a Search for Antineutrino Oscillations in a Neon/hydrogen Bubble Chamber.

The FNAL 15' bubble chamber was exposed to a wide -band. (nu)(,(mu)) beam with a slight contamination of (nu)(,e), (nu)(,(mu)) and (nu)(,e). The observed ratio of single-e('+) events to single -(mu)('+) events was compared with a Monte-Carlo prediction of the expected (nu)(,e)/(nu)(,(mu)) charged-current (CC) event ratio due to oscillations, taking into account the expected (nu)(,e) contamination. In the standard two-neutrino oscillation model, the following 90% C.L. limits were found for (nu)(,(mu)) (<--->) (nu)(,e) oscillations: (DELTA)m('2) < 0.7 eV('2) (for sin('2) 2(alpha) = l) and sin('2) 2(alpha) < 0.018 (for (DELTA)m('2)(--->)(INFIN)). The kinematic characteristics of the e('+) events were compared with Monte-Carlo predictions for (nu)(,e) CC interactions and for (nu)(,(tau)) CC interactions followed by the decay (tau)('+) (--->) e('+)(nu)(,e)(nu)(,(tau)), to set similar limits on (nu)(,(mu)) (<--->) (nu)(,(tau)) oscillations: (DELTA)m('2) < 2.2 eV('2) and sin('2) 2(alpha) < 0.048.