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

2013/04/03 by M. Aguilar, G. Alberti, B. Alpat +97 · 1,062 citations
Physics and Astronomy · #Anisotropy #Antimatter #Astrophysics and Cosmic Phenomena #Atomic physics #Cosmic ray #Dark Matter and Cosmic Phenomena #Electron #International Space Station #Materials science #Nuclear physics #Observable #Optics #PAMELA detector #Particle physics theoretical and experimental studies #Physics #Positron #Range (aeronautics) #Spectrometer #Ultra-high-energy cosmic ray

paper · pdf · doi:10.1103/physrevlett.110.141102

published in Physical Review Letters 110(14), 141102 (American Physical Society)

openalex publication_date 2013/04/03 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05

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 × 10(6) 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.

Citations

• Pulsars as the sources of high energy cosmic ray positrons
• New Measurement of the Cosmic-Ray Positron Fraction from 5 to 15 GeV
• Geant4 developments and applications
• Astrophysical models for the origin of the positron “excess”
• The role of antimatter searches in the hunt for supersymmetric dark matter
• Boosted decision trees as an alternative to artificial neural networks for particle identification
• The AMS-02 Anticoincidence Counter
• Performance of the AMS-02 transition radiation detector
• Measurement of the Positron to Electron Ratio in the Cosmic Rays above 5 GeV
• An anomalous positron abundance in cosmic rays with energies 1.5–100 GeV
• The Alpha Magnetic Spectrometer (AMS) on the International Space Station: Part I – results from the test flight on the space shuttle

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• (In)Direct detection of boosted dark matter
• Experimental Summary: Very High Energy Cosmic Rays and their Interactions
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• The DArk Matter Particle Explorer mission
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• Propagation in 3D spiral-arm cosmic-ray source distribution models and secondary particle production using Picard
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• Gamma-Ray Polarimetry: A New Window for the Nonthermal Universe
• Constraints on dark photon from neutrino-electron scattering experiments
• Origin of hardening in spectra of cosmic ray nuclei at a few hundred GeV using AMS-02 data *
• Sensitivity projections for dark matter searches with the Fermi large area telescope
• Minimal decaying Dark Matter and the LHC
• Cosmic Ray Origins: An Introduction
• Effective field theory interpretation of searches for dark matter annihilation in the Sun with the IceCube Neutrino Observatory
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• Excesses of cosmic ray spectra from a single nearby source
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• ORIGIN OF THE COSMIC RAY POSITRONS OBSERVED NEAR EARTH: MESON DECAY OR DARK MATTER DECAY?
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• Antimatter [wikipedia]
• Positron [wikipedia]

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