Search for the Decay K+ -> pi+ pi0 nu nubar
  The first search for the decay K^+ -> pi^+ pi^0 nu nubar has been performed with the E787 detector at BNL. Based on zero events observed in the kinematical search region defined by 90 MeV/c < P_{pi^+} < 188 MeV/c and 135 MeV < E_{pi^0} < 180 MeV, an upper limit B(K^+ -> pi^+ pi^0 nu nubar) < 4.3 x 10^{-5} at 90% confidence level is established. 
E787: S. Adler, M. Aoki, M. Ardebili, M.S. Atiya, P.C. Bergbusch, E.W.   Blackmore, D.A. Bryman, I-H. Chiang, M.R. Convery, ...