Exotic Baryons from a Heavy Meson and a Nucleon

Abstract

Hadronic molecules have been considered to be one of the candidate of exotic hadron structures near the threshold. In the heavy quark sector, new symmetry, called the heavy quark symmetry, plays an important role to form the molecules. This symmetry has an essential role which is to enhance the one pion exchange potential arising through the mixing of heavy pseudoscalar and heavy vector mesons. In this study, we investigate new hadronic molecule formed by the heavy meson $$P^{(*)}=\bar{D}^{(*)},B^{(*)}$$ and a nucleon N, being $$P^{(*)}N$$ and $$P^{(*)}NN$$ few-body states. As the interaction between P and N, the $$\pi $$ exchange and vector meson ( $$\rho $$ and $$\omega $$ ) exchanges are considered. By solving the coupled-channel schrödinger equations for PN(N) and $$P^{(*)}N(N)$$ , we predict the bound and resonant states in the charm and bottom sectors. In the bound and resonant states, the $$PN-P^*N$$ mixing effect is important, where the tensor force of the one pion exchange potential generates the strong attraction.