Search for Boosted Dark Matter in COSINE-100.

Area of Science:

• Particle Physics
• Cosmology
• Astrophysics

Background:

• Boosted Dark Matter (BDM) is a theoretical dark matter candidate originating from the galactic center.
• Energetic electron recoils are a potential signature of BDM interactions.
• The COSINE-100 experiment utilizes NaI(Tl) crystal detectors to search for rare event signals.

Purpose of the Study:

• To search for energetic electron recoil signals from BDM using the COSINE-100 detector.
• To set limits on BDM interactions and explore specific dark sector models like dark photons.
• To compare the sensitivity of COSINE-100 with other dark matter experiments.

Main Methods:

• Analysis of 97.7 kg·yr exposure data from the COSINE-100 detector.
• Search for an excess of events with energies above 4 MeV.
• Setting limits on BDM interaction cross-sections and dark photon parameters.

Main Results:

• No significant excess of events above 4 MeV was observed.
• Competitive limits were set on the parameter space of dark photons, particularly for masses below 4 MeV.
• COSINE-100 shows advantages for low-mass dark matter searches compared to Super-Kamiokande.

Conclusions:

• The COSINE-100 experiment places constraints on BDM interactions.
• The detector demonstrates potential for future dark sector searches, especially for MeV electron recoils.
• Further analysis can refine limits and explore other dark sector models.