Towards Understanding the Origin of Cosmic-Ray Positrons

Discussion timeslot (ZOOM-Meeting): 15. July 2021 - 18:00
ZOOM-Meeting URL: https://desy.zoom.us/j/91896950007
ZOOM-Meeting ID: 91896950007
ZOOM-Meeting Passcode: ICRC2021
Corresponding Session: https://icrc2021-venue.desy.de/channel/16-Cosmic-Ray-Antiparticles-and-Electrons-CRD-DM-GAD-MM/128
Live-Stream URL: https://icrc2021-venue.desy.de/livestream/Discussion-06/7

Abstract:
The latest precision measurements on the cosmic ray positrons flux by the Alpha Magnetic Spectrometer on the International Space Station are presented. The positron flux exhibits complex energy dependence. Its distinctive properties are (a) a significant excess starting from 25 GeV compared to the lower-energy, power-law trend, (b) a sharp drop-off above 284 GeV, (c) in the entire energy range the positron flux is well described by the sum of a term associated with the positrons produced in the collision of cosmic rays, which dominates at low energies, and a new source term of positrons, which dominates at high energies, and (d) a finite energy cutoff of the source term at 810 GeV is established with a significance of more than 4σ. These experimental data on cosmic ray positrons show that, at high energies, they predominantly originate either from dark matter annihilation or from new astrophysical sources.'

Authors: Zhili Weng | For the AMS Collaboration
Collaboration: AMS

Indico-ID: 1024
Proceeding URL: https://pos.sissa.it/395/122