Bubble chamber photo of sigma particle decay. The sigma lives too briefly to be seen; its presence is deduced from other particles. A neutrino enters unseen at bottom & collides with a proton in the bubble chamber liquid,producing the sigma & a negative muon. The sigma decays to 1 negative & 3 positive pions,& a neutral lambda which leaves no track but betrays itself when it decays at lower centre (within the loop) to a proton & a negative pion. Negative particles curl anticlockwise,positive ones clockwise in the magnetic field. One positive pion is of lower energy & forms the loop; the muon & one of the pions knock out atomic electrons which produce the two spiral tracks | |
Licence : | Droits gérés |
Crédit: | Science Photo Library / Brookhaven National Laboratory |
Taille de l’image : | 2440 px × 3553 px |
Model Release : | Non requis |
Property Release : | Non requis |
Restrictions : |
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