Jin, HB (reprint author), State Key Lab Theoret Phys, Beijing 100190, Peoples R China.
The first measurement on the antiproton to proton ratio by the AMS-02 collaboration agrees with the expectation from conventional cosmic-ray secondaries in the kinetic energy range similar to 20-100 GeV, which can be turned into stringent upper limits on the annihilation cross sections of dark matter (DM) above similar to 300 GeV. Using the GALPROP code, we derive the upper limits in various propagation models and DM profiles. We show that in the "conventional" propagation model, for the q (q) over bar, b (b) over bar, and W+W- final states, the constraints could be more stringent than that derived from the recent Ferm-LAT gamma-ray data on the dwarf spheroidal satellite galaxies. Making use of the typical minimal, median, and maximal models obtained from a previous GALPROP-based global fit to the preliminary AMS-02 data, we show that the variation of the upper limits is about a factor of five. The possibility of DM contributions to the low and very high energy (p) over bar /p data is discussed.