Hadronic Molecules In One-boson Exchange Model

In the past decades, a lot of new heavy-flavor hadron states have been observed in high energy physics experiments. Some of these hadron states are hard to be explained by the conventional quark model. Based on the different models, many theoretical works have devoted to the interpretation of these new hadron statets based on the different assumption of structure and theoretical approaches. At present, the widely used theoretical approaches include the QCD sum rule, the chiral perturbation theory, the chiral quark model and the one-boson exchange model. Since masses of X（4260） and X^±（4250） are only about a few tens of Me V below the first S-wave open charm DD1or**0DD threshold, we have studied the two hadron states with the assumption of hadronic molecules in one-boson exchange model at quark level.Taking into account the contribution of S-D wave mixing and retardation effects as well as the “ d function” term of one-boson exchange potential at quark level, we analyze the mass, the root of mean square radius and the probabilities of the individual channels forD₁（?）D^*₀（?）(I^G(J^PC)=0^-(1^--) and (I^G(J^PC) systems by accurately solving the corresponding coupled-channel Schr?dinger equation. The off-diagonal interaction coming from the p and η exchange compared with the diagonal interaction from the s, w and r exchange is found to play a dominant role for the formation of molecular states with(I^G(J^PC). The X（4260）could be a molecular mixture of (I^G(J^PC) with D₁（?） with D^*₀（?）; however,the interpretation of X^±（4250） as aD₁（?）D^*₀（?）molecule is disfavored.Similarly, we have investigatedX_bb andX^±_bb, which are the bottom analog of X（4260）and X^±（4250） respectively. Our results indicate that the bottom analogX_bb andX^±_bb may be a B₁（?）B^*₀（?）molecule and a B₁（?）B^*₀（?）molecule,respectively.