First Result from the Alpha Magnetic Spectrometer on the International Space Station: Precision Measurement of the Positron Fraction in Primary Cosmic Rays of 0.5–350 GeV

AMS Collaboration

doi:10.1103/PhysRevLett.110.141102

Scientific article

English

First Result from the Alpha Magnetic Spectrometer on the International Space Station: Precision Measurement of the Positron Fraction in Primary Cosmic Rays of 0.5–350 GeV

Contributors

AMS Collaboration

Collaborators

Azzarello, Philipp; Bourquin, Maurice; Cadoux, Franck; Habiby Alaoui, Marion; Leluc, Catherine; Masciocchi, Florian; Paniccia, Mercedes

; Perrin, Eric; Pohl, Martin; Rapin, Divic Jean; Saouter, Pierre

Published in

Physical review letters, vol. 110, no. 14, 141102

Publication date

2013

Abstract

A precision measurement by the Alpha Magnetic Spectrometer on the International Space Station of the positron fraction in primary cosmic rays in the energy range from 0.5 to 350 GeV based on 6.8×106 positron and electron events is presented. The very accurate data show that the positron fraction is steadily increasing from 10 to ∼250 GeV, but, from 20 to 250 GeV, the slope decreases by an order of magnitude. The positron fraction spectrum shows no fine structure, and the positron to electron ratio shows no observable anisotropy. Together, these features show the existence of new physical phenomena.

UNIGE affiliation entities

Faculté des sciences / Section de physique / Département de physique nucléaire et corpusculaire

Citation (ISO format)

AMS Collaboration. First Result from the Alpha Magnetic Spectrometer on the International Space Station: Precision Measurement of the Positron Fraction in Primary Cosmic Rays of 0.5–350 GeV. In: Physical review letters, 2013, vol. 110, n° 14, p. 141102. doi: 10.1103/PhysRevLett.110.141102

Article (Published version)

Identifiers

PID : unige:40557
DOI : 10.1103/PhysRevLett.110.141102

Additional URL for this publication

http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.110.141102

Journal ISSN

0031-9007

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Creation

26/09/2014 15:31:00

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26/09/2014 15:31:00

Update

13/10/2025 22:22:13

Status update

14/03/2023 21:48:12

Last indexation

10/11/2026 17:09:41

First Result from the Alpha Magnetic Spectrometer on the International Space Station: Precision Measurement of the Positron Fraction in Primary Cosmic Rays of 0.5–350 GeV

Contributors

Collaborators

Published in

Publication date

Abstract

UNIGE affiliation entities

Citation (ISO format)

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Additional URL for this publication

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First validation

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