Limits on ν_μ(ν̅ _μ)→ν_τ(ν̅ _τ) and ν_μ(ν̅ _μ)→(ν̅ _e)ν_e Oscillations from a Precision Measurement of Neutrino-Nucleon Neutral Current Interactions

We present limits on ν_μ(ν̅ _μ)→ν_τ(ν̅ _τ) and ν_μ(ν̅ _μ)→ν_e(ν̅ _e) oscillations based on a study of inclusive νN interactions performed using the CCFR massive coarse-grained detector in the Fermilab Tevatron Quadrupole Triplet neutrino beam. The sensitivity to oscillations is from the difference in the longitudinal energy deposition pattern of ν_μN vs ν_τN or ν_eN charged-current interactions. The ν_μ energies ranged from 30 to 500 GeV with a mean of 140 GeV. The minimum and maximum ν_μ flight lengths are 0.9 and 1.4 km, respectively. For ν_μ→ν_τ oscillations, the lowest 90% confidence upper limit in sin²2α of 2.7 × 10^-3 is obtained at Δm²∼50 eV². This result is the most stringent limit to date for 25<Δm²<90 eV². For ν_μ→ν_e oscillations, the lowest 90% confidence upper limit in sin²2α of 1.9 × 10^-3 is obtained at Δm²∼350 eV². This result is the most stringent limit to date for 250<Δm²<450 eV², and also excludes at 90% confidence much of the high Δm² region favored by the recent LSND observation.