Interpretation of ${\rm Y}(11020)$ as an $S$-Wave $B_1\bar{B}$--$B_1{\bar{B}}^{\ast }$ Molecular State

Qing Lu, Cai Cheng, Yin Huang

Although heavy-quark symmetry predicts a $B_1\bar{B}$ molecular partner of the $D_1\bar{D}$ molecule, no such state has been observed. We propose that the experimentally observed $…