Evidence for the Strangeness S=+1 Pentaquark from LEPS and CLAS Experiments

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There are now several experimental collaborations that have seen evidence for a narrow state in the mass spectrum of the (nK+) system. Two of these experiments, from the LEPS collaboration in Japan and the CLAS collaboration in the USA, are described briefly. Both use similar photoproduction reactions with a K+K- pair in the final state. In addition, data from the CLAS collaboration for the γp → Kₛ K+ n reaction are presented for the first time, which has no prominant peak in the (nK+) mass spectrum when the Kₛ angle is limited to forward angles.