Discriminate different scenarios to account for the PAMELA and ATIC data by synchrotron and IC radiation

Abstract

The positron excess observed at PAMELA and the "bump" at the electron spectrum from 300GeV-800GeV observed by ATIC indicate existence of primary electron and positron sources. We show that the three scenarios, that is, the annihilating DM, decaying DM and pulsars, can all interpret the two experimental results simultaneously by taking proper parameters. Then we study the synchrotron and inverse Compton (IC) radiation produced by the primary electron/positrons. We find the three scenarios predict different spectra of the synchrotron and IC radiation at the Galactic center (GC) region as well as different longitude and latitude profiles. An all-sky survey between the band $10^4 \sim 10^9$MHz can clearly discriminate the three scenarios. The diffuse $\gamma$ rays in the three scenarios are consistent with the EGRET result. However, annihilating DM shows obvious excess beyond the background above $\sim 10 GeV$, while the other two show much less excess. The future Fermi/GLAST result on $\gamma$ rays can also help to distinguish from these scenarios.