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

Abstract

AbstractRecently, the LHCb Collaboration performed first search for the rare radiative $$\Xi _{b}^{-}\rightarrow \Xi ^{-}\gamma $$ Ξ b - → Ξ - γ decay and put an upper limit, $$\mathcal{B}(\Xi _{b}^{-}\rightarrow \Xi ^{-}\gamma ) < 1.3 \times 10^{-4}$$ B ( Ξ b - → Ξ - γ ) < 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 $$\Xi _b^{0(-)}(\Xi ^{'-}_{b})$$ Ξ b 0 ( - ) ( Ξ b ′ - ) to $$\Xi ^{0(-)}$$ Ξ 0 ( - ) and $$\Sigma ^{0(-)}$$ Σ 0 ( - ) baryons using the form factors calculated from light-cone QCD sum rules in full theory. we obtain $$ \mathcal{B}(\Xi _{b}^{-}\rightarrow \Xi ^{-}\gamma )=1.08^{+0.63}_{-0.49} \times 10^{-5} $$ B ( Ξ b - → Ξ - γ ) = 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.