A search for very short-lived particles produced by neutrinos in nuclear emulsion

A sample of 22 neutrino-induced events in nuclear emulsion have been measured and analyzed with a X2 method to search for secondary vertices, i.e. possible decays of short-lived particles. Production and decay vertices as close as 0.5 μm can, under favourable conditions, be resolved. No candidates for such very short paths were found. We have, however, found a track with a kink which is consistent with one prong decay. (authors)