An Improved Limit on the Rate Of Decay K+ -> pi+ mu+ e-
  The experiment E865 at BNL places an upper limit on the branching ratio for the decay K+ -> pi+ mu+ e- of 3.9x10^-11 (90% C.L.). Along with with other results this yields a combined upper limit on this branching ratio of 2.8x10^-11. A new upper limit on the branching ratio for pi0 -> mu+ e- of 3.8x10^-10 (90% C.L.) is also established. The experiment and analysis are described. 
R.Appel, G.S.Atoyan, B.Bassalleck, D.R.Bergman, D.N.Brown, N.Cheung,   S.Dhawan, H.Do, J.Egger, S.Eilerts, C.Felder, H.Fisch...