Chinese Acad Sci, Key Lab Particle Astrophys, IHEP, Beijing 100049, Peoples R China
; Chinese Acad Sci, Div Phys Theor, IHEP, Beijing 100049, Peoples R China
The CACTUS experiment recently observed a gamma ray excess above 50 GeV from the direction of the Draco dwarf spheroidal galaxy. Considering that Draco is dark matter dominated, the gamma rays may be generated through dark matter annihilation in the Draco halo. In the framework of the minimal supersymmetric extension of the standard model we explore the parameter space to account for the gamma ray signals at CACTUS. We find that the neutralino mass is constrained to be approximately in the range between 100 GeV similar to 400 GeV and a sharp central cuspy of the dark halo pro. le in Draco is necessary to explain the CACTUS results. We then discuss further constraints on the supersymmetric parameter space by observations at the ground-based ARGO detector. It is found that the parameter space can be strongly constrained by ARGO if no excess from Draco is observed above 100 GeV.