Sub-GeV Dark Matter Direct Detection with Neutrino Observatories

Area of Science:

• Particle Physics
• Astrophysics
• Cosmology

Background:

• Dark matter (DM) constitutes a significant portion of the universe's mass but remains undetected.
• Current detection methods for low-mass dark matter (sub-GeV) face significant challenges.
• Neutrino observatories possess large target masses and sensitive detectors.

Purpose of the Study:

• To propose a new technique for searching sub-gigaelectronvolt (sub-GeV) dark matter.
• To explore a novel application of neutrino observatories for dark matter detection.
• To leverage the annual modulation signature of dark matter to overcome background noise.

Main Methods:

• Utilizing dark matter-electron scattering within a detector's target material.
• Detecting scintillation light produced by excited or ionized target molecules using photomultiplier tubes (PMTs).
• Isolating the dark matter signal by analyzing the aggregate scattering rate and its expected annual modulation, distinguishing it from the PMT dark rate.

Main Results:

• Demonstrated the feasibility of the technique using the JUNO (20,000-ton scintillator) detector as an example.
• Showcased the potential for significant sensitivity in specific dark matter mass ranges.
• Indicated that the proposed method can surpass the sensitivity of other existing techniques in certain regimes.

Conclusions:

• The proposed technique offers a promising new avenue for sub-GeV dark matter searches.
• Neutrino observatories can be effectively repurposed for dark matter detection.
• The method's sensitivity reaches important benchmarks set by particle theory, potentially leading to new discoveries.