Radiative Ξb- → Ξ-γ decay

Recently, the LHCb Collaboration performed first search for the rare radiative Xi(-)(b) -> Xi(-)(gamma) decay and put an upper limit, B(Xi(-)(b) -> Xi(-)(gamma)) < 1.3 x 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(0(-))(b) (Xi('-)(b)) to Xi(0(-)) and Sigma(0(-)) baryons using the form factors calculated from light-cone QCD sum rules in full theory. we obtain B(Xi(-)(b) -> Xi(-)(gamma)) = 1.08(-0.49)(+0.63) x 10(-5), which lies below the upper limit set by LHCb and is consistent with flavorsymmetry driven prediction. Our predictions on other channelsmay be checked in experiment and by other phenomenological approaches.

Automated summary

Recently, the LHCb Collaboration performed the first search for a rare radiative decay and obtained an upper limit. The measurement agrees well with existing theory prediction but shows slight tension with previous predictions. Inspired by this, we investigated other radiative decays and made predictions using light-cone QCD sum rules. Our results are consistent with previous predictions and can be verified experimentally.