Dark matter annihilations and decays after the AMS-02 positron
  measurements
  The AMS-02 collaboration has recently presented measurements of excellent
quality of the cosmic electron and positron fluxes as well as the positron
fraction. We use the measurements of the positron flux to derive, for the first
time, limits on the dark matter annihilation cross section and lifetime for
various final states. Working under the well-motivated assumption that a
background positron flux exists from spallations of cosmic rays with the
interstellar medium and from astrophysical sources, we find strong limits on
the dark matter properties which are competitive, although slightly weaker,
than those derived from the positron fraction. Specifically, for dark matter
particles annihilating only into e+ e- or into mu+ mu-, our limits on the
annihilation cross section are stronger than the thermal value when the dark
matter mass is smaller than 100 GeV or 60 GeV, respectively.
