We present the results of a search for ν µ → ν e oscillations in the NOMAD experiment at CERN. The experiment looked for the appearance of ν e in a predominantly ν µ wide-band neutrino beam at the CERN SPS. No evidence for oscillations was found. The 90% confidence limits obtained are m 2 < 0.4 eV 2 for maximal mixing and sin 2 (2θ) < 1.4 × 10 −3 for large m 2. This result excludes the LSND allowed region of oscillation parameters with m 2 10 eV 2 .

With additional data and improved algorithms, we have enhanced the sensitivity of our appearance search for ν µ → ν τ oscillations in the NOMAD detector in the CERN-SPS wide-band neutrino beam. The search uses kinematic criteria to identify ν τ charged current interactions followed by decay of the τ − to one of several decay modes. Our "blind" analyses of deep-inelastic scattering data taken in 1996 and 1997, combined with consistent reanalyses of previously reported 1995 data, yield no oscillation signal. For the two-family oscillation scenario, we present the contour outlining a 90% C.L. confidence region in the sin 2 2θ µτ − ∆m 2 plane. At large ∆m 2 , the confidence region includes sin 2 2θ µτ < 1.2 × 10 −3 (a limit 3.5 times more stringent than in our previous publication), while at sin 2 2θ µτ = 1, the confidence region includes ∆m 2 < 1.2 eV 2 /c 4 .

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