Interpretation of ϒ ( 11020 ) as an S -wave B 1 B ¯ − B 1 B ¯ * molecular state

Although heavy-quark symmetry implies a B 1 B ¯ molecular partner of the D 1 D ¯ molecule, no such state has been observed experimentally to date. In this work, we propose that the experimentally observed ϒ ( 11020 ) may be a candidate for such a molecular state, although it may also contain a B 1 B ¯ * component. To explore whether the ϒ ( 11020 ) can be interpreted as an S -wave B 1 B ¯ – B 1 B ¯ * molecule, we calculate its strong decay widths within this molecular scenario using the compositeness condition and effective Lagrangians. The coupling of the ϒ ( 11020 ) to its constituents B 1 and B ¯ ( * ) is determined by fitting the available experimental data on ϒ ( 11020 ) → e + e − and ϒ ( 11020 ) → χ b J π π π decays. With the extracted coupling, we compute the partial decay widths of the ϒ ( 11020 ) into B ( s ) ( * ) B ¯ ( s ) ( * ) , π π ϒ ( n S ) , π π h b ( n P ) , and π π π χ b 1