Explaining PAMELA and WMAP data through Coannihilations in Extended SUGRA with Collider Implications

Understand

The PAMELA positron excess is analyzed within the framework of nonuniversal SUGRA models with an extended $U(1)^n$ gauge symmetry in the hidden sector leading to neutralino dark matter with either a mixed Higgsino-wino LSP or an essentially pure wino dominated LSP.

• The Higgsino-wino LSP can produce the observed PAMELA positron excess and satisfy relic density constraints in the extended class of models due to a near degeneracy of the mass spectrum of the extended neutralino sector with the LSP mass.
• The simultaneous satisfaction of the WMAP relic density data and the PAMELA data is accomplished through a co-annihilation mechanism ($B_{\rm Co}-mechanism$), and leads to predictions of a neutralino and a chargino in the mass range (180-200) GeV as well as low lying sparticles accessible at colliders.
• We show that the models are consistent with the antiproton constraints from PAMELA as well as photon flux data from EGRET and FERMI-LAT.