Fermi telescope does not confirm DM claims
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Fermi Space Telescope (image by NASA)
Fermi gamma-ray space telescope was unable to predict the presence of the 300-800 GeV peak in the distribution function of high energy electrons in cosmic rays. Let me remind you that the anomaly we are talking about was claimed to be found by the ATIC team and generated recently a lot of buzz in high energy physics community (one source of those high energy electrons may be decay of dark matter particles).
It is interesting to note two things in this respect:
a) “Fermi” detected about 4 million events in the corresponding window of energy, while ATIC – only some hundreds of thousands. Can the excess that ATIC have seen be related to some effect in the atmosphere? (just kidding)
b) On the other hand, “Fermi” detectors are actually less sensible in the 300-800 GeV window we are interested in than ATIC detectors, that is, we naturally may expect to find bumps in “Fermi” data where ATIC has seen a well expressed peak. Some people say that indeed see those bumps 
c) ATIC team is not the only one who claimed they’ve detected the anomaly – PAMELA has also seen some increase in ratio of positrons over electrons at lower energies (and PAMELA is also the space mission).
Update: the paper by Fermi/LAT collaboration is online: “Measurement of the Cosmic Ray e+ plus e- spectrum from 20 GeV to 1 TeV with the Fermi Large Area Telescope”.
So, it seems we have quite a controversy here
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