Dark Matter Search in a Proton Beam Dump with MiniBooNE.

Area of Science:

• Particle Physics
• Cosmology
• Astroparticle Physics

Background:

• Dark matter remains one of the most significant mysteries in physics.
• Vector-portal models propose dark matter interacting via a heavy vector boson.
• Proton beam dump experiments offer a unique avenue for dark matter detection.

Purpose of the Study:

• To search for dark matter produced via vector-boson mediation at the Fermilab Booster.
• To constrain dark matter properties, specifically its mass and interaction strength.
• To establish new limits on dark matter cross-sections in a specific mass range.

Main Methods:

• Utilized the Fermilab 8-GeV Booster proton beam directed at a steel beam dump.
• Employed the MiniBooNE detector, located 490m downstream, to detect dark matter via elastic scattering.
• Applied analysis techniques from previous MiniBooNE scattering results and analyzed multiple datasets to mitigate systematic errors.

Main Results:

• No significant excess of events above the expected background was observed.
• Established a 90% confidence limit on the dark matter cross-section parameter Y ≲ 10⁻⁸ for dark matter masses between 0.01 and 0.3 GeV.
• Achieved the best limits from a dedicated proton beam dump search in this mass and coupling range.

Conclusions:

• The MiniBooNE-DM search sets stringent new limits on light dark matter models.
• The results demonstrate the efficacy of beam dump experiments for dark matter searches.
• This approach extends dark matter detection capabilities to lower mass ranges relevant for direct detection experiments.