PAMELA/ATIC anomaly from exotic mediated dark matter decay

We discuss dark matter decay mediated by exotically charged particles (''exotics'') in a supersymmetric model with two dark matter (DM) components: one is the (bino-like) lightest supersymmetric particle (LSP) χ, and the other is a newly introduced meta-stable neutral singlet N. N decays to χe ⁺e ^- via a dimension 6 operator induced by a penguin-type one loop diagram with the life time of 10 ²⁶ sec., explaining energetic cosmic e ^± excess observed recently by PAMELA and ATIC/PPB-BETS. The superheavy masses of exotics ( ∼ 10 ^15-16 GeV) are responsible for the longevity of N. The superpartner of N develops the vacuum expectation value (VEV) of order TeV so that the DM N achieves the desired mass of 2 TeV. By the VEV, the U(1) _R symmetry is broken to the discrete Z ₂ symmetry, which is identified with the matter parity in the minimal supersymmetric standard model (MSSM). Since we have the two DM components, even extremely small amount of N [(10 ^-10) (n _N/n _χ)] could account for the observed positron flux with relatively light exotics' masses [10 ¹²GeV M _exo 10 ¹⁶ GeV].