Constraining the annihilation of dark matter via cosmic-ray positrons and electrons

We aim to constrain the properties of dark matter particles by several measurements of positrons and electrons from cosmic-rays. We assume that collisions of dark matter particles and dark matter anti-particles can produce positrons and electrons. The electron-positron propagation is explained by a diffusion-loss equation including loss rates, diffusion, as well as source function. We use data of cosmic-ray positrons and electrons detected by PAMELA, H.E.S.S., AMS-02 and Fermi-LAT. We compare the observational data with the electron and positron spectrum from five annihilation channels in our model to derive constraining factors regarding the cross-section of the annihilation of dark matter. The tightest constraint is provided by cosmic-ray positrons of AMS-02 for the electron channel. Dark matter with mass below a few GeV gets excluded by the cosmic-ray positrons of AMS-02 for the electron, muon and tau channels.

An interpretation of the cosmic ray e+ + e− spectrum from 10GeV to 3TeV measured by CALET on the ISS

A combined interpretation of the Calorimetric Electron Telescope (CALET) [Formula: see text] spectrum up to 3[Formula: see text]TeV and the AMS-02 positron spectrum up to 500[Formula: see text]GeV was performed and the results are discussed. To parametrize the background electron flux, we assume a smoothly broken power-law spectrum with an exponential cutoff for electrons and fit this parametrization to the measurements, with either a pulsar or 3-body decay of fermionic Dark Matter (DM) as the extra electron–positron pair source responsible for the positron excess. We found that depending on the parameters for the background, both DM decay and the pulsar model can explain the combined measurements. While the DM decay scenario is constrained by the Fermi-LAT [Formula: see text]-ray measurement, we show that 3-body decay of a 800[Formula: see text]GeV DM can be compatible with the [Formula: see text]-ray flux measurement. We discuss the capability of CALET to discern decaying DM models from a generic pulsar source scenario, based on simulated data for five years of data-taking.

Main scientific results of the DAMPE mission

DAMPE (DArk Matter Particle Explorer) is a satellite-born experiment, resulting from the collaboration of Chinese, Italian, and Swiss institutions. Since December 2015, DAMPE flights at the altitude of 500 km and collects data smoothly. The detector is made of four sub-detectors: top layers of plastic scintillators, a silicon-tungsten tracker, a BGO calorimeter (32 radiation lengths), and a bottom boron-doped scintillator to detect delayed neutrons. The main goal of the experiment is the search for indirect signals of Dark Matter in the electron and photon spectra with energies up to 10 TeV. Furthermore DAMPE studies cosmic charged and gamma radiation. The calorimeter depth and the large acceptance allow to measure cosmic ray fluxes in the range from 20 GeV up to hundreds of TeV. An overview of the latest results about light component (p+He) of charged cosmic rays, gamma astronomy and electron and positron spectrum will be presented.