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

K. Azizi,A. R. Olamaei

doi:10.1140/epjc/s10052-022-10029-1

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

K. Azizi, A. R. Olamaei

Open Access

https://doi.org/10.1140/epjc/s10052-022-10029-1

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Abstract

Recently, the LHCb Collaboration performed first search for the rare radiative Xi _{b}^{-}rightarrow Xi ^{-}gamma decay and put an upper limit, mathcal{B}(Xi _{b}^{-}rightarrow Xi ^{-}gamma ) < 1.3 times 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}) to Xi ^{0(-)} and Sigma ^{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} , 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.

Highlights

Based on the successful quark model, the ordinary hadrons are composed of either qq or qqq/qqq bound states
The matrix elements defining the Bb,c → Bl+l− flavor-changing neutral current (FCNC) processes are defined in terms of twelve form factors (FFs) in full QCD
The LHCb Collaboration put an upper limit on the branching ratio of the

Summary

Introduction

Based on the successful quark model, the ordinary hadrons are composed of either qq (meson) or qqq/qqq (baryon/antibaryon) bound states. In the limit of infinite mass for the heavy quark (m Q → ∞), one can classify the single heavy baryons due to the total flavor-spin wave function of the two remaining light quarks, which has to be symmetric because their color wave function is anti-symmetric This leads to two different representations (3⊗3 = 3⊕6) for the ground state of heavy baryons. S-wave states are necessary since they are helpful to better understand their excited states both theoretically and experimentally Investigation of their weak, electromagnetic and strong decays are of much importance. One of the most important classes of weak radiative decays is that based on b → sγ transition at quark level, which is a flavor-changing neutral current (FCNC) process. To investigate the presence of right-handed contributions, one has to measure branching fractions, angular and

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Formalism

The effective Hamiltonian

Transition amplitude twelve form factors as

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Decay width

Numerical results

Summary and conclusions

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