Picture of Neutrino Interaction
Picture of neutrino interaction in the Fermilab 15-foot Bubble Chamber with heavy neonhydrogen liquid mixture taken in April, 1976. Nearly one neutrino interaction per picture is found with the current run targeting 1013 protons at 400 GeV with the wide band - two horn system. Frequently the chamber is flooded with tracks from several neutrino interactions in the same exposure.
In addition to increasing the interaction rate, the heavy neon mixture allows many of the particles from neutrino interactions to be recognized by direct inspection of the track appearance: protons, charged pions and kaons produce secondary interactions; neutral pions are evidenced by their gamma rays converting to electron pairs; muons sail right through the liquid without interacting and direct electrons or positrons from the vertex are recognized by successive kinks and associated gamma ray conversions along their tracks. A major interest in the present experiment by a Columbia University-Brookhaven Laboratory collaboration is the study of "di-lepton" events in which two muons or a muon and an electron are produced in high energy neutrino interactions.