Astrophysical Background and Dark Matter Implication Based on Latest AMS-02 Data

The cosmic-ray (CR) positrons and antiprotons are often regarded as the collision products of CR nucleons with the interstellar medium. However, the predicted fluxes of CR positrons and antiprotons by the conventional models are not consistent with the experimental data from PAMELA, Fermi-LAT, AMS-02, etc. In this work, we choose the latest AMS-02 data to analyze the astrophysical background of CR positrons and antiprotons. QGSJET-II-04 is chosen as the hadronic interaction model. The GALPROP package is used to solve the propagation equation numerically. The results show that the predicted flux of CR positrons at low energies is consistent with AMS-02 data in the reacceleration and convection-diffusion (DCR) model. In the DCR model and the hadronic interaction model, QGSJET-II-04, the excess of CR antiprotons at low energies is excluded. The dark matter interpretation of the positron excess is analyzed with the total fluxes of CR electrons and positrons from AMS-02. The predicted best-fit mass of dark matter ranges from 400 GeV to 4 TeV. Moreover, in the above models the predicted flux of CR protons is completely consistent with AMS-02 data, which matches the hardening feature above 330 GeV.