We have located 3886 neutrino interactions in the fiducial volume of a hybrid emulsion spectrometer installed in the Fermilab wide-band neutrino beam. A search for - decays yielded no candidate, resulting in an upper limit of 0.002 (0.073) for direct coupling of (e) to -. The (e) to limits to mass differences and mixing angles () between the neutrinos are at maximum mixing M2<0.9 (9.0) eV2, and at maximum sensitivity sin2(2)<0.004 (0.12). The direct-coupling limits are also used to show that most - decays must contain a neutral lepton other than or e.
ASJC Scopus subject areas
- Physics and Astronomy(all)