1206.4758 (Lei Feng et al.)

Tentative wiggle in the cosmic ray electron/positron spectrum at $\sim$100 GeV: a dark matter annihilation signal in accordance with the 130 GeV $γ-$ray line?    [PDF]

Lei Feng, Qiang Yuan, Yi-Zhong Fan

Recently, a tentative 130 GeV $\gamma$-ray line signal was identified by quite a few groups. If correct it would constitute a "smoking gun" for dark matter annihilations. Interestingly, the spectra of the sum of cosmic ray electrons and positrons detected by ATIC and PAMELA both show small wiggle-like structure at $\sim 100$ GeV, which could be the result of the annihilation of $\sim 140$ GeV dark matter particles into electrons/positrons with a velocity-weighted cross section $<\sigma v>_{\rm \chi\chi\rightarrow e^{+}e^{-}}\sim 10^{-26}-10^{-25} {\rm cm^{3} s^{-1}}$. Accurate measurements of the total spectrum of electron and positron cosmic rays by AMS-2 and the upcoming missions such as DAMPE and CALET are highly needed to pin down the profile of the wiggle-like structure and then its physical origin.

View original: http://arxiv.org/abs/1206.4758