Proposal for Direct Detection of Ultralight Dark Matter via Charged Lepton Flavor Violation.

Summary

This paper proposes a novel direct detection strategy for ultralight dark matter by searching for modulated charged lepton flavor violating decays at accelerator-based experiments.

Key findings

• Ultralight dark matter can induce time-dependent modulations in rare exotic decays.
• Charged lepton flavor violating decays like μ→eϕ' and τ→e(μ)ϕ' can inherit this modulation.
• Sufficient event samples at Mu3e, Belle-II, and FCC-ee could enable detection of ultralight dark matter.

Methods

• Analysis of charged particle decays at accelerator-based experiments.
• Searching for modulations in rare exotic decays (μ→eϕ', τ→e(μ)ϕ').
• Utilizing event samples from Mu3e, Belle-II, and FCC-ee.

Limitations

• The proposed method relies on specific couplings of dark matter to Standard Model particles.
• The abundance of ultralight dark matter must be consistent with a misalignment mechanism.
• Requires sufficient event samples for statistically significant detection.

Applications

• Direct detection of ultralight dark matter.
• Probing dark matter candidates with masses significantly below eV.
• Enhancing the physics reach of current and future collider experiments.