Observation and study of a narrow state in aΣ−(1,385)K+ system

New data on the observation and study of a narrow resonance decaying intoΣ−(1,385)K+ have been obtained. The mass of the resonance is (1,956 −6 +8 ) MeV/c2, and its width is (27±15) MeV/c2. The resonance is produced in the diffraction dissociation of neutrons on quasi-free nucleons of carbon nuclei. The slope parameter of the differential cross section inP T 2 is (9.9±3.0) (GeV/c)−2. The cross section times the branching ratio is (0.22±0.04) μb per nucleon. The resonance has one of the natural spinparities: 5/2+, 7/2− and so on.