Production of $X_b$ via $\mathrm{{\rm Y}}(5S,6S)$ radiative decays

We investigate the production of $X_b$ in the process $\mathrm{{\rm Y}}(5S,6S)\to \gamma X_b$, where $X_b$ is assumed to be a $B{\bar{B}}^{\ast }$ molecular state. Two kinds of meson loops of $B^{(\ast )}{\bar{B}}^{(\ast )}$ and $B_1^{\mathrm{\prime }}{\bar{B}}^{(\ast )}$ were considered. To explore the rescattering mechanism, we calculated the relevant branching ratios using the effective Lagrangian based on the heavy quark symmetry. The branching ratios for the $\mathrm{{\rm Y}}(5S,6S)\to \gamma X_b$ were found to be at the orders of ${10}^{-7}\sim {10}^{-6}$. Such sizeable branching ratios might be accessible at BelleII, which would provide important clues to the inner structures of the exotic state $X_b$.