Molecular states from D^{(*)}{bar{D}}^{(*)}/B^{(*)}{bar{B}}^{(*)} and D^{(*)}D^{(*)}/{bar{B}}^{(*)}{bar{B}}^{(*)} interactions

Abstract

In this work, we preform a systematic investigation about hidden heavy and doubly heavy molecular states from the D^{(*)}{bar{D}}^{(*)}/B^{(*)}{bar{B}}^{(*)} and D^{(*)}D^{(*)}/{bar{B}}^{(*)}{bar{B}}^{(*)} interactions in the quasipotential Bethe–Salpeter equation (qBSE) approach. With the help of Lagrangians with heavy quark and chiral symmetries, interaction potentials are constructed within the one-boson-exchange model in which we include the pi , eta , rho , omega and sigma exchanges, as well as J/psi or varUpsilon exchange. Possible bound states from the interactions considered are searched for as the pole of scattering amplitude. The results suggest that experimentally observed states, Z_c(3900), Z_c(4020), Z_b(10610), and Z_b(10650), can be related to the D{bar{D}}^{*}, D^*{bar{D}}^{*}, B{bar{B}}^{*}, and B^*{bar{B}}^{*} interactions with quantum numbers I^G(J^P)=1^+(1^{+}), respectively. The D{bar{D}}^{*} interaction is also attractive enough to produce a pole with 0^+(0^+) which is related to the X(3872). Within the same theoretical frame, the existence of D{bar{D}} and B{bar{B}} molecular states with 0(0^+) are predicted. The possible D^*{bar{D}}^* molecular states with 0(0^+, 1^+, 2^+) and 1(0^+) and their bottom partners are also suggested by the calculation. In the doubly heavy sector, no bound state is produced from the DD/{bar{B}}{bar{B}} interaction while a bound state is found with 0(1^+) from DD^*/{bar{B}}{bar{B}}^* interaction. The D^*D^*/{bar{B}}^*{bar{B}}^* interaction produces three molecular states with 0(1^+), 0(2^+) and 1(2^+).