The Mass spectrum of pentaquarks in hadron dynamics

Yamaguchi, Yasuhiro   

Recently exotic hadrons including a component have been reported in experimental researches. The exotic states cannot be explained by the ordinary hadron picture, namely a baryon as a three-quark state, and a meson as a quark-antiquark state, while a multiquark component would be dominated in their structure. We investigate the pentaquarks reported by LHCb as a hadronic molecule coupling to a compact core. The coupling to the core plays an short-range interaction ( potential) generating an attraction. In addition, the one pion exchange potential (OPEP) as a long-range interaction is introduced. Our model can consistently explain the masses and widths of the states reported by LHCb in 2019. The role of the interactions employed is investigated, and we find that the structure of the energy level is determined by the potential, while the decay width by the tensor term of the OPEP.