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
Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas · European Organization for Nuclear Research · +59 more institutions
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.
Citation impact
- FWCI
- 246.82
- Percentile
- 100%
- References
- 47
Authors
348- MAM. AguilarCorresponding
Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas, European Organization for Nuclear Research
- GAG. Alberti
University of Perugia, Istituto Nazionale di Fisica Nucleare, Sezione di Perugia
- BAB. Alpat
Istituto Nazionale di Fisica Nucleare, Sezione di Perugia
- AAA. Alvino
University of Perugia, Istituto Nazionale di Fisica Nucleare, Sezione di Perugia
- GAG. Ambrosi
Istituto Nazionale di Fisica Nucleare, Sezione di Perugia
Topics & keywords
- Positron
- Physics
- Cosmic ray
- Nuclear physics
- Electron
- Spectrometer
- International Space Station
- PAMELA detector
- Affordable and clean energy
Funding
- NSNational Science Foundation
- UDU.S. Department of Energy
- NANational Aeronautics and Space Administration
- CCERN
- SStrong
- ANAgence Nationale de la Recherche
- SNSchweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung
- NNNational Natural Science Foundation of ChinaAward: IN2P3
- NSNational Science Council
- ASAcademia Sinica
- CPCentro para el Desarrollo Tecnológico Industrial
- CNCentre National d’Etudes SpatialesAward: IN2P3
- CNCentre National de la Recherche Scientifique
- SAScience and Technology Facilities CouncilAward: ST/F007027/1
- SDSecretaría de Estado de Investigación, Desarrollo e Innovación
- CDCentro de Investigaciones Energéticas, Medioambientales y Tecnológicas
- INInstitut National de Physique Nucléaire et de Physique des Particules