A search for heavy neutrino decays in a neutrino beam

Abstract A search has been made for the decays of heavy (≈200–500 MeV/ c 2 ) neutrinos, ν H → νμ e, in a 23 m long detector, in the wide-band neutrino beam at the Brookhaven AGS. No significant excess of such events was found and limits are set on the neutrino mixing matrix elements, | U eH | 2 and | U μH | 2 . Results of a more general search for anomalous μe events are also reported.