Radiative ${\Xi }_{b}^{-}\to {\Xi }^{-}\gamma $ decay

Recently, the LHCb Collaboration performed first search for the rare radiative ${\Xi }_{b}^{-}\to {\Xi }^{-}\gamma $ decay and put an upper limit, $B\left({\Xi }_{b}^{-}\to {\Xi }^{-}\gamma \right)<1.3×{10}^{-4}$ , on its branching ratio. The measurement agrees well with existing theory prediction using SU(3) flavor symmetry method, but shows a slight tension with the previous prediction from light-cone sum rules. Inspired by this, we investigate this decay as well as other radiative decays of ${\Xi }_{b}^{0\left(-\right)}\left({\Xi }_{b}^{{}^{\prime }-}\right)$ to ${\Xi }^{0\left(-\right)}$ and ${\Sigma }^{0\left(-\right)}$ baryons using the form factors calculated from light-cone QCD sum rules in full theory. we obtain $B\left({\Xi }_{b}^{-}\to {\Xi }^{-}\gamma \right)=1.{08}_{-0.49}^{+0.63}×{10}^{-5}$ , which lies below the upper limit set by LHCb and is consistent with flavor-symmetry driven prediction. Our predictions on other channels may be checked in experiment and by other phenomenological approaches.