Constraints on Light Dark Matter Particles Interacting with Electrons from DAMIC at SNOLAB

Area of Science:

• Particle Physics
• Astrophysics
• Cosmology

Background:

• Dark matter remains one of the most significant mysteries in physics.
• Direct detection experiments aim to observe dark matter particles interacting with ordinary matter.
• Previous searches have primarily focused on higher mass dark matter candidates.

Purpose of the Study:

• To place direct-detection constraints on light dark matter particles (0.6-100 MeV/c^2) interacting with electrons.
• To explore previously unconstrained parameter space for dark matter candidates.
• To provide new constraints on hidden-photon dark matter (1.2-30 eV/c^2).

Main Methods:

• Utilizing the extremely low leakage current of the DAMIC (Dark Matter in CCDs) detector at SNOLAB.
• Analyzing the charge distribution of detector pixels collecting fewer than 10 electrons.
• Attributing signals beyond detector noise to potential dark matter interactions.

Main Results:

• Established direct-detection constraints on light dark matter particles interacting with electrons.
• Constrained unexplored parameter space for dark matter masses between 0.6 and 100 MeV/c^2.
• Presented new constraints for hidden-photon dark matter in the 1.2-30 eV/c^2 mass range.

Conclusions:

• The DAMIC detector's low leakage current enables sensitive searches for light dark matter.
• This research expands the reach of direct detection experiments to lower dark matter mass regimes.
• New limits are set on specific dark matter models, guiding future theoretical and experimental efforts.