Measurement of separate electron and positron spectra from 10 GeV to 20GeV with the geomagnetic field on DAMPE

TL;DR

This paper reports on DAMPE's measurement of separate cosmic-ray electron and positron spectra between 10 and 20 GeV using Earth's magnetic field, providing data consistent with AMS-02 and PAMELA, and highlighting systematic differences with Fermi-LAT.

Contribution

It introduces a novel method to distinguish electrons and positrons using Earth's magnetic field without an onboard magnet in DAMPE.

Findings

Results align with AMS-02 and PAMELA measurements.

Fermi-LAT results are systematically higher.

Energy range limited by DAMPE's orientation.

Abstract

The cosmic-ray (CR) electrons and positrons in space are of great significance for studying the origin and propagation of cosmic-rays. The satellite-borne experiment DArk Matter Particle Explorer (DAMPE) has been used to measure the separate electron and positron spectra, as well as the positron fraction. In this work, the Earth's magnetic field is used to distinguish CR electrons and positrons, as the DAMPE detector does not carry an onboard magnet. The energy range for the measurements is from 10 to 20 GeV, being currently limited at high energy by the zenith pointing orientation of DAMPE. The results are consistent with previous measurements based on the magnetic spectrometer by AMS-02 and PAMELA, while the results of Fermi-LAT seem then to be systematically shifted to larger values.