Search for Neutrino Oscillations at Fermilab

Abstract

In this brief presentation I will discuss the results to date of the search for neutrino oscillations by the BNL-Columbia collaboration at Fermilab. The experiment was particularly sensitive to the transformation ν _µ →ν _e and ν _µ → ν _τ. The technique utilized the FNAL 15’ cryogenic bubble chamber filled with a hydrogen-neon mixture. The pertinent properties of this detector are the weight of 30 tons, radiation length l _R = 40cm and interaction length l _I = 125cm. One therefore has reasonable event rate, electron and hadron detection. 400 GeV protons were utilized in a standard, broad band, horn focused, neutrino beam to produce −1 event per picture. The distance from the point of creation of neutrinos to their detection is 1.2km and the average energy of the neutrinos is 25 GeV, with a spectrum that ranges from 5 GeV to 150 GeV. The results I will report on involve an accumulation of 100,000 charge current events ν _µ + N→ µ + anything, and 800 observed events including a single electron (e). For the benefit of those individuals with a short attention span, I will now give the results.