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


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Aguilar M., Alberti G., Alpat B., Alvino A., Ambrosi G., Andeen K., ...Daha Fazla

PHYSICAL REVIEW LETTERS, cilt.110, sa.14, 2013 (SCI-Expanded) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 110 Sayı: 14
  • Basım Tarihi: 2013
  • Doi Numarası: 10.1103/physrevlett.110.141102
  • Dergi Adı: PHYSICAL REVIEW LETTERS
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Orta Doğu Teknik Üniversitesi Adresli: Evet

Özet

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 x 10(6) positron and electron events is presented. The very accurate data show that the positron fraction is steadily increasing from 10 to similar 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. DOI: 10.1103/PhysRevLett.110.141102