Institute for High Energy Physics, P.O. 142284 Protvino, Serpukhov, Moscow Region, USSR
Abstract:
In the SKAT bubble chamber neutrino experiment production of a short-living neutral particle with mass (1.4?m?2.5) GeV/c2 and lifetime τ≈6×10?12 s has been detected. The event may be interpreted as production and decay of the heavy lepton M0→μ?+e++νe with mass (1.4?mM0?2.1) GeV/c2. It might also be the production of a charmed particle D0→e++τ?+νe (D0→e++π?+νe) with mass 1.4?mD0?2.5) GeV/c2 in a non-diagonal neutral current. The probability to interpret the event as other possible processes is very low.