Hidden strange B${}_c$-like molecular states

With the chiral unitary approach, we evaluate the hidden strange B${}_c$-like molecular states of $b\overline{c}s\overline{s}$ systems ${\overline{B}}_s{\overline{D}}_s$, ${\overline{B}}_s^{\ast }{\overline{D}}_s$, ${\overline{B}}_s{\overline{D}}_s^{\ast }$, and ${\overline{B}}_s^{\ast }{\overline{D}}_s^{\ast }$ coupled to the non-strange channels. The S-wave scattering amplitudes are calculated based on the vector meson exchange, four pseudoscalar mesons contact interactions, and four vector mesons contact interactions obtained from the extended local hidden gauge approach. We find six states below the threshold of the most relevant channel. The binding energies of these states are around 1-10 MeV and the widths are around 0.2-0.7 MeV. Our research is a supplement to the mass spectra of B${}_c$-like states, which may be useful for the experimental search in the future.