Dark Matter Signals from Timing Spectra at Neutrino Experiments

Area of Science:

• Particle Physics
• Cosmology
• Experimental Physics

Background:

• Searching for new physics beyond the Standard Model is a key goal in particle physics.
• Dark matter (DM) remains one of the biggest mysteries, with its nature yet to be discovered.
• Neutrino experiments offer unique opportunities to probe dark matter candidates.

Purpose of the Study:

• To propose a novel strategy for detecting new physics, specifically dark matter, using timing spectra in low-energy neutrino experiments with a pulsed beam.
• To investigate the discovery potential for dark matter from dark photon decay within the COHERENT experiment.
• To explore the parameter space of dark matter candidates using existing and future experimental data.

Main Methods:

• Utilizing a pulsed beam to create a "resonancelike" timing distribution for signals from decaying new particles.
• Analyzing event timing distributions to isolate potential dark matter signals from background noise.
• Applying timing and energy cuts to existing CsI detector data from the COHERENT experiment.

Main Results:

• An excess in the timing distribution of COHERENT CsI data was observed for the first time, consistent with dark matter from dark photon decay.
• Demonstrated the potential for this "resonancelike" signal to be isolated from uniform backgrounds.
• Compared the sensitivity to the kinetic mixing parameter (ε) with projected limits from other experiments like LDMX and DUNE.

Conclusions:

• The proposed timing strategy offers a promising new avenue for dark matter searches at low-energy neutrino experiments.
• The COHERENT experiment shows exciting prospects for exploring dark matter parameter space, particularly for dark matter originating from dark photon decay.
• This work provides a foundation for future dark matter searches using timing signatures in various experimental settings.