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Cavendish Tests of Millicharged Particles
Asher Berlin1,2, Zachary Bogorad1,2, Peter W Graham3,4
1Fermi National Accelerator Laboratory, Theory Division, Batavia, Illinois 60510, USA.
Physical Review Letters
|July 26, 2026
Summary
Cavendish tests can detect millicharged particles, a potential dark matter component. Reinterpreting these experiments provides strong bounds, and proposed modifications could outperform future accelerator searches.
Area of Science:
- Particle Physics
- Cosmology
- Experimental Physics
Background:
- Terrestrial millicharged particles may exist as dark matter or from cosmic ray showers.
- Electrified shells can significantly enhance the local density of these particles.
- Cavendish tests of Coulomb's Law have a long history dating back to the late 18th century.
Purpose of the Study:
- To demonstrate that historical Cavendish tests can act as accumulators and detectors for millicharged particles.
- To establish new bounds on terrestrial millicharged particle populations by reinterpreting existing Cavendish test data.
- To propose an enhanced Cavendish test setup for improved sensitivity and potential detection of cosmic ray-generated millicharged particles.
Main Methods:
- Reinterpreting historical Cavendish experiment data to search for signals of millicharged particles.
- Proposing a modified Cavendish test apparatus with an additional charged shell to enhance sensitivity.
- Analyzing the potential of this enhanced setup to detect irreducible densities of millicharged particles.
Main Results:
- Historical Cavendish tests provide some of the strongest existing bounds on terrestrial millicharged particle populations.
- A modified Cavendish test with an additional charged shell significantly improves sensitivity.
- The proposed method, using established technology, could surpass future accelerator searches for sub-GeV mass particles.
Conclusions:
- Cavendish tests are powerful tools for probing terrestrial millicharged particle populations.
- Modified Cavendish tests offer a cost-effective and sensitive approach to dark matter detection.
- This approach has the potential to yield significant discoveries in particle physics using existing experimental frameworks.
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