| The Fermilab experiment E872 (DONUT) was designed to make the first observation of the tau neutrino charged-current interaction. Using a hybrid emulsion-spectrometer detector, the tau lepton was identified by its single-prong or trident decay. Six interactions were observed, of which five were in the deep inelastic scattering region. These five interaction were used to measure the charged-current cross section of the tau neutrino. To minimize uncertainties, the tau neutrino cross section was measured relative to the electron neutrino cross section. The result sconstn tNsconst neN=0.77+/-0.39 is consistent with 1.0, which is predicted by lepton universality. The tau neutrino cross section was also measured for 115 GeV neutrinos, which was the average energy of the interacted tau neutrinos. The result sexpnt N=45+/-21x10-38 cm2 is consistent with the standard model prediction calculated in this thesis, sSMnt N=48+/-5x10-38 cm2. |
