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It is shown that a Weakly Interacting Massive dark matter Particle (WIMP) interpretation for the positron excess observed in a variety of experiments, HEAT, PAMELA, and AMS-02, is highly constrained by the Fermi/LAT observations of dwarf galaxies. In particular, this paper has focused on the annihilation channels that best fit the current AMS-02 data (Boudaud et al., 2014). The Fermi satellite has surveyed the $gamma$-ray sky, and its observations of dwarf satellites are used to place strong bounds on the annihilation of WIMPs into a variety of channels. For the single channel case, we find that dark matter annihilation into {$bbar{b}$, $e^+e^-$, $mu^+mu^-$, $tau^+tau^-$, 4-$e$, or 4-$tau$} is ruled out as an explanation of the AMS positron excess (here $b$ quarks are a proxy for all quarks, gauge and Higgs bosons). In addition, we find that the Fermi/LAT 2$sigma$ upper limits, assuming the best-fit AMS-02 branching ratios, exclude multichannel combinations into $bbar{b}$ and leptons. The tension between the results might relax if the branching ratios are allowed to deviate from their best-fit values, though a substantial change would be required. Of all the channels we considered, the only viable channel that survives the Fermi/LAT constraint and produces a good fit to the AMS-02 data is annihilation (via a mediator) to 4-$mu$, or mainly to 4-$mu$ in the case of multichannel combinations.
Several studies have pointed out an excess in the AMS-02 antiproton spectrum at rigidities of 10-20 GV. Its spectral properties were found to be consistent with a dark-matter particle of mass 50-100 GeV which annihilates hadronically at roughly the t
An excess of $gamma$ rays in the data measured by the Fermi Large Area Telescope in the direction of the Galactic center has been reported in several publications. This excess, labeled as the Galactic center excess (GCE), is detected analyzing the da
The AMS-02 collaboration has recently released data on the positron fraction $e^+/(e^-+e^+)$ up to energies of about 350 GeV. If one insists on interpreting the observed excess as a dark matter signal, then we find it is best described by a TeV-scale
Observation of gamma-rays from dwarf galaxies is an effective way to search for particle dark matter. Using 4-year data of Fermi-LAT observations on a series of Milky Way satellites, we develop a general way to search for the signals from dark matter
For explaining the AMS-02 cosmic positron excess, which was recently reported, we consider a scenario of thermally produced and decaying dark matter (DM) into the standard model (SM) leptons with an extremely small decay rate, Gamma_{DM} sim 10^{-26}