First observation of the decay K+ -> e+ nu mu+ mu-

H. Ma, R. Appel, G. S. Atoyan +23

Experiment 865 at the Brookhaven AGS has observed the decay K^+ -> e^+ nu mu^+ mu^-. The branching ratio extracted is (1.72 +/- 0.37(stat) +/- 0.17(syst) +/- 0.19(model)) x 10^{-8}…