High Statistics Measurement of the Positron Fraction in Primary Cosmic Rays with the Alpha Magnetic Spectrometer on the International Space Station

Sami Caroff (for the AMS-02 collaboration)
(Submitted on 30 Dec 2016)

A precision measurement by AMS-02 of the positron fraction in primary cosmic rays is presented on this proceeding. Over the last two decades, there has been a strong interest in the cosmic ray positron fraction which exhibit an excess of high energy positrons whose origin is still highly uncertain. The Alpha Magnetic Spectrometer (AMS-02) is a general purpose high-energy particle physics detector operational on the International Space Station since May 2011. During its unique long duration mission AMS-02 is collecting large amount of data to study the behavior of cosmic ray electrons and positrons with unprecedented precision. This measurement shows that the positron fraction exhibit a rapid decrease from 1 to 8 GeV followed by a steady increase. We show that above 275 GeV the positron fraction no longer exhibits an increase with energy.

Comments:    XXV ECRS 2016 Proceedings – eConf C16-09-04.3
Subjects:    High Energy Astrophysical Phenomena (astro-ph.HE)
Cite as:    arXiv:1612.09579 [astro-ph.HE] (or arXiv:1612.09579v1 [astro-ph.HE] for this version)
Submission history
From: Sami Caroff
[v1] Fri, 30 Dec 2016 20:04:45 GMT (263kb,D)
https://arxiv.org/abs/1612.09579