2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/177483Experiment 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} where the third term in the error results from the use of a model to extrapolate into a kinematic region dominated by background.4 pages, 6 figures, Revtex4. Correction to figure and minor text changesHigh Energy Physics - Experimenttext