Observation of narrow baryon resonance decaying into μ-(1385) and K+

The experiment is carried out in the neutron beam of Serpukhov accelerator using the BIS-2 spectrometer. The reaction n+C → #betta#0h-h+... → p-p-h-h+... is investigated, where #betta#0 and two charged hadrons h- and h+ are produced mainly in the field of neutron beam fragmentation, the average pulse of neutrons being approximately 40 GeV/c. The charged particles have not been identified. A production of a narrow baryon resonance of approximately 1.95 GeV/c2 mass decaying into μ-(1385) and K+ is observed. The existence of the resonance has been indicated previously. The mass and width of the observed resonance equal to: M=1.955+0.02-0.01 GeV/c2 and G < or approximately 0.035 GeV/c2, respectively, have been found. The product is calculated of the resonance production cross section multiplied by the probability of the resonance decay via the channel μ-(1385)K+ σV = 0.60+-0.36 μbn/carbon nucleus. The observed resonance may be interpreted as a baryon five-quark state