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arXiv · hep-ex/0301020

Evidence for Narrow S=+1 Baryon Resonance in Photo-production from Neutron

LEPS Collaboration·T. Nakano
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Abstract

The gamma n -> K+ K- n reaction on 12C has been studied by measuring both K+ and K- at forward angles. A sharp baryon resonance peak was observed at 1.54 +- 0.01 GeV with a width smaller than 25 MeV and a Gaussian significance of 4.6 sigma. The strangeness quantum number (S) of the baryon resonance is +1. It can be interpreted as a molecular meson-baryon resonance or alternatively as an exotic 5-quark state (uudd{s_bar}) that decays into a K+ and a neutron. The resonance is consistent with the lowest member of an anti-decuplet of baryons predicted by the chiral soliton model.

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LEPS Collaboration, T. Nakano. 2003-07-08. Evidence for Narrow S=+1 Baryon Resonance in Photo-production from Neutron. https://doi.org/10.1103/physrevlett.91.012002

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