The high energy window of probing dark matter with cosmic-ray antideuterium and antihelium

Abstract

Cosmic-ray (CR) anti-nuclei are often considered as important observables for dark matter (DM) indirect detections at low kinetic energies below GeV per nucleon. Since the primary CR fluxes drop quickly towards high energies, the secondary anti-nuclei in CR are expected to be significantly suppressed in high energy regions ($\gtrsim 100$ GeV per nucleon). If DM particles are heavy, the annihilation productions of DM can be highly boosted, thus the fluxes of anti-nuclei produced by DM annihilations may exceed the secondary background at high energies, which opens a high energy window for DM indirect detections. We investigate the possibility of detecting heavy DM particles which annihilate into high energy anti-nuclei. We use Monte-Carlo generators $\texttt{PYTHIA}$, $\texttt{EPOS-LHC}$ and $\texttt{DPMJET}$ and the coalescence model to simulate the production of anti-nuclei, and constrain the DM annihilation cross sections by using the AMS-02 and HAWC antiproton data and the HESS galactic center gamma-ray data. We find that the conclusion depends on the choice of DM density profiles. For the "Cored" type profile with a DM particle mass $\gtrsim 10$ TeV, the contributions from DM annihilations can exceed the secondary background in high energy regions, which opens the high energy window. While for the "Cuspy" type profile, the excess disappears.