Molecular states from D()D()B()B() and D()D()B()B interactions

In this work, we preform a systematic investigation about hidden heavy and doubly heavy molecular states from the D()D()/B()B() and D()D()/B()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 Upsilon exchange. Possible bound states from the interactions considered are searched for as the pole of scattering amplitude. The results suggest that experimentally observed states, Zc(3900), Zc(4020), Zb(10610), and Zb(10650), can be related to the DD, DD, BB, and BB interactions with quantum numbers IG(JP)=1+(1+), respectively. The DD 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 DD and BB molecular states with 0(0+) are predicted. The possible DD 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/BB interaction while a bound state is found with 0(1+) from DD/BB interaction. The DD/BB interaction produces three molecular states with 0(1+), 0(2+) and 1(2+).