Sensitivity of the Cherenkov Telescope Array to a dark matter signal from the Galactic centre

TL;DR

This paper evaluates the Cherenkov Telescope Array's potential to detect TeV-scale dark matter signals from the Galactic centre, highlighting its unprecedented sensitivity and strategic observational approach.

Contribution

It provides an updated, comprehensive assessment of CTA's sensitivity to dark matter annihilation signals, considering various dark matter density profiles and systematic uncertainties.

Findings

CTA can significantly extend dark matter detection reach.

Sensitivity is sufficient even for cored density profiles.

The survey will map large-scale diffuse gamma-ray emission.

Abstract

We provide an updated assessment of the power of the Cherenkov Telescope Array (CTA) to search for thermally produced dark matter at the TeV scale, via the associated gamma-ray signal from pair-annihilating dark matter particles in the region around the Galactic centre. We find that CTA will open a new window of discovery potential, significantly extending the range of robustly testable models given a standard cuspy profile of the dark matter density distribution. Importantly, even for a cored profile, the projected sensitivity of CTA will be sufficient to probe various well-motivated models of thermally produced dark matter at the TeV scale. This is due to CTA's unprecedented sensitivity, angular and energy resolutions, and the planned observational strategy. The survey of the inner Galaxy will cover a much larger region than corresponding previous observational campaigns with imaging atmospheric Cherenkov telescopes. CTA will map with unprecedented precision the large-scale diffuse emission in high-energy gamma rays, constituting a background for dark matter searches for which we adopt state-of-the-art models based on current data. Throughout our analysis, we use up-to-date event reconstruction Monte Carlo tools developed by the CTA consortium, and pay special attention to quantifying the level of instrumental systematic uncertainties, as well as background template systematic errors, required to probe thermally produced dark matter at these energies. "Full likelihood tables complementing our analysis are provided here [ https://doi.org/10.5281/zenodo.4057987 ]"