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 $\gamma$-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 5$\sigma$ signal, we reconstruct the annihilation ratios for five 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 $\gamma$-ray astronomy. This approach shows that for masses between 0.3-5 TeV we can probe values below the thermal relic velocity annihilation weighted cross-section allowing a 2$\sigma$ detection for 525 hours of simulated observation data by the Cherenkov Telescope Array Observatory of the Galactic Centre.