PoS - Proceedings of Science
Volume 358 - 36th International Cosmic Ray Conference (ICRC2019) - CRD - Cosmic Ray Direct
Towards Understanding the Origin of Cosmic-Ray Positrons
Z. Weng* On behalf of the AMS Collaboration
*corresponding author
Full text: pdf
Pre-published on: July 22, 2019
Published on:
Abstract
Precision measurements of cosmic ray positrons by the Alpha Magnetic Spectrometer on the International Space Station are presented up to 1 TeV based on 1.9 million positrons.
The positron flux exhibits a significant excess starting from $25.2 \pm 1.8$ GeV followed by a sharp drop-off above $284^{+91}_{-64}$ GeV.
In the entire energy range the positron flux is well described by the sum of a diffuse term
associated with low energy secondary positrons produced in the collision of cosmic rays, and a new source term of high energy positrons with a finite energy cutoff. The finite cutoff energy of the source term, $E_s$, is established with a significance of more than $4 \sigma$, and it's value is determined to be $E_s = 810^{+310}_{-180}$ GeV.
These experimental data on cosmic ray positrons show that, at high energies, they predominantly originate either from dark matter collisions or from new astrophysical sources.
How to cite

Metadata are provided both in "article" format (very similar to INSPIRE) as this helps creating very compact bibliographies which can be beneficial to authors and readers, and in "proceeding" format which is more detailed and complete.

Open Access
Creative Commons LicenseCopyright owned by the author(s) under the term of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.