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

Abstract

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.