Exotic hadrons as heavy hadronic molecules and their partners

In 2022, the doubly charmed tetraquark $T_{cc}\sim cc\bar{u}\bar{d}$ was reported by LHCb. Since the exotic state is located just below the $DD^\ast$ threshold, it is considered to be a $DD^\ast$ molecule. In this talk, we study the $D^{(\ast)}D^{(\ast)}$ coupled channel systems in the meson exchange potential model. By tuning the cutoff parameter, the model explains $T_{cc}$ as a $D^{(\ast)}D^{(\ast)}$ molecule with $I(J^P)=0(1^+)$. Furthermore, by replacing $D$ with $\Xi_{cc}$ respecting the superflavor symmetry, new pentaquark $\bar{D}^{(\ast)}\Xi_{cc}^{(\ast)}$ is also investigated. We find a bound state for $I(J^P)=0(1/2^-)$ below the $\bar{D}\Xi_{cc}$ threshold. To form these bound states, the $\sigma$ exchange potential plays a dominant role to produce an attraction. In addition, the coupled-channel effect induced by the $\pi$ and $\rho$ exchange potentials support to generate an attraction.