Eur. Phys. J. C (2006) 48: 627-632
https://doi.org/10.1140/epjc/s10052-006-0042-4

Theoretical Physics

Gamma rays from dark matter annihilation in the Draco and observability at ARGO

¹ Key laboratory of particle astrophysics, IHEP, Chinese Academy of Sciences, Beijing, 100049, P.R. China
² Theoretical Physics Division, IHEP, Chinese Academy of Sciences, Beijing, 100049, P.R. China

^* e-mail: bixj@mail.ihep.ac.cn

Received: 13 April 2006
Revised: 28 July 2006
Published online: 24 October 2006

Abstract

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∼400 GeV and a sharp central cuspy of the dark halo profile 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.