Systematics of the heavy flavor hadronic molecules

Abstract

Abstract With a quark level interaction, we give a unified description of the loosely bound molecular systems composed of the heavy flavor hadrons $$({\bar{D}},{\bar{D}}^*)$$ ( D ¯ , D ¯ ∗ ) , $$(\Lambda _c, \Sigma _c, \Sigma _c^*)$$ ( Λ c , Σ c , Σ c ∗ ) , and $$(\Xi _c, \Xi _c^\prime ,\Xi _c^*)$$ ( Ξ c , Ξ c ′ , Ξ c ∗ ) . Using the $$P_c$$ P c states as inputs to fix the interaction strength of light quark-quark pairs, we reproduce the observed $$P_{cs}$$ P cs and $$T_{cc}^+$$ T cc + states and predict another narrow $$T_{cc}^{\prime +}$$ T cc ′ + state with quantum numbers $$[D^*D^*]_{J=1}^{I=0}$$ [ D ∗ D ∗ ] J = 1 I = 0 . If we require a satisfactory description of the $$T_{cc}^+$$ T cc + and $$P_c$$ P c states simultaneously, our framework prefers the assignments of the $$P_{c}(4440)$$ P c ( 4440 ) and $$P_{c}(4457)$$ P c ( 4457 ) as the $$[\Sigma _c{\bar{D}}^*]_{J=1/2}^{I=1/2}$$ [ Σ c D ¯ ∗ ] J = 1 / 2 I = 1 / 2 and $$[\Sigma _c{\bar{D}}^*]_{J=3/2}^{I=1/2}$$ [ Σ c D ¯ ∗ ] J = 3 / 2 I = 1 / 2 states, respectively. We propose the isospin criterion to explain naturally why the experimentally observed $$T_{cc}$$ T cc , $$P_c$$ P c , and $$P_{cs}$$ P cs molecular candidates prefer the lowest isospin numbers. We also predict the loosely bound states for the bottom di-hadrons.