Wobbly Dark Matter Signals at Cherenkov Telescopes from Long-Lived Mediator Decays

Area of Science:

• Astrophysics
• Particle Physics
• Cosmology

Background:

• Imaging Atmospheric Cherenkov Telescopes (IACTs) use "wobble mode" for dark matter detection, observing signal and background regions simultaneously.
• This strategy is potentially compromised by dark matter models involving long-lived mediators that decay into detectable gamma rays.

Purpose of the Study:

• To investigate the impact of long-lived mediators on IACT observations.
• To identify novel features and opportunities for dark matter detection arising from such scenarios.

Main Methods:

• Analysis of gamma-ray data considering signal contamination in background regions.
• Examination of spectral changes with observing direction and high-energy excesses.

Main Results:

• Long-lived mediators can lead to signal contamination in background control regions.
• Gamma-ray spectra exhibit directional dependence and hard excesses at high energies.
• These features deviate significantly from standard dark matter detection paradigms.

Conclusions:

• The presence of long-lived mediators offers unique observational signatures for dark matter searches.
• These signatures provide new methods for identifying dark matter signals and determining its properties.