Evidence for a narrow resonance at 1530MeV/c2 in the K0p-system of the reaction pp→Σ+K0p from the COSY-TOF experiment

M. Abdel-Bary, S. Abdel-Samad, K.-Th. Brinkmann, H. Clement, E. Doroshkevich, M. Drochner, S. Dshemuchadse, A. Erhardt, W. Eyrich, D. Filges, A. Filippi, H. Freiesleben (+38 others)
2004 Physics Letters B  
The hadronic reaction pp --> Sigma+ K0 p was measured exclusively at a beam momentum of 2.95 GeV/c using the TOF detector at the COSY storage ring. A narrow peak was observed in the invariant mass spectrum of the K0 p subsystem at 1530 +- 5 MeV/c2 with a significance of 4 - 6 standard deviations, depending on background assumptions. The upper limit of 18 +- 4 MeV/c2 (FWHM) for its width is given by the experimental resolution. The corresponding total cross section is estimated to be about 0.4
more » ... 0.1(stat) +- 0.1(syst) microbarn. Since a resonance in this subsystem must have strangeness S = + 1 we claim it to be the Theta+ state for which very recently evidence was found in various experiments.
doi:10.1016/j.physletb.2004.05.067 fatcat:ujoee4kx7bfspdnlplaqycvwl4