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Resonant Axion-Plasmon Conversion in Neutron Star Magnetospheres
H Terças1,2, J T Mendonça2, R Bingham3,4
1Instituto Politécnico de Lisboa, Instituto Superior de Engenharia de Lisboa, Rua Conselheiro Emídio Navarro, 1959-007 Lisboa, Portugal.
Physical Review Letters
|September 26, 2025
Summary
Resonant axion-plasmon conversion in magnetars reduces expected radio signals for dark-matter axion detection. This necessitates reassessing current experimental constraints and refining future astrophysical axion search strategies.
Area of Science:
- Astrophysics
- Particle Physics
- Cosmology
Background:
- Magnetars possess strong magnetic fields and dense plasma environments.
- Axions are hypothetical dark matter particles that can convert to photons.
- Previous dark matter searches focused on axion-photon conversion without considering plasmon interactions.
Purpose of the Study:
- To investigate the impact of resonant axion-plasmon conversion on axion-photon signals from magnetars.
- To determine how this conversion affects dark-matter axion detection sensitivities.
- To re-evaluate experimental constraints for astrophysical axion searches.
Main Methods:
- Theoretical analysis of resonant axion-plasmon conversion within magnetar magnetospheres.
- Modeling the modification of axion-photon conversion rates and resulting photon flux.
- Assessing the impact on radio telescope sensitivities and exclusion regions.
Main Results:
- Resonant axion-plasmon conversion introduces nonradiative power loss, diminishing photon flux.
- This effect reduces the sensitivity of radio telescopes for axion detection.
- The conversion modifies expected radio signals, potentially shifting exclusion regions for experiments.
Conclusions:
- Axion-plasmon conversion is a critical factor in magnetar environments affecting axion detection.
- Current experimental constraints may need revision due to these plasmon effects.
- Future dark matter axion experiments must incorporate these findings for improved strategies.
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