Hints of a charge asymmetry in the electron and positron cosmic-ray excesses

By combining the recent data from AMS-02 with those from Fermi-LAT, we show the emergence of a charge asymmetry in the electron and positron cosmic-ray excesses, slightly favoring the electron component. Astrophysical and dark matter inspired models introduced to explain the observed excesses can be classified according to their prediction for the charge asymmetry and its energy dependence. Future data confirming the presence of a charge asymmetry would imply that an asymmetric production mechanism is at play. © 2013 American Physical Society.