Prospects for Heavy WIMP Dark Matter with CTA: the Wino and Higgsino

TL;DR

This paper evaluates CTA's potential to detect heavy WIMP dark matter candidates, specifically Wino and Higgsino, at TeV energies, showing significant sensitivity improvements over current methods and highlighting the possibility of discovering thermal candidates.

Contribution

It provides the first detailed sensitivity forecasts for CTA detecting Wino and Higgsino dark matter, including background and Galactic emission considerations.

Findings

CTA can improve sensitivity to Wino by about an order of magnitude.

CTA has the potential to detect Higgsino as a thermal dark matter candidate.

Significant discovery potential for 1-100 TeV dark matter at CTA.

Abstract

TeV-scale particles that couple to the standard model through the weak force represent a compelling class of dark matter candidates. The search for such Weakly Interacting Massive Particles (WIMPs) has already spanned multiple decades, and whilst it has yet to provide any definitive evidence for their existence, viable parameter space remains. In this paper, we show that the upcoming Cherenkov Telescope Array (CTA) has significant sensitivity to uncharted parameter space at the TeV mass scale. To do so, we focus on two prototypical dark matter candidates, the Wino and Higgsino. Sensitivity forecasts for both models are performed including the irreducible background from misidentified cosmic rays, as well as a range of estimates for the Galactic emissions at TeV energies. For each candidate, we find substantial expected improvements over existing bounds from current imaging atmospheric Cherenkov telescopes. In detail, for the Wino we find a sensitivity improvement of roughly an order of magnitude in $\langle \sigma v \rangle$, whereas for the Higgsino we demonstrate that CTA has the potential to become the first experiment that has sensitivity to the thermal candidate. Taken together, these enhanced sensitivities demonstrates the discovery potential for dark matter at CTA in the 1-100 TeV mass range.