs with masses above 10^9 TeV, using approaches from quark matter physics.
- Assess whether CHAMPs stopped in ice cores could produce detectable radio signals upon annihilation, analogous to radio searches for dark matter.
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- Dark Matter from Bubblessimilarity 0.64
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- Invisible Particles Leave Their Mark on Ancient Lightsimilarity 0.62
- Dark Matter Speaks in Radio Wavessimilarity 0.62
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The closest work in the archive sits at 0.64 by meaning — the usual level for our corpus.
Original abstract
as written by the authors arXiv:2607.09845
We propose a method for detecting an ambient density of heavy, electrically-charged particles. Such particles would impact the Earth, lose energy in terrestrial matter, and become trapped. We study the accumulation of these rare particles in multiple target materials that provide large exposure, such as water and geological rocks. We discuss strategies for concentrating the particles by centrifugation or gravitational settling, along with particle identification using mass spectrometry. This method enables the discovery of charged relics with masses $$1-10^{12}\,{\rm TeV}$$ comprising a tiny fraction of the local dark matter density, reaching down to $$f_X\sim 10^{-20}$$ at the lowest masses. A pathfinder experiment using only a liter of water and one centrifuge (or $$\sim \text{m}^3$$ and no centrifuge) operating for a month can already reach $$f_X\sim 10^{-10}$$ and probe new parameter space.
If CHAMPs with a mass of 10¹⁰ TeV accumulated in a teaspoon, their total weight would be about a kilogram, like holding a chunk of a neutron star in your hand! And a pilot experiment with a month's exposure using a household centrifuge could spot particles that evade the Large Hadron Collider.
Key numbers
- typical virial velocity of dark matter: 10⁻³ c
- atmosphere thickness in rock equivalent: ~4 m
- Boltzmann height for m_X = 1 TeV in water: 230 m
- ultimate sensitivity f_X: up to 10⁻²⁰
- exposure duration for pilot experiment: 1 month