Abstract
Indications for the production of a neutral excited hyperon in the reaction are observed in an experiment performed with the ANKE spectrometer at COSY-Jülich at . Two final states were investigated simultaneously, viz. and , and consistent results were obtained in spite of the quite different experimental conditions. The parameters of the hyperon state are and . The production cross section for decaying through these channels is of the order of few hundred nanobarns. Since the isospin of the has not been determined here, it could either be an observation of the , a one-star resonance of the Particle Data Group tables, or, alternatively, a hyperon. Relativistic quark models for the baryon spectrum do not predict any excited hyperon in this mass range and so the may be of exotic nature.
- Received 10 June 2005
DOI:https://doi.org/10.1103/PhysRevLett.96.012002
©2006 American Physical Society