SENSEI: First Direct-Detection Constraints on Sub-GeV Dark Matter from a Surface Run

Area of Science:

• Particle physics
• Astrophysics
• Experimental physics

Background:

• Dark matter interactions with electrons are a key area of research.
• Skipper-CCD technology offers enhanced sensitivity for detecting low-energy events.
• Previous experiments have not focused on electron recoil detection for sub-GeV dark matter.

Purpose of the Study:

• To present the first results from a prototype Sub-Electron-Noise Skipper CCD Experimental Instrument (SENSEI).
• To search for sub-GeV dark matter particles interacting with electrons in silicon via electron recoils.
• To establish new direct-detection constraints for dark matter particle candidates.

Main Methods:

• Utilized a prototype SENSEI detector employing Skipper-CCD technology.
• Collected 0.019 gram-days of commissioning data above ground at Fermi National Accelerator Laboratory.
• Analyzed data for signals consistent with electron recoils from dark matter interactions.

Main Results:

• Established new direct-detection constraints for dark matter particles in the mass range of approximately 500 keV to 4 MeV.
• Disallowed previously allowed strongly interacting dark matter particles (masses ~500 keV to a few hundred MeV) due to surface data.
• Demonstrated the capability of Skipper-CCD technology for dark matter searches.

Conclusions:

• The SENSEI experiment successfully set new constraints on sub-GeV dark matter.
• The results highlight the potential of Skipper-CCD technology for future dark matter detection experiments.
• The findings have implications for various dark matter models, including those related to the EDGES anomaly.