Search for mu+to e+e+e-decay

Abstract
A search with the large solid angle spectrometer (ARES) for the lepton-number-nonconserving decay mu + to e+e+e- has been carried out. Cylindrical multiwire proportional chambers and cylindrical scintillation hodoscopes were used. The upper limit for the branching ratio Gamma ( mu + to e+e+e-)/ Gamma ( mu + to e+ nu e nu mu )-11 (90% C.L.) has been derived.