An Etymological Dictionary of Astronomy and Astrophysics
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فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 1 Search : secondary cosmic rays
secondary cosmic rays
  پرتوهای ِ کیهانی ِ دومان   
partowhâ-ye keyhâni-ye dovomân

Fr.: rayons cosmiques secondaires   

A burst of secondary charged and neutral particles arising when → primary cosmic rays collide with the atmospheric oxygen or nitrogen nuclei in the upper atmosphere. The collision produces mostly → pions (π), along with some → kaons (K), → antiprotons, and → antineutrons. Neutral pions very quickly decay, usually into two → gamma rays. Charged pions also decay but after a longer time. Therefore, some of the pions may collide with yet another nucleus of the air before decaying, which would be into a → muon and a → neutrino. The fragments of the incoming nucleus also interact again, also producing new particles.

secondary; → cosmic; → ray.