; Zhang, Zong-Ye] Chinese Acad Sci, Inst High Energy Phys, Beijing 100049, Peoples R China
; [Zhang, Zong-Ye] Chinese Acad Sci, Theoret Phys Ctr Sci Facil, Beijing 100049, Peoples R China
We investigated systematically whether the S-wave (Qq) meson and the (Qq) meson may form S-wave bound states in a chiral SU(3) quark model by solving the resonating group method equation. Here Q=c or b and q=u,d, or s. Our preliminary calculation disfavors the existence of I=12(Ql)-(Qs) molecules (l=u,d) but favors the existence of isoscalar BB, (BB*)-B-*(J=2), and BB*(C=+) molecules. The existence of isovector (charm-anticharm) and (charm-bottom) molecules is also disfavored. Therefore the resonance-like structure Z(+)(4051) is unlikely to be an S-wave (DD*)-D-* molecule.