Model-independent dark matter detection with the Cherenkov Telescope Array Observatory

Abstract Searches for annihilating dark matter are often designed with a specific dark matter candidate in mind. However, the space of potential dark matter models is vast, which raises the question: how can we search for dark matter without making strong assumptions about unknown physics. We present a model-independent approach for measuring dark matter annihilation ratios and branching fractions with γ-ray event data. By parameterizing the annihilation ratios for seven different channels, we obviate the need to search for a specific dark matter candidate. To demonstrate our approach, we analyse simulated data using the GammaBayes pipeline. Given a 5σ significance of a dark matter signal in the data, we reconstruct the dominant individual annihilation ratios for dominant channels to within 95% credibility. This allows us to reconstruct dark matter annihilation/decay channels without presuming any particular model, thus offering a model-independent approach to indirect dark matter searches in γ-ray astronomy. This approach shows that for masses between 0.3–2.5 TeV we can probe values below the thermal relic velocity-weighted annihilation cross-section allowing a 2σ detection for 525 hours of simulated observation data by the Cherenkov Telescope Array Observatory of the Galactic Centre.