Results of search via the reaction at J-PARC

Yamaga, Takumi*; Hashimoto, Tadashi   ; Tanida, Kiyoshi   ; 66 of others*

There is a long-standing argument of the existence of kaonic nucleus, which is a bound state of anti-kaon and nucleus. Theoretically, its existence is strongly supported, however its binding energy and width have not been established yet. It is strongly desired to have an experiment to investigate the simplest kaonic nucleus, so-called bound state. We performed an experiment to search for via the in-flight reaction at J-PARC. By studying invariant mass spectrum in the final state and its dependence on momentum transfer of , we observed a resonant state located below . The mass and width of this resonant state are MeV/, and MeV, respectively, which can be naturally interpreted as a theoretically predicted bound state.