Speaker
Description
Higgsino dark matter (DM) is a well-motivated candidate in supersymmetric theories, with a 1.1 TeV thermal higgsino naturally accounting for the observed DM abundance. Despite its strong theoretical foundation, detecting the higgsino remains challenging.
Direct detection is hindered by its suppressed scattering cross-section and theoretical uncertainties on contaminated background, complicating signal discrimination. Collider searches require extremely high-energy facilities, such as a 100 TeV hadron collider or a 10 TeV muon collider, due to the higgsino’s weak coupling and high mass. Given these challenges, alternative detection strategies—particularly indirect searches via high-energy astrophysical observations—are crucial.
The Cherenkov Telescope Array Observatory (CTAO), with CTAO-North in La Palma, Spain, and CTAO-South in Atacama, Chile, offers a promising indirect detection approach by probing gamma rays from potential DM annihilation, particularly in the Galactic Center. CTAO-North has achieved the first light with its first Large-Sized Telescope (LST), while CTAO-South, expected to be fully operational in the 2030s, will observe the Galactic Center under optimal conditions. Alternatively, CTAO-North can observe the Galactic Center at so-called large zenith angles —tracking the Galactic Center along the horizon— enhancing sensitivity at TeV energies at the cost of a higher energy threshold. With this observation mode, we regard that CTAO-North is capable of complementing the CTAO-South view.
Using CTAO simulations of instrument responses, this study projects sensitivity of higgsino searches with CTAO-North and CTAO-South under a realistic observational timeline. In particular, considering the phased construction, we assume a two-stage telescope configuration for CTAO-North: the LST sub-array and the planned full array. Notably, our projections indicate that CTAO-North could achive the required sensitivity within the next decade, reinforcing gamma-ray observations as a viable method for higgsino DM detection. The findings and their implications are presented in this contribution.