Streamer chamber photo of an event at the Low Energy Antiproton Ring (LEAR) at CERN, the European particle physics laboratory outside Geneva. A 600 Me

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Streamer chamber photo of an event at the Low Energy Antiproton Ring (LEAR) at CERN, the European particle physics laboratory outside Geneva. A 600 MeV antiproton enters at the bottom of the picture & annihilates with a proton in a nucleus of the helium gas that fills the chamber. The collision produces a proton, a positive & negative pion, & a neutral kaon. Being neutral, the kaon leaves no track, but betrays its presence when it decays to a positive & negative pion pair. Reactions of this kind occurred in the early universe, at a time when lightweight nuclei such as helium were beginning to form. The distance between the crosses is 28 cm.

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Size: 3536px × 3046px
Photo credit: © PROF. G PIRAGINO/SCIENCE PHOTO LIBRARY / Alamy / Afripics
License: Licensed
Model Released: No

Keywords: anti-proton, antiproton, cern, chamber, helium-4, image, imagery, kaon, lear, particle, photo, photograph, physics, pion, streamer