Search for {\Theta^+} in KLp \to K+n reaction in KLF at JLab

The possibility of the existence of multiquark hadrons made of 4-quark for mesons and 5-quark for baryons was predicted by Gell-Mann in Ref. [1]. The renewed interest for the search of exotic pentaquark states was initiated by the paper by Diakonov, Petrov, and Polyakov in Ref. [2]. The 2003 experimental reports on the observation of {\Theta^+} pentaquark with a uudd{\bar s} quark content created a big excitement and many following experiments have reported its observation [3]. After high-statistics experiments at JLab, which did not confirm previous claims by the CLAS collaboration, the community concluded that the {\Theta^+} pentaquark either does not exist at all or has an extremely small cross section, making it currently unobserved. There were different review papers on this subject, either questioning the existence of the {\Theta^+} or attempting to explain the reasons why reaching a conclusion based on production experiments is challenging [4]. To address the challenge of minimal 3-body final states, a formation experiment with a projectile kaon beam is proposed. Below, we discuss how the {\Theta^+} could be observed in the KLp \to {\Theta^+} \to {K^+}n reaction in the KLF experiment at JLab [5].