Exploratory study of possible resonances in the heavy meson - heavy baryon coupled-channel interactions

We use a unitary coupled-channel model to study the $\bar{D} \Lambda_c - \bar{D} \Sigma_c$ interactions. In our calculation, SU(3) flavor symmetry is applied to determine the coupling constants. Several resonant and bound states with different spin and parity are dynamically generated in the mass range of the recently observed pentaquarks. The approach is also extended to the hidden beauty sector to study the $B{\mathrm{\Lambda }}_b-B{\mathrm{\Sigma }}_b$ interactions. As the $b$-quark mass is heavier than the $c$-quark mass, there are more resonances observed for $B{\mathrm{\Lambda }}_b-B{\mathrm{\Sigma }}_b$ interactions and they are more tightly bound.